Van's Air Force
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Filling fiberglass weave
- Thread starter N941WR
- Start date
For the cowl I'm planning to scuff sand raw glass, squeegee epoxy, block sand, PPG DPLF and K36, block again. So for the system is working very well without the K36 over solid glass/micro, but I suspect blocked K36 will be needed to surface over honeycomb if the cell pattern is showing.
RV7Guy
Well Known Member
Two methods
First, this is not the only way but I wanted to try two method on the Van's cowl to see what worked and was easiest.
Second, READ AND DO. THIS IS VERY IMPORTANT. Before doing anything to the cowl scrub it thoroughly with a stiff brush and soap and water. I took it a step further rubbed it down thoroughly with acetone. The whole point is trying to get any contaminates from the pin holes before applying filler.
Next sand the entire cowl with 150 paper. This opens up the glass near the pin holes and other imperfections. Clean again. All major voids were now filled with microballoons and epoxy (squeegeed in) and block sanded to proper contour.
On the top (smaller) I tried microballoons and epoxy. I even used a special type of microballoons to make the job easier. The mix was applied with a fine sponge so I could press in the mix into the pin holes.
After curing I sanded and sanded and sanded
I abandon any further use of epoxy for fill.) The top was completed with Superfill and Rage and block sanded.
On the bottom, I used Superfill. I brushed it on but you could roll it as well. I found the roller would "pull" the primer back out after you rolled. I "finger painted" Superfill into any obvious areas. Superfill sands like butter and I did the lower in a fraction of the time.
After I thought it was good, I sprayed a heavy coat of Superfill onto both pieces. A few more imperfections were noted and filled. The entire cowl was block sanded wet with 320 wet and dry and most all of the primer was removed.
Now, I sprayed a guide coat of black paint on the cowl. This is simply a mist of a contrasting color. Wet block sand with wet and dry 320. This the guide coat will boldly show you any low areas. If they are minor you can continue to sand and possibly even things out. If they areas are deeper they will require filling. I used Rage and Evercoat 416 for this detail.
Keep going!!!! Sand, Sand, Sand.
Also I know one person will dispute this but 35+ years of working with composites has taught me otherwise, USING ALL EPOXY FOR FILL DOES NOT MAKE IT BETTER. Technology has changed and provided us with fantastic new products to make our job easier. The modern fillers are one of them. I think some still have the old "Bondo" mentality and therefore any mixed canned filler is bad. Nothing could be farther from the truth.
Don't hesitate to ask questions. I think I can help take the sting out of the glass work.
First, this is not the only way but I wanted to try two method on the Van's cowl to see what worked and was easiest.
Second, READ AND DO. THIS IS VERY IMPORTANT. Before doing anything to the cowl scrub it thoroughly with a stiff brush and soap and water. I took it a step further rubbed it down thoroughly with acetone. The whole point is trying to get any contaminates from the pin holes before applying filler.
Next sand the entire cowl with 150 paper. This opens up the glass near the pin holes and other imperfections. Clean again. All major voids were now filled with microballoons and epoxy (squeegeed in) and block sanded to proper contour.
On the top (smaller) I tried microballoons and epoxy. I even used a special type of microballoons to make the job easier. The mix was applied with a fine sponge so I could press in the mix into the pin holes.
After curing I sanded and sanded and sanded
I abandon any further use of epoxy for fill.) The top was completed with Superfill and Rage and block sanded.On the bottom, I used Superfill. I brushed it on but you could roll it as well. I found the roller would "pull" the primer back out after you rolled. I "finger painted" Superfill into any obvious areas. Superfill sands like butter and I did the lower in a fraction of the time.
After I thought it was good, I sprayed a heavy coat of Superfill onto both pieces. A few more imperfections were noted and filled. The entire cowl was block sanded wet with 320 wet and dry and most all of the primer was removed.
Now, I sprayed a guide coat of black paint on the cowl. This is simply a mist of a contrasting color. Wet block sand with wet and dry 320. This the guide coat will boldly show you any low areas. If they are minor you can continue to sand and possibly even things out. If they areas are deeper they will require filling. I used Rage and Evercoat 416 for this detail.
Keep going!!!! Sand, Sand, Sand.
Also I know one person will dispute this but 35+ years of working with composites has taught me otherwise, USING ALL EPOXY FOR FILL DOES NOT MAKE IT BETTER. Technology has changed and provided us with fantastic new products to make our job easier. The modern fillers are one of them. I think some still have the old "Bondo" mentality and therefore any mixed canned filler is bad. Nothing could be farther from the truth.
Don't hesitate to ask questions. I think I can help take the sting out of the glass work.
Captain Avgas
Well Known Member
On the top (smaller) I tried microballoons and epoxy. I even used a special type of microballoons to make the job easier. The mix was applied with a fine sponge so I could press in the mix into the pin holes.
After curing I sanded and sanded and sanded
On the bottom, I used Superfill. I brushed it on but you could roll it as well. I found the roller would "pull" the primer back out after you rolled. I "finger painted" Superfill into any obvious areas. Superfill sands like butter and I did the lower in a fraction of the time.
After I thought it was good, I sprayed a heavy coat of Superfill onto both pieces. A few more imperfections were noted and filled. The entire cowl was block sanded wet with 320 wet and dry and most all of the primer was removed.
Dear Darwin, I'm a bit confused by what you say. Firstly you say that you abandoned epoxy as a filler and moved to Superfill. But I believe that Polyfiber's Superfill is in fact an epoxy based filler. Can you comment.
I actually used Polyfiber's Smoothprime on the empennage fairings and tips and that seemed to work OK. Are you suggesting that Smoothprime will not have enough viscosity to provide effective filling of the Vans cowl. I presume that Superfill is more like a body filler and therefore it cannot be sprayed like Smoothprime.
<<On the top (smaller) I tried microballoons and epoxy.....The mix was applied with a fine sponge so I could press in the mix into the pin holes.>>
You can't fill pinholes with microballoons. Dry micro adds pinholes due to air entrained during mixing. Even if you don't entrain air, every balloon is a hollow sphere to sand open.
Neat epoxy does fill pinholes.....and blocks nicely without the guide coat.
Never heard of a "Superfill" you can spray or roll. I'm only familiar with
PolyFiber Superfil, blue component and white component, stiffer than peanut butter, and said to be mixed in-house at PF using West epoxy, micro, and talc. Maybe you meant Featherfill?
<<Also I know one person will dispute this.....>>
Ahhh, always nice to be remembered
You can't fill pinholes with microballoons. Dry micro adds pinholes due to air entrained during mixing. Even if you don't entrain air, every balloon is a hollow sphere to sand open.
Neat epoxy does fill pinholes.....and blocks nicely without the guide coat.
Never heard of a "Superfill" you can spray or roll. I'm only familiar with
PolyFiber Superfil, blue component and white component, stiffer than peanut butter, and said to be mixed in-house at PF using West epoxy, micro, and talc. Maybe you meant Featherfill?
<<Also I know one person will dispute this.....>>
Ahhh, always nice to be remembered
RV7Guy
Well Known Member
Superfil Primer
Dear Bob,
I stand corrected. It was Evercoat "Feather fill" high build primer, not Superfill. http://www.aircraftspruce.com/menus/cm/fillers.html I purchased locally from a specialty auto paint and supply house. Just got the names mixed up.
The Polyfiber 2 part Superfill blue and white stuff is not what I'm talking about although I used it in a few areas elsewhere. Good stuff BTW.
Smooth prime is essentially a high build primer and has plenty of viscosity to accomplish the process as described. Same basic purpose, different company. I used that to do the glass work on a friends RV. That is what he had purchased. It is white in color and water based. It worked well and I used a dark spray primer for the guide coat.
Either will work fine. Prep is the key for either one.
Dear Bob,
I stand corrected. It was Evercoat "Feather fill" high build primer, not Superfill. http://www.aircraftspruce.com/menus/cm/fillers.html I purchased locally from a specialty auto paint and supply house. Just got the names mixed up.
The Polyfiber 2 part Superfill blue and white stuff is not what I'm talking about although I used it in a few areas elsewhere. Good stuff BTW.
Smooth prime is essentially a high build primer and has plenty of viscosity to accomplish the process as described. Same basic purpose, different company. I used that to do the glass work on a friends RV. That is what he had purchased. It is white in color and water based. It worked well and I used a dark spray primer for the guide coat.
Either will work fine. Prep is the key for either one.
RV7Guy
Well Known Member
Micro for pinholes
Dan,
Epoxy and microballoons work great to fill pinholes, just much more work to sand. The key is mixing with minimal filler. The mix is by no means dry. Don't know where you got this information
I am also confused why you like to attempt to discredit virtually everything I say regarding this subject. Look at my plane or the others I've done the glass work on and a few more that have followed my guidance and I think you'll see the proof is in the results. I may not know much, but I know this subject pretty well References are available.
And, as a disclaimer, the methods described are not the only way but it is a successful based on years of experience. It is a method for those who don't like or are leery of fiberglass work, to make the task tolerable, and achieve great results.
Work smarter, not harder.
DanH;187257 You can't fill pinholes with microballoons. Dry micro [I said:adds[/I] pinholes due to air entrained during mixing. Even if you don't entrain air, every balloon is a hollow sphere to sand open.
Ahhh, always nice to be remembered
Dan,
Epoxy and microballoons work great to fill pinholes, just much more work to sand. The key is mixing with minimal filler. The mix is by no means dry. Don't know where you got this information
I am also confused why you like to attempt to discredit virtually everything I say regarding this subject. Look at my plane or the others I've done the glass work on and a few more that have followed my guidance and I think you'll see the proof is in the results. I may not know much, but I know this subject pretty well
References are available.And, as a disclaimer, the methods described are not the only way but it is a successful based on years of experience. It is a method for those who don't like or are leery of fiberglass work, to make the task tolerable, and achieve great results.
Work smarter, not harder.
Featherfill
Perhaps a few comments from a composite forum may clear this up for the metal benders here:
I'm just about finished with stripping and refinishing my wings (due to the
dreaded featherfill problem),
Featherfill laid a number of years ago on the fuse of my VE by a
previous owner, has cracked in places and small 1 inch pieces can be
lifted off with a fingernail. There seems to be no bond in places
between the Featherfill and the fibreglass beneath.
You are right, Greg. You can use epoxy on polyester but not the other way
around.
Featherfill was used by Burt early on with the Vari-eze, but later found to
come off in large sheets. DO NOT use this product on anything but your hotrod.
We have been using West System or equivalent for years for gross filling, and
acrylic urethane high build with micro added for final fill.
That 'stuff' you are talking about is probably Featherfill, a heavy
> sprayable polyester filler recommended by Burt early on. He had designed a
>
> great airplane early on, but mis-fired on that one. Polyester will not
> stick to epoxy based laminates for the long haul.
the Featherfill
base sucks up the solvent from the primer. The solvent gets locked in when
the primer cures. When the plane is finally left out in the hot sun, the
trapped solvent erupts and forms blisters. They split and this pus-like
stuff runs out.
My only cure was to remove all the finish paint, the primer
and, finally, the Featherfill right down to the fiber glass. The repair
involved starting over with micro made from West Epoxy as the contour
filler. It has taken me years to complete the project which I did in
stages.
the
recommended fill over micro was "Featherfill", which I used. Over the
years I have had some problems with local delaminations of the paint
(blistering) and in some areas paint coming off when pulling tape off
that had been used just overnight to seal the canopy.
Invariably inspection of the underlying surface has shown that the delam
was between the micro and "Featherfill". The adhesion quality of that
stuff, needless to say 'sucks'.
My humble opinion, stay away from "Featherfill". There are better
alternatives out on the market today
Still want to use it?
Perhaps a few comments from a composite forum may clear this up for the metal benders here:
I'm just about finished with stripping and refinishing my wings (due to the
dreaded featherfill problem),
Featherfill laid a number of years ago on the fuse of my VE by a
previous owner, has cracked in places and small 1 inch pieces can be
lifted off with a fingernail. There seems to be no bond in places
between the Featherfill and the fibreglass beneath.
You are right, Greg. You can use epoxy on polyester but not the other way
around.
Featherfill was used by Burt early on with the Vari-eze, but later found to
come off in large sheets. DO NOT use this product on anything but your hotrod.
We have been using West System or equivalent for years for gross filling, and
acrylic urethane high build with micro added for final fill.
That 'stuff' you are talking about is probably Featherfill, a heavy
> sprayable polyester filler recommended by Burt early on. He had designed a
>
> great airplane early on, but mis-fired on that one. Polyester will not
> stick to epoxy based laminates for the long haul.
the Featherfill
base sucks up the solvent from the primer. The solvent gets locked in when
the primer cures. When the plane is finally left out in the hot sun, the
trapped solvent erupts and forms blisters. They split and this pus-like
stuff runs out.
My only cure was to remove all the finish paint, the primer
and, finally, the Featherfill right down to the fiber glass. The repair
involved starting over with micro made from West Epoxy as the contour
filler. It has taken me years to complete the project which I did in
stages.
the
recommended fill over micro was "Featherfill", which I used. Over the
years I have had some problems with local delaminations of the paint
(blistering) and in some areas paint coming off when pulling tape off
that had been used just overnight to seal the canopy.
Invariably inspection of the underlying surface has shown that the delam
was between the micro and "Featherfill". The adhesion quality of that
stuff, needless to say 'sucks'.
My humble opinion, stay away from "Featherfill". There are better
alternatives out on the market today
Still want to use it?
RV7Guy
Well Known Member
Feather fill
Sounds like they were using it almost like layered filler instead of for pin holes. That is how I used it. There is nowhere on any work I've done where there would be a layer of it. After spraying and filling pinholes the entire cowl was sanded to remove all of the primer except that filling pin holes. I could see it coming off if used as described in your post.
Can't dispute the information except with the positive results I've had.
If the surface wasn't prepped properly you won't get proper bonding no matter what you are using. This would probably come as surprise to those have used Feather fill for years and don't have paint flying off.
Smooth Prime, a polyurathane, might be a better choice. It worked fine when I used it. Easy to apply and sand.
Interesting information.
Sounds like they were using it almost like layered filler instead of for pin holes. That is how I used it. There is nowhere on any work I've done where there would be a layer of it. After spraying and filling pinholes the entire cowl was sanded to remove all of the primer except that filling pin holes. I could see it coming off if used as described in your post.
Can't dispute the information except with the positive results I've had.
If the surface wasn't prepped properly you won't get proper bonding no matter what you are using. This would probably come as surprise to those have used Feather fill for years and don't have paint flying off.
Smooth Prime, a polyurathane, might be a better choice. It worked fine when I used it. Easy to apply and sand.
Interesting information.
Ramendala
Active Member
I have never finished a RV cowl, but this method worked on a Rebel cowl.
Here is some more information. I have done this on my cozy and it works amazing. That is all I can say. (except do NOT use a poly filler like featherfill...see earlier comments)
Check out this link. Wayne Hicks adapted Cory Bird's method. For those who do not know, Cory designed and built "Symmetry" and works for Scaled. This is the most beautifully finished plane on the planet and is all done by hand.
Cory's plane: http://www.sportsmanpilot.com/AL/articles/spr2003/Spring2003.htm
Here is Wayne's link:
http://www.maddyhome.com/canardpages/pages/waynehicks/chapter_25.htm
Ryan
Here is some more information. I have done this on my cozy and it works amazing. That is all I can say. (except do NOT use a poly filler like featherfill...see earlier comments)
Check out this link. Wayne Hicks adapted Cory Bird's method. For those who do not know, Cory designed and built "Symmetry" and works for Scaled. This is the most beautifully finished plane on the planet and is all done by hand.
Cory's plane: http://www.sportsmanpilot.com/AL/articles/spr2003/Spring2003.htm
Here is Wayne's link:
http://www.maddyhome.com/canardpages/pages/waynehicks/chapter_25.htm
Ryan
<<Dan uses PPG's epoxy primer on fiberglass, which is something I would never do. ....an application for which it was never intended.>>
Check the PPG data sheet.
<< DPLF is an anticorrision epoxy primer, not a high-build pinhole filler.>>
Correct, not a pinhole filler. Pinholes were eliminated at the previous step with neat epoxy but I may get one or two if I sanded through the epoxy while blocking. A light cross coat of DPLF serves two purposes, (1) a pinhole and surface check, and (2) a wet-on-wet tie coat between the epoxy substrate and subsequent coatings. If no defects I can spray K36 (or K38) immediately. Or I can let it cure, sand it, and spray another cross coat later immediately prior to K36 or topcoat.
I had a peel problem on a previous project; PPG K200 pulled off a bare glass substrate at about 5 years. The DPLF tie coat was recommended by my PPG factory rep to eliminate the possibility on this project.
Your proceedure and mine are very similar, the only real difference being the tie coat.
Check the PPG data sheet.
<< DPLF is an anticorrision epoxy primer, not a high-build pinhole filler.>>
Correct, not a pinhole filler. Pinholes were eliminated at the previous step with neat epoxy but I may get one or two if I sanded through the epoxy while blocking. A light cross coat of DPLF serves two purposes, (1) a pinhole and surface check, and (2) a wet-on-wet tie coat between the epoxy substrate and subsequent coatings. If no defects I can spray K36 (or K38) immediately. Or I can let it cure, sand it, and spray another cross coat later immediately prior to K36 or topcoat.
I had a peel problem on a previous project; PPG K200 pulled off a bare glass substrate at about 5 years. The DPLF tie coat was recommended by my PPG factory rep to eliminate the possibility on this project.
Your proceedure and mine are very similar, the only real difference being the tie coat.
LettersFromFlyoverCountry
Well Known Member
Maybe it's just me, but has anybody noticed there's been a weird change in the "force" on the, um, Force (VAF) lately?
The RV community used to be a group of like-minded individuals and the sense of camaraderie was overwhelming.
Now, the community seems to be like just about every other one out there -- people throwing bombs over the fence, etc.
What the heck happened? And is it too late for us to go back being a bunch of folks with a fascinating avocation who valued friendship and camaraderie above the need to be right... or whatever stupid battle happened to be fought on a given day?
It's taking a lot of the fun out of being an RVer, I have to admit.
The RV community used to be a group of like-minded individuals and the sense of camaraderie was overwhelming.
Now, the community seems to be like just about every other one out there -- people throwing bombs over the fence, etc.
What the heck happened? And is it too late for us to go back being a bunch of folks with a fascinating avocation who valued friendship and camaraderie above the need to be right... or whatever stupid battle happened to be fought on a given day?
It's taking a lot of the fun out of being an RVer, I have to admit.
Norman CYYJ
Well Known Member
Maybe it will get better when the days get longer and the sun starts to shine more.
On the inside of the cowls I lightly sand the glass, mix up some epoxy and cut it one to one with acetone and brush it on. I seems to fill the pin holes and that is all I do. After years of use the inside still holds paint and is not peeling. If you use this mixture don't expect there to be any strength to the epoxy it just fill the millions of pin holes quickly.
On the inside of the cowls I lightly sand the glass, mix up some epoxy and cut it one to one with acetone and brush it on. I seems to fill the pin holes and that is all I do. After years of use the inside still holds paint and is not peeling. If you use this mixture don't expect there to be any strength to the epoxy it just fill the millions of pin holes quickly.
Bob's right.
The personal snipping stops now. I have no tolerance for this stuff and will ban the next account that does it for a month. Think I'm kidding?
Now, please return to helful, civil discourse (please).
b,
dr
gbrasch
Well Known Member
Not to beat a dead horse, "but"...
I can't agree more with Bob and Doug. I have gotten to the point that I hardly look around here anymore. Seems like the older guys that know what is going on are burning out on all the self-professed experts, and leaving. So the cycle will start over with folks re-inventing the wheel. Personally? I am shutting off my computer and going back to building my RV, and flying my low and slow 55 year old Tri-Pacer.
I can't agree more with Bob and Doug. I have gotten to the point that I hardly look around here anymore. Seems like the older guys that know what is going on are burning out on all the self-professed experts, and leaving. So the cycle will start over with folks re-inventing the wheel. Personally? I am shutting off my computer and going back to building my RV, and flying my low and slow 55 year old Tri-Pacer.
I had good results doing as vans reccomended by thinning west systems with acetone about 50/50 and brushing on, then sanding between coats, about three coats worked for me. Lighten up troops, enjoy the sharing of information even if you don't agree, this is supposed to be fun.
Mike S
Senior Curmudgeon
For prepreg parts, that dont need any damage repairs, or surface buildup, I have has good luck with straight epoxy, brushed on and then gently heated with a heat gun used for model airplane covering, or an old hair dryer. DONT use a high temp heat gun like for stripping paint. Stipple the area as you heat it, and squeegee off the excess epoxy-----lot easier than sanding.
This is for pinholes and very slight weave filling.
In the case of a wet layup------like you might do on an intersection fairing for instance, the process is different. When done correctly, a wet layup will have a large amount of the weave showing, and it is quicker to fill the weave with micro slurry------I favor dry as I can get it. Again, heat the area you are working with low heat gun, squeegee in well, and remove the excess. After filling the weave to a level surface, go with the straight epoxy as above to fill the pinholes and "micro" pores.
Once the surface is sealed, proceed with your favorite hi fill primer/surfacer.
I have had good luck with "FeatherFill" in the past, not sure what is out there nowadays.
No matter how you choose to do this job, having the parts clean is absolutely mandatory, if you want things to go well, and last a long time. Sanding dust, wax, oil, grease, ETC will really make your job a pain. The pinholes in prepreg really like to hold onto just about anything you can think of in the debris dept., and really dont like to take on epoxy-------surface tension of the liquid epoxy will "bridge" over the pinhole. You must force the resin into the holes.
Good luck.
This is for pinholes and very slight weave filling.
In the case of a wet layup------like you might do on an intersection fairing for instance, the process is different. When done correctly, a wet layup will have a large amount of the weave showing, and it is quicker to fill the weave with micro slurry------I favor dry as I can get it. Again, heat the area you are working with low heat gun, squeegee in well, and remove the excess. After filling the weave to a level surface, go with the straight epoxy as above to fill the pinholes and "micro" pores.
Once the surface is sealed, proceed with your favorite hi fill primer/surfacer.
I have had good luck with "FeatherFill" in the past, not sure what is out there nowadays.
No matter how you choose to do this job, having the parts clean is absolutely mandatory, if you want things to go well, and last a long time. Sanding dust, wax, oil, grease, ETC will really make your job a pain. The pinholes in prepreg really like to hold onto just about anything you can think of in the debris dept., and really dont like to take on epoxy-------surface tension of the liquid epoxy will "bridge" over the pinhole. You must force the resin into the holes.
Good luck.
Keep The Building Tips Coming
Since I'm very close to sealing my fiberglass, I'm interested in this topic. I have to re-energize my memory banks and try to remember how I sealed all the fiberglass parts on my One Design. Or, I'll just call Doug Dodge of Acro Specialties in Bay City MI who probably suggested how I do it.
However, this verbal jousting on how to prepare the cowls does remind me of some very rough times when I first started working for my uncle (also know as Ivan the Terrible). He had bought a certain manufacturing process from a firm in Germany. Part of the deal was they would send a chemist over to get us started. That was also probably the worst 3 weeks of that chemist's life too after what my uncle put him through when nothing would work "like it does in Germany".
Basically, what the problem was in this very critical application, was things like the differences in water, temperature, and general humidity.
I guess what I'm trying to say, is what works in one part of the county, might not work as well in another part of the country, without perhaps one additional step in the procedure...as we had to discover many many years ago.
Take this for what it's worth, and please keep the tips coming
Regards
Jack
RV9A
N99552 (first flight before the Spring /08)
Since I'm very close to sealing my fiberglass, I'm interested in this topic. I have to re-energize my memory banks and try to remember how I sealed all the fiberglass parts on my One Design. Or, I'll just call Doug Dodge of Acro Specialties in Bay City MI who probably suggested how I do it.
However, this verbal jousting on how to prepare the cowls does remind me of some very rough times when I first started working for my uncle (also know as Ivan the Terrible). He had bought a certain manufacturing process from a firm in Germany. Part of the deal was they would send a chemist over to get us started. That was also probably the worst 3 weeks of that chemist's life too after what my uncle put him through when nothing would work "like it does in Germany".
Basically, what the problem was in this very critical application, was things like the differences in water, temperature, and general humidity.
I guess what I'm trying to say, is what works in one part of the county, might not work as well in another part of the country, without perhaps one additional step in the procedure...as we had to discover many many years ago.
Take this for what it's worth, and please keep the tips coming
Regards
Jack
RV9A
N99552 (first flight before the Spring /08)
Captain Avgas
Well Known Member
Don't tas me bro
Doug, with due respect (and I mean that), I disagree entirely with Bob Collins. I think that Vans Airforce can afford a bit of thrust and parry. We're all grown up men and the world is basically competitive. It is therefore not unreasonable for Vans Airforce to reflect that fact.
In reality I sense that VansAirforce has become so progressively censored that it is threatening to become an entirely filtered affair...a bit puerile actually. Even posts that are just mildly cynical are being removed by overzealous moderators.
I don't think that any post on this particular thread has grossly overstepped the mark at all. Totally censoring Dan Horton's post was uncalled for. He made a very valid technical point in that post about the dangers of mix and matching different manufacturers products. You threw out the baby with the bath water.
Don't go too antiseptic Doug. A lot of the people who are frequent contributors of real and meaningful data and knowledge to this forum are by their nature very opinionated...it comes with the territory. Vans Airforce will be all the poorer if they are driven away. It worries me somewhat when I see contributors of the calibre of Dan Horton and George Jetpilot being censored over what could only be considered as very minor lapses of decorum.
Personally I'm quite prepared to put up with the occasional argy bargy as long as it's accompanied by interesting information and/or intelligent discourse. Goodness, sometimes it's actually quite entertaining.
Doug, with due respect (and I mean that), I disagree entirely with Bob Collins. I think that Vans Airforce can afford a bit of thrust and parry. We're all grown up men and the world is basically competitive. It is therefore not unreasonable for Vans Airforce to reflect that fact.
In reality I sense that VansAirforce has become so progressively censored that it is threatening to become an entirely filtered affair...a bit puerile actually. Even posts that are just mildly cynical are being removed by overzealous moderators.
I don't think that any post on this particular thread has grossly overstepped the mark at all. Totally censoring Dan Horton's post was uncalled for. He made a very valid technical point in that post about the dangers of mix and matching different manufacturers products. You threw out the baby with the bath water.
Don't go too antiseptic Doug. A lot of the people who are frequent contributors of real and meaningful data and knowledge to this forum are by their nature very opinionated...it comes with the territory. Vans Airforce will be all the poorer if they are driven away. It worries me somewhat when I see contributors of the calibre of Dan Horton and George Jetpilot being censored over what could only be considered as very minor lapses of decorum.
Personally I'm quite prepared to put up with the occasional argy bargy as long as it's accompanied by interesting information and/or intelligent discourse. Goodness, sometimes it's actually quite entertaining.
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Great subject line, Bob <grin>.
I agree with a lot of what you're saying, actually. But, there is also a lot of looking the other way already in place, lots of talk of politics, etc that don't get removed. Personally, if 7 in 10 posts are 'mostly' in the rules envelope I'm perfectly pleased.
Historically, I've seen these things run cyclical. For a month or two things are swell, then something blows up and a few folks go at it like beta fish (my term for this character trait). Then folks say 'later' and I get a bunch of email. I usually look the other way (7,000 alpha males in one room...there's going to be friction), but when the replies get personal and unfriendly I take action.
I catch some heat in other boards for running the thing the way I do, but I honestly believe that most of the folks are glad the rules (as they are) are in place. The registration numbers for the past three years reflect that, also, with an average of nearly (7) folks registering per day.
I really liked that subject line in your post..made me laugh out loud. <g>.
b,
dr
I agree with a lot of what you're saying, actually. But, there is also a lot of looking the other way already in place, lots of talk of politics, etc that don't get removed. Personally, if 7 in 10 posts are 'mostly' in the rules envelope I'm perfectly pleased.
Historically, I've seen these things run cyclical. For a month or two things are swell, then something blows up and a few folks go at it like beta fish (my term for this character trait). Then folks say 'later' and I get a bunch of email. I usually look the other way (7,000 alpha males in one room...there's going to be friction), but when the replies get personal and unfriendly I take action.
I catch some heat in other boards for running the thing the way I do, but I honestly believe that most of the folks are glad the rules (as they are) are in place. The registration numbers for the past three years reflect that, also, with an average of nearly (7) folks registering per day.
I really liked that subject line in your post..made me laugh out loud. <g>.
b,
dr
Doug, with due respect (and I mean that), I disagree entirely with Bob Collins. I think that Vans Airforce can afford a bit of thrust and parry. We're all grown up men and the world is basically competitive. It is therefore not unreasonable for Vans Airforce to reflect that fact.
In reality I sense that VansAirforce has become so progressively censored that it is threatening to become an entirely filtered affair...a bit puerile actually. Even posts that are just mildly cynical are being removed by overzealous moderators.
I don't think that any post on this particular thread has grossly overstepped the mark at all. Totally censoring Dan Horton's post was uncalled for. He made a very valid technical point in that post about the dangers of mix and matching different manufacturers products. You threw out the baby with the bath water.
Don't go too antiseptic Doug. A lot of the people who are frequent contributors of real and meaningful data and knowledge to this forum are by their nature very opinionated...it comes with the territory. Vans Airforce will be all the poorer if they are driven away. It worries me somewhat when I see contributors of the calibre of Dan Horton and George Jetpilot being censored over what could only be considered as very minor lapses of decorum.
Personally I'm quite prepared to put up with the occasional argy bargy as long as it's accompanied by interesting information and/or intelligent discourse. Goodness, sometimes it's actually quite entertaining.
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AlexPeterson
Well Known Member
I used acetone thinned out lacquer putty (can't remember the new name for that stuff). Anyway, it was a 3M product in an oversized toothpaste tube. I thinned it quite a bit, maybe to the consistency of liquid hand soap.
I think I might have also positioned myself about two feet away and cussed as loud as I could at the pinholes.
In any case, some combination of those things worked.
That being said, the pinholes are minor compared to all the changes that will happen over the next few years to mess up your nice finish. It is easy to see the honeycomb pattern now in my cowl (I have one of the first epoxy cowls, maybe the newer ones are better). For the next one I build, I'm painting all the fiberglass stuff flat black, and throwing it out in the backyard for a summer before doing anything on it. Let the sun bake 'em a while.
I think I might have also positioned myself about two feet away and cussed as loud as I could at the pinholes.
In any case, some combination of those things worked.
That being said, the pinholes are minor compared to all the changes that will happen over the next few years to mess up your nice finish. It is easy to see the honeycomb pattern now in my cowl (I have one of the first epoxy cowls, maybe the newer ones are better). For the next one I build, I'm painting all the fiberglass stuff flat black, and throwing it out in the backyard for a summer before doing anything on it. Let the sun bake 'em a while.
<<I don't think that any post on this particular thread has grossly overstepped the mark at all. >>
Bob, thank you for the defense, but I support the idea of moderated forums. The post was written to be concise, but Doug didn't like the tone, a common problem with plain speech in text format. It was not something I would hesitate to say in person, in the polite company of strangers, but any moderator may delete at will. Those are the rules.
Doug, a word, and just a word, neither threat nor challenge. Experienced builders give far more than they get; some were using a Gold Lindy as a paperweight a long time before VAF came to pass. We're volunteers, not employees. For a volunteer with a time investment, being banned would not be seen as a burden. Do be careful; I wish you success with this venture.
Bob, thank you for the defense, but I support the idea of moderated forums. The post was written to be concise, but Doug didn't like the tone, a common problem with plain speech in text format. It was not something I would hesitate to say in person, in the polite company of strangers, but any moderator may delete at will. Those are the rules.
Doug, a word, and just a word, neither threat nor challenge. Experienced builders give far more than they get; some were using a Gold Lindy as a paperweight a long time before VAF came to pass. We're volunteers, not employees. For a volunteer with a time investment, being banned would not be seen as a burden. Do be careful; I wish you success with this venture.
I've gotta agree with DanH on his last point. Some of the experienced builders have a tendency to cop an attitude when giving advice, but I would much prefer that to a VAF site composed of nothing but polite novice builders. I'm still waiting for an answer to my previous post, but fear that the guidelines have scared off those with an answer.
N941WR
Legacy Member
Drifting back on course
Gang,
What is the best way to fill the weave on the fiberglass cowl? The imperfections I'm seeing are MUCH larger than just pin holes. They are about 1/4 to 1/2 the thickness of the fiberglass cloth because it is that cloth that is sticking up.
Thanks!
Gang,
What is the best way to fill the weave on the fiberglass cowl? The imperfections I'm seeing are MUCH larger than just pin holes. They are about 1/4 to 1/2 the thickness of the fiberglass cloth because it is that cloth that is sticking up.
Thanks!
Will be using Sherwin-Williams Jet Glo on my RV-6 and got a news letter with an article about Spread N Spray spot primer. SW Account Executive Brad Berntson said "The people at Piper told me it was taking them as many as 18 hours to fill all the typical pinholes and voids in fiberglass and composite surfaces...Since Piper approved Spread N Spray, the application time has been cut dramatically."
This is a relatively new Sherwin-Williams product.
Something else to consider. If I try it I'll give a report.
Ken
This is a relatively new Sherwin-Williams product.
Something else to consider. If I try it I'll give a report.
Ken
Mike S
Senior Curmudgeon
For what you are describing, I would use a dry micro mix to bring it up level, then straight epoxy to seal.
Go back and read post 20, there is more detail there.
az_gila
Well Known Member
Polyester on glass
I have to comment politely on this statement....
Most sailplanes re-finished in the US use a polyester primer and paint over the factory epoxy structure.
My Mini-Nimbus was re-finished this way about 20 years ago, and still has a great finish.
The old, yellowed and crazed German finish (which only lasted about 12 years in TX) was removed by grinding, a polyester primer sprayed on, and sanded off, and an industrial polyester white paint sprayed on and polished as a final surface.
Polyester on epoxy is a standard in the sailplane world, where smooth glass-like finishes and absolutely no pinholes are expected.
The specific products used are made by Simtec in S. Calif....
http://www.simteccoatings.com/index2.ivnu
Please note I'm not recommending this for Vans cowls... just pointing out that a major group of flying machines do use polyester coatings on an epoxy substrate...
One issue might be the surface finish before priming.... under the guidance of one of the premier glider repair facilities, I did my fuselage... the old finish was ground off using 80 grit paper. This gave a good mechanical bond.... you want "smooth lines" at this stage, but you don't want a slick surface. This might have been some of the past problems folks have had with Feather Fill - you need the scratches for a physical bond.
gil A
I have to comment politely on this statement....
Most sailplanes re-finished in the US use a polyester primer and paint over the factory epoxy structure.
My Mini-Nimbus was re-finished this way about 20 years ago, and still has a great finish.
The old, yellowed and crazed German finish (which only lasted about 12 years in TX) was removed by grinding, a polyester primer sprayed on, and sanded off, and an industrial polyester white paint sprayed on and polished as a final surface.
Polyester on epoxy is a standard in the sailplane world, where smooth glass-like finishes and absolutely no pinholes are expected.
The specific products used are made by Simtec in S. Calif....
http://www.simteccoatings.com/index2.ivnu
Please note I'm not recommending this for Vans cowls... just pointing out that a major group of flying machines do use polyester coatings on an epoxy substrate...
One issue might be the surface finish before priming.... under the guidance of one of the premier glider repair facilities, I did my fuselage... the old finish was ground off using 80 grit paper. This gave a good mechanical bond.... you want "smooth lines" at this stage, but you don't want a slick surface. This might have been some of the past problems folks have had with Feather Fill - you need the scratches for a physical bond.
gil A
<< Sherwin-Williams....Spread N Spray spot primer.>>
Product data sheets and MSDS at:
http://cfm.swaerospace.com/product_information/index.cfm?banner=Primers.gif&catid=10
Interesting stuff. Judging from the MSDS it seems to be a sprayable epoxy primer with the addition of sanding filler solids. You add "CM0120922 Spreadable Spot Primer Adduct" to transform it into a paste. The MSDS for the adduct is worth a read; eye, skin, and lung burns, so use caution if you try it.
Product data sheets and MSDS at:
http://cfm.swaerospace.com/product_information/index.cfm?banner=Primers.gif&catid=10
Interesting stuff. Judging from the MSDS it seems to be a sprayable epoxy primer with the addition of sanding filler solids. You add "CM0120922 Spreadable Spot Primer Adduct" to transform it into a paste. The MSDS for the adduct is worth a read; eye, skin, and lung burns, so use caution if you try it.
Captain Avgas
Well Known Member
To thin or not
The West System's site http://www.westsystem.com/ carries an article on thinning epoxy. Just search on "thinning".
The article states that adding just 5% acetone to epoxy reduces the viscosity by 60%...but reduces the epoxy's compressive strength by 35%. The article describes this as a "big hit in the mechanical properties". So I wonder what happens when you mix in 50% thinner.
When others are talking about using raw epoxy to fill pinholes are they using it thinned or unthinned. If they are thinning, what are they using and in what percentage....and does the process have manufacturer's recommendation.
The West System's site http://www.westsystem.com/ carries an article on thinning epoxy. Just search on "thinning".
The article states that adding just 5% acetone to epoxy reduces the viscosity by 60%...but reduces the epoxy's compressive strength by 35%. The article describes this as a "big hit in the mechanical properties". So I wonder what happens when you mix in 50% thinner.
When others are talking about using raw epoxy to fill pinholes are they using it thinned or unthinned. If they are thinning, what are they using and in what percentage....and does the process have manufacturer's recommendation.
Mike S
Senior Curmudgeon
As I have mentioned above, I use heat to thin the epoxy in the area I am working, and I stipple it well while it is still thin from the heat. Be careful, too much heat will cause problems.
Stipple, FYI, refers to using a paint brush with the bristles cut back to only a half inch or less in length, and forcing the epoxy into the surface by repeatedly "stabbing" the part with the brush.
K36
Think Dan is using PPG K36 Prima (high-build sandable primer). Spray is best, but it can be rolled and tipped with a brush...
Mike
Think Dan is using PPG K36 Prima (high-build sandable primer). Spray is best, but it can be rolled and tipped with a brush...
Mike
Inviting Suggestions for the next step
I started surfacing my cowlings as follows:
1.Cotton flock to build up front behind spinner for a flat surface and an even space of 1/4 inch behind the spinner plate.
2. Block sand with 80 grit.
3. Micro balloons to fill larger, obvious surface areas.
4. One coat of West Systems thinned 50/50 with acetone. This took 48 hours to dry which I didn't expect. Is this normal?
5. Block sanded with 80 grit.
6. One to two coats of EverCoat Glaze Coat. I sanded this mostly off so the pin holes and low spots were filled. 80 grit followed by 100.
I'm not sure what to do next. I'm thinking of another coat of thinned epoxy to seal the EverCoat and toughen the surface. I expect to hit the paint booth in late March or April. I would use the epoxy now and do the final sanding just prior to paint.
Looking for suggestions on the next step from those that have gone before me.
Jekyll
7a Slider, baffles just about done. Now I know why they are called baffles. They BAFFLED me for quite a while
I started surfacing my cowlings as follows:
1.Cotton flock to build up front behind spinner for a flat surface and an even space of 1/4 inch behind the spinner plate.
2. Block sand with 80 grit.
3. Micro balloons to fill larger, obvious surface areas.
4. One coat of West Systems thinned 50/50 with acetone. This took 48 hours to dry which I didn't expect. Is this normal?
5. Block sanded with 80 grit.
6. One to two coats of EverCoat Glaze Coat. I sanded this mostly off so the pin holes and low spots were filled. 80 grit followed by 100.
I'm not sure what to do next. I'm thinking of another coat of thinned epoxy to seal the EverCoat and toughen the surface. I expect to hit the paint booth in late March or April. I would use the epoxy now and do the final sanding just prior to paint.
Looking for suggestions on the next step from those that have gone before me.
Jekyll
7a Slider, baffles just about done. Now I know why they are called baffles. They BAFFLED me for quite a while
Fiberglass Finishing
Jekyll,
1. Cure time is affected by temp, hardener, etc. and thinning may have extended your cure time. If you can sand it and it turns into dust vs. clumping on the sandpaper you should be OK.
2. FWIW, I've had good results with the following sequence:
Lightly sand w/80 grit.
Apply micro-balloon filler.
Lightly sand w/80 grit.
Seal w/epoxy.
Lightly sand w/80 grit; don?t sand into glass?if you accidentally sand into the glass layer, reseal with epoxy.
Allow epoxy to cure completely; see manufacturer recommendations
Prime with DPLF40 epoxy primer (see http://www.pwpaints.com/images/downloads/dplf-p-196.pdf) and cure.
[note: defects will be highlighted by the primer]
Sand with 150 grit.
Fill defects w/Microlight or epoxy w/micro-balloons if defect is deep
Sand newly filled areas w/150 grit.
Reseal filled areas w/epoxy (no filler).
Sand entire piece with 150 grit (looking for matte finish).
Sand w/220 grit.
If surface still doesn?t make you happy, prime with K36 Prima high-build epoxy primer (see http://www.pwpaints.com/images/downloads/k36p-p-169p.pdf).
Apply final coat of DPLF40; cure.
Final sand w/220 or 320 grit.
Paint.
3. Based on the work you've already done, I'd recommend you seal with epoxy and then prime a couple of days before painting.
4. Note: most primers must be painted within one week; if you miss the 'window' for repainting they should be cleaned, resanded, cleaned again, followed by a fresh coat of primer. Once this fresh coat of primer is dry, paint may be applied. This is required to ensure a good bond between primer and paint. See product info sheets for the primer and paint you intend to use.
Mike
Jekyll,
1. Cure time is affected by temp, hardener, etc. and thinning may have extended your cure time. If you can sand it and it turns into dust vs. clumping on the sandpaper you should be OK.
2. FWIW, I've had good results with the following sequence:
Lightly sand w/80 grit.
Apply micro-balloon filler.
Lightly sand w/80 grit.
Seal w/epoxy.
Lightly sand w/80 grit; don?t sand into glass?if you accidentally sand into the glass layer, reseal with epoxy.
Allow epoxy to cure completely; see manufacturer recommendations
Prime with DPLF40 epoxy primer (see http://www.pwpaints.com/images/downloads/dplf-p-196.pdf) and cure.
[note: defects will be highlighted by the primer]
Sand with 150 grit.
Fill defects w/Microlight or epoxy w/micro-balloons if defect is deep
Sand newly filled areas w/150 grit.
Reseal filled areas w/epoxy (no filler).
Sand entire piece with 150 grit (looking for matte finish).
Sand w/220 grit.
If surface still doesn?t make you happy, prime with K36 Prima high-build epoxy primer (see http://www.pwpaints.com/images/downloads/k36p-p-169p.pdf).
Apply final coat of DPLF40; cure.
Final sand w/220 or 320 grit.
Paint.
3. Based on the work you've already done, I'd recommend you seal with epoxy and then prime a couple of days before painting.
4. Note: most primers must be painted within one week; if you miss the 'window' for repainting they should be cleaned, resanded, cleaned again, followed by a fresh coat of primer. Once this fresh coat of primer is dry, paint may be applied. This is required to ensure a good bond between primer and paint. See product info sheets for the primer and paint you intend to use.
Mike
N941WR
Legacy Member
I'm finshed
Last night I finished the bottom cowl.
After ordering some WonderFil some time back and not hearing from the company I elected to use the un-open Superfil I had on my shelf. Funny thing, the WonderFil arrived last night, the same day as my last sanding session.
Here is what I did:
1. Lightly hand sanded the cowl with 80 grit.
2. Using a random orbital sander and 220 grit paper, I sanded the cowl some more. (Don't forget your dust mask and eye protection.)
3. Vacuumed the cowl with a brush attachment
4. Vacuumed the floor and general area
5. Wiped the cowl clean with acetone
6. Blew the cowl clean with very high pressure from the compressor
7. Wiped the cowl clean with acetone a 2nd time.
8. Squeegee on a thin layer of Superfil by spreading it one direction and then going over it a second time at a 90 degree angle to the first layer. The layer should be as thin as you can make it. The goal here is to fill the pin-holes, not build up another layer of epoxy.
9. Let harden overnight
10. Repeat steps 2 through 9 as needed. Usually three sessions of Superfil is enough.
I can't wait to have it painted to see how successful I was at filling all of those holes.
Last night I finished the bottom cowl.
After ordering some WonderFil some time back and not hearing from the company I elected to use the un-open Superfil I had on my shelf. Funny thing, the WonderFil arrived last night, the same day as my last sanding session.
Here is what I did:
1. Lightly hand sanded the cowl with 80 grit.
2. Using a random orbital sander and 220 grit paper, I sanded the cowl some more. (Don't forget your dust mask and eye protection.)
3. Vacuumed the cowl with a brush attachment
4. Vacuumed the floor and general area
5. Wiped the cowl clean with acetone
6. Blew the cowl clean with very high pressure from the compressor
7. Wiped the cowl clean with acetone a 2nd time.
8. Squeegee on a thin layer of Superfil by spreading it one direction and then going over it a second time at a 90 degree angle to the first layer. The layer should be as thin as you can make it. The goal here is to fill the pin-holes, not build up another layer of epoxy.
9. Let harden overnight
10. Repeat steps 2 through 9 as needed. Usually three sessions of Superfil is enough.
I can't wait to have it painted to see how successful I was at filling all of those holes.
N941WR
Legacy Member
It is not often that one gets the opportunity to work on two different cowls for the same plane. I'm (un) lucky, I guess.
I sent a note to one of my fellow chapter members who is on his second or third composite plane and here is what he suggested for filling pinholes and the fiberglass weave:
I sent a note to one of my fellow chapter members who is on his second or third composite plane and here is what he suggested for filling pinholes and the fiberglass weave:
Alex B said:Bill,
After Cory Bird took grand champ at OSH a few years back, he revealed his secret technique to fill pin holes. It's fast, easy, cheap and light weight. Here's an explanation from the Cozy forum:
06-13-2005, 11:06 AM
Wayne Hicks
Member Join Date: Aug 2002
Posts: 511
Cory Bird's Raw Epoxy Finishing Technique
________________________________________
I recently read about the finishing technique that Cory Bird used on his OSH grand champion Symmetry. The technique is dry micro, contour to 36 grit (yes, 36 grit), then skim coat and squeegee up to 5 successive coats of pure epoxy (yes, pure epoxy) to fill all pin holes and scratches. Curious, I tried a variant of it this weekend on the bottom of my wing. 4 pinholes TOTAL! Except for two small low spots near the aileron spars, I was almost ready for paint on the very first try. I am so psyched I can hardly stand it. If I was starting from scratch I would definitely give the full technique a try!
I was already contoured to 120 grit on my wings when I came across the article, so I didn?t use that many coats. In my "test case", I applied the pure WEST with a roller, waited 10 minutes, the squeegeed it all off. The pinholes were almost filled. So I applied another layer, this time lightly squeegeeing to leave a very thin layer. I probably left on too much WEST. I need to find the balance between scraping it all off and leaving barely enough on.
Anyway, I started sanding off the WEST. True, it was a little hard to sand off. But a MIRACULOUS thing occurred. Almost all the pinholes and large scratches got filled. And I'm talking about very big pinholes, like the size of small peas. Even more miraculous, because the WEST is so tough, my 3-foot sanding board (100 grit, then 120 grit) "cut" the tops off the most inconspicuous of high spots that my first contour to 120 never caught! I continued to sand, sand, sand until all the WEST was almost, almost, almost sanded away.
Steve (an exceptional hangar mate if ever there was one) sprayed the wing with primer. Like I said above, I sanded it off and was rewarded with a wing bottom that had only 4 pinholes TOTAL. For test comparison, I didn't WEST the lower winglet. Just sprayed primer over it. Of course, it was loaded with pin holes.
So what does this all mean? Since this is the first time I've ever filled, sanded, and primered ANYTHING, I have no basis for comparison. But I can vouch that skimming with WEST really does fill scratches and pinholes of all sizes. And if you're an aggressive sander like me (meaning, I have no patience, no finesse!), the hard coat left by the WEST helped me to achieve an even better contoured finish. The other obvious benefit is leaving the tiniest of WEST layer helps to harden the micro. I've heard others say that this helps prevent print-through later on in life.
__________________
Wayne Hicks
Cozy IV Plans #678
http://www.canardzone.com/forum/showthread.php?t=1322
Here's a longer post with pictures:
http://www.rvplane.com/pdf/SkimCoating.pdf
This was technique was offered in the RV forum but I don't think the metal people believed it would work. (Yes, I saw your post.
http://www.vansairforce.com/community/showthread.php?t=25421
I'll be glad to help you.
Alex
N395V
Well Known Member
The 2 fiberglass gurus I admire the most are Dan Horton and Mark Frederick, while they are not often coupled in the same discussion they are who I most often turn to in times of need.
Yes the construction of the statement was plagarized but the content is sincere. If you recognize the source you are watching too much cable news and niot spending enough time on your RV.
