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It's composite time...

Bill Boyd

Well Known Member
and despite having literally read every post of every thread in the -10 forum in the last two years to get prepared for my build, I find sometimes there are more questions than answers. Until you actually hold the parts in your hands, it's not always clear what the answers and advice mean, or what the questions/difficulties were to begin with.

I did all the composite work on my 6A two decades ago, and I'm sure I did it "wrong" compared to best practices, but somehow I powered through and made something that worked well enough for me. I want to do my best this time. I can't put it off any longer, having run out of non-composite tasks I can do on the build for now :p

Last night I pulled the cabin top out of the corner, brushed off the shop dust and cobwebs, and studied it in some detail, picking out scribe lines, cross-referencing the plans, looking at some VAF threads about how to scribe and cut and rout things to fit. Lots of heat but a disappointing amount of light and clarity -- seems like I'll have to jump in and figure most of this out as I go, hoping that having read the VAF archives will be like a med student taking gross anatomy: you won't possibly remember much of it, but you'll be a better builder for having been immersed in it at one time.

The scribe lines are there on my specimen, which is a relief. They aren't very straight, and they disappear altogether in places, but I think I can eyeball it closely enough. When I settle on a way to do the door seals, I am hoping I'll have the beginnings of a clue how to trim the door opening. Some of the better threads are missing photo links that probably would have answered a lot of questions.

I plan to buy a carbide perma-grit type blade at Lowe's aviation tonight for my 20v oscillating cutter tool, and have a HF pneumatic 3/8" belt sander for inside corners. Still lack a lot of good composite tools in the shop.

That brings up a bigger question for the guru's like DanH:

What shopping list would you recommend for a guy starting over with nothing in the way of composite tools and materials? I need to purchase some of everything I'm likely to want for the cabin, cowl, tips, pants and fairings. Resin, hardener, scales, cups, sticks, spreaders, fabric, peel-ply, cutters, mat, brushes, fillers and thickeners, release agents, foam, clay, sanding and shaping tools and supplies, personal protective equipment - the whole shebang. I'll figure out a way to get the order past the CFO, but I want to outfit the shop to the level of no-regrets from the outset of the composite phase.

If this has been answered elsewhere, forgive my waste of our bandwidth - and shoot me the link :D
 
Bill--- to start the shopping list, good dust masks is a must.

I really like the pizza cutter style rolling knife (no idea what the correct name is) for cutting the glass cloth.

m000093466_sc7


Resin------West systems epoxy works, may not be the pinnacle of things in the epoxy world, but works just fine for our needs. Ditto for the proportioning pumps they sell. If you want to be really precise get the scale and measure that way.

Get micro, flox, and cabosil. each one has a specific purpose, micro is a lightweight filler, and does virtually nothing to add strength to the matrix, and may even weaken it. It is a filler. Cabosil thickens the viscosity and makes the resin stay where you put it. Flox makes the matrix strong. You can mix the various stuff together, to get the needed properties for what you are attempting at the moment.

Spend the extra $$ for quality sandpaper.

Get lots of throw away mixing containers, paper ice cream dishes work well, wider is better than deeper IMHO. Also lots of throw away stir sticks ----- I really like the bamboo paint stirring sticks some paint stores have---you can cut them in half to get a workable size. Popsicle sticks break too easy -------specially when mixing dry micro etc.

Get lots of throw away cheap 1" paint brushes to. Sometimes you will need to cut the bristles down by 2/3 or so, this makes the brush good for stippling.

When doing the big layup at the base of the windshield consider adding black tint to the resin-------will make the inside look much better when you are in the plane.

Good luck.
 
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Since you brought it up

Mike, what is the quality sandpaper and where's the best place to get it?

I plan to treat myself to a few perma-grit sanding blocks, but OTOH not going to buy one of everything at that store.
 
What shopping list would you recommend for a guy starting over with nothing

If this has been answered elsewhere, forgive my waste of our bandwidth - and shoot me the link :D

Hi Bill,

Unlike yourself, this is my first build, and with no composite experience at all, I was very intimidated when I got to the glass/cabin top stage. I'm actually enjoying this stage for the most part. It is true, as I've read before, that this is where there is just as much thinking, planning, and researching as building - at least in my case. Between the scribe lines, on/off of fitting the top, bonding/trimming the doors, finishing the cabin top interior, door seals, door handles, door safety latches, etc, there is a lot going on!

Mike's list pretty much hits what I currently own to a T - some West 105 and 205/206, their pumps, some cabo/flox/micro from A.S., a bit of uni and bid, shears and a pizza cutter, and plenty of gloves, stir sticks, and cups. I also bought a bunch of damaged dacron covering from AS to use for peel ply. I will repeat what he said about the widest, shallowest cup you can find. The ones I bought are a bit narrow and deep which tends to make a larger batch exotherm too quickly.

It really doesn't take much to be able to continue/progress through the -10 glass stage. I continue to get tips here and from others' build logs, and, of course, I have some DanH threads book marked for periodic review. This one is one of my favs -

http://www.vansairforce.com/community/showthread.php?t=44856
 
Aircraft Spruce

Aircraft Spruce will have all the stuff you will need.

Safety Equipment:
Butyl Rubber Gloves (with cotton liners)
Dust masks​
Mixing equipment
Gram scale (buy that somewhere else)
Unwaxed mixing cups in various sizes
Tongue depressors (cut the bottom square for mixing)
Surface Preparation
Aluminum Oxide sandpaper in 36 and 80 grit
Long sanding board
Rubber automotive sanding pads
Prep-Sol wax and silicone remover
Dremel tool with Structured Carbide bits​
Application equipment
Pizza cutter
Good scissors
1" bristle brushes (cut an angle on the end for stippling)
6" Thalco Squeege (acetone resistant)
Hair Dryer
Plastic trash bags
Acetone for cleanup
Optional: Peel-Ply​
I can't speak to the type of epoxy that Vans recommends, but whatever you use needs to be stored near room temperature along with the cloth. Epoxy usually has a one-year expiration so don't buy too much at one time. You will need a clean area to store and cut the glass cloth.
 
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Home Depot sells acetone by the gallon.

Dollar store has 3 packs of paint brushes, and packs of paper cups (without wax!!!). Harbor Freight has 3 packs of paint brushes cheap also. Basically one time use.

Used a variable temp heat gun quite a bit. Amazon has some good ones for cheap.

A 5" orbital sander was indispensable for me. Bosch was my choice. 120-360 grit paper. As said before, the better ones you can find. Home Depot.

+1 for the rotary cutter wheel. Spruce for a nice one, or Walmart or craft store for a plastic one. Get an extra wheel too. A burr on the wheel will drive you crazy when you make a nice cut and it misses occasional fibers😡.

A good straight edge for cutting cloth. Aluminum yard stick works well so you have measurements also.

A pack of silicone?? mini putty blades, or squeegee. Harbor freight has some yellow ones that work well, and cheap.

West Systems worked well for me. The "calibrated" pumps got the job done.

Repurpose all your worn out good drill bits for fiberglass.

Face mask, and gloves were mentioned. I'll add, arm protection also. Wash as needed to keep the inside clean. As little exposure of the dust on your skin the better. The body can build up reactions to the glass dust from repeated exposure.
 
On the door and window scribe lines, it is critical to verify the measurements before cutting. Personally, I would recommend re-drawing those lines based on the flange dimensions given in the plans. My scribe lines were off and I'm going to have to invest some time to re-trim some areas and scarf in more material in others.

I'd have saved a lot of time by investing the 15 minutes to draw the lines myself.
 
Garage-shop cloths to take off at the door to the house to not bring in all that nasty stuff from sanding ect.
 
A few notes...

I've been using straight-sided paper cups about 30 years. Straight sides and flat bottoms can be scraped with the mixing stick for uniformity.

http://www.publix.com/p/RIO-PCI-167411?ch=14.4.5.

http://www.publix.com/p/RIO-PCI-186600?ch=14.4.5.

If exotherm is a problem, dump it out of the cup after mixing. I routinely wet out multiple plies between 4 mil plastic sheets anyway.

The big tongue depressors rarely break.

https://www.aircraftspruce.com/catalog/cmpages/mixingsticks.php?clickkey=16462

We have no use for unidirectional cloth in RV construction. Opinions vary, but the best all around fabrics to stock the shop are 7500 plain weave (heavy weight, easy to wet) and some 7781 (will wrap around a bowling ball).

Go to Harbor Freight and grab a cheap 6" orbital sander:

http://www.harborfreight.com/6-in-random-orbit-air-sander-63178.html

Now go to the local automotive paint supply (or Ebay, etc) and buy a roll of 6" 3M Gold Stickit in 80 grit. Get a small package 3 x 18 strips too, 80 and 22 grit. Glue them to birch plywood of the same size. You'll never regret good paper.

http://www.ebay.com/itm/3M-75-DISC-...818864?hash=item43dc98ee70:g:m9kAAOSwstxVX3jc

What Kyle said about scribe lines...pay attention!

I once bought squeegees, then some genius here suggested using hotel key cards. Works great.

Buy scales, not pumps. Although pumps may get the job done with West, they're useless for other epoxy, urethane and polysulfide products. Plus accurate gram scales are down to silly prices:

http://www.tomtop.com/balance-weighing-apparatus-208/p-h4118.html
 
Home Depot sells acetone by the gallon.

Dollar store has 3 packs of paint brushes, and packs of paper cups (without wax!!!). Harbor Freight has 3 packs of paint brushes cheap also. Basically one time use.

Used a variable temp heat gun quite a bit. Amazon has some good ones for cheap.

A 5" orbital sander was indispensable for me. Bosch was my choice. 120-360 grit paper. As said before, the better ones you can find. Home Depot.

+1 for the rotary cutter wheel. Spruce for a nice one, or Walmart or craft store for a plastic one. Get an extra wheel too. A burr on the wheel will drive you crazy when you make a nice cut and it misses occasional fibers��.

A good straight edge for cutting cloth. Aluminum yard stick works well so you have measurements also.

A pack of silicone?? mini putty blades, or squeegee. Harbor freight has some yellow ones that work well, and cheap.

West Systems worked well for me. The "calibrated" pumps got the job done.

Repurpose all your worn out good drill bits for fiberglass.

Face mask, and gloves were mentioned. I'll add, arm protection also. Wash as needed to keep the inside clean. As little exposure of the dust on your skin the better. The body can build up reactions to the glass dust from repeated exposure.

Good List, but add a HF scale. Small paper cups (water cups) are great for small batch patching, just a little short and other small jobs. Pay attention to the weight ratio, remember, it is not the same as volume ratio. I got the roller cutter, mat and mixing sticks at Hobby Lobby, if one is near.

BTW - Check epoxy/hardener expiration dates, some may be as short as a year, but many good ones are longer.

The selection of permanent carbide sanding tools is costly, but will save it's price in even the best sand paper. 3M green lasts longer than others, but on glass, (not just resin) the perma-grit is the longest lasting - mine functions like new after substantial use.
 
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Fibre Glast is a supplier that was recommended to me at the Synergy Air quickbuilding course, and I've had good experiences with them so far. Great website and product lines; very responsive; quick delivery and decent prices. The only possible complaint I could have is the way their online algorithms work. We've all experienced the situation of visiting a supplier website, and for awhile afterward ads will pop up in various other online sites you visit, trying to sell you the stuff you looked at earlier. Well, Fiber Glast uses that marketing technique as well... but their prompts say "Your shopping cart is still full!"... so you wonder, did I complete my purchase or not? It's just a gimmick... but I wish they knew they don't have to BS me into second guessing myself... it's not the best way to get the attention of an already loyal customer.
 
picked this up tonight

http://www.harborfreight.com/2-58-in-Carbide-Grit-Multi-Tool-Half-Moon-Blade-61834.html

I'll report back how it works. Should be trimming cabin flanges this weekend.

HF was out of 1" chip brushes tonight. Someone had filched all their 3/8 x 13 inch sander belts out of the packaging, which was still hanging on the display hooks. It's not in the best neighborhood.

I have a good line on tongue depressors and purple nitrile gloves at work (and I suspect our urinalysis specimen cups are wax-free), but I don't often stay at Holiday Inn Express, so hotel keys are not the go-to squeegees here. HF did have the yellow plastic ones, so I tossed them in the basket. Didn't see Dan's orbital sander recommendation in time to snag one tonight but we are going back to the city this weekend to see Beauty and the Beast, so I can probably divert to Horror Freight while there.

That little scale was super cool for the price! Oh, to be a nerdy kid again - but with all the stuff available now, instead of just what was hawked in the classifieds of DC Comics, Boys Life, Pop Mechanics and Edmund Scientific!:cool:
 
I found MGS Epoxy is much superior than West System. Technically it requires heat treating for full strenght but practically first exposure to hot summer sun will take care of the heat treatment. Aircraft Spruce sells it, little pricey though. I don' like West system due to the fact that it has a low TG. This may cause softening and warping when exposed to sun in a hot summer day on the tarmac.
I also found playing cards are very good in spreading epoxy. Brush doesn't work good but required for dabbing. I usually lay the fiberglass, kevlar, carbon cloth on a wax paper on the table. Pour epoxy from a cup and spread with a playing card, put the lay-up in place, again squegee the excess epoxy with a playing card. You can work any wrinkles or non conforming edges by dabbing with 1" cheap brust that its bristles were cut in half way in the middle.
Also working in the internal corners and edges, I mix epoxy with cabosil to peanut butter consistency, put it in a zip lock bag, cut one corner and apply like cake icing to make a fillet so that the lay up easily conforms the corner (edge)
If you are curious how I know these, I used to fabricate large composite model airplane fuselages for many years out of epoxy, carbon, kevlar and fiberglass.
 
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Here are a couple things I have learned

1. Hotel card keys work great for spreading epoxy

2. Sanding belts cut to size or rolled up are the best sand paper you can get. You can rip a 3x24 into 2 pieces, cut a 1x2 and cram it into the piece for a great flat sanding block. If you want bigger, get a 36" belt.

3. To remove the shine on the glass, scotch pads work great. If you have a hook-loop orbital sander, the pad will stick very well and works great for small scratches on the glass.

4. HF makes both green and red scotch 4" balls for sanding. You have to tighten the heck out of them or even replace the mandrel with a bolt and nut, but they sand great for the rounded areas on the cowl and in the FAB.

5. If using West Systems, do not use more hardener than specified to "speed it up". It will not harden properly and could stay gummy. Get the 205 hardener. I use a scale - 5-1 ratio but the pumps work well too. It is a good epoxy and all I used in an earlier life restoring show Chris Craft boats. Rutan used it as well.

6. Sail cloth works great for peal ply - much better than the plastic stuff Spruce has. Use peal ply. It will save you a ton of time.

7. Biggest tip - go to Alabama and buy a car or truck from DanH. Become his new friend.

Have fun - almost all glass screw ups can be fixed!
 
http://www.harborfreight.com/2-58-in-Carbide-Grit-Multi-Tool-Half-Moon-Blade-61834.html

I'll report back how it works. Should be trimming cabin flanges this weekend

I'm interested to hear how it works for you. I tried the same attached to a HF oscillating tool without success. Thought perhaps the blade was HF garbage, so purchased a few higher quality blades - still did not work. Perhaps it was the tool; perhaps my technique..? I ended up using the cutoff wheels that came with the kit in my die grinder. Messy, yes, but quick and effective.
 
I'm interested to hear how it works for you. I tried the same attached to a HF oscillating tool without success. Thought perhaps the blade was HF garbage, so purchased a few higher quality blades - still did not work. Perhaps it was the tool; perhaps my technique..? I ended up using the cutoff wheels that came with the kit in my die grinder. Messy, yes, but quick and effective.

There is blade that has grains of diamond or something like that which works well. I also used a jigsaw. The regular oscillating blades didn't work so well.
 
I saw the diamond blades

but I remembered someone in a thread saying they were probably too fine a grit and tended to burn the resin as they cut. I, too, wondered if a carbide jigsaw blade might be the way to go for a lot of these cuts where the material to be cut is stiff enough. I'm going to do some experimenting and post results here.
 
There is blade that has grains of diamond or something like that which works well. I also used a jigsaw. The regular oscillating blades didn't work so well.

but I remembered someone in a thread saying they were probably too fine a grit and tended to burn the resin as they cut. I, too, wondered if a carbide jigsaw blade might be the way to go for a lot of these cuts where the material to be cut is stiff enough. I'm going to do some experimenting and post results here.

Yup, that was my experience with the oscillating tool and diamond blade - burning instead of cutting. I read several posts that praised the oscillating tool, so my guess is that I just never found the right blade. I did use a glass jigsaw blade where it would fit, cutoff wheel elsewhere. Sanding drum in the die grinder for corners and Mouse palm sander to finalize the fit. I'm sure there are lots of ways to accomplish the end state. I'm just glad the worst of the cutting/fitting is behind me:D
 
Hey Stormy, good to see you back at it in a 4 seater no less...I'm sure you will have no probs getting off ur strip. Better plan to visit you again soon, if you still have 6a, we need a meet at Pik-n-pig...Red.
 
I'm here, Reno!

Drop in anytime, friend. We need to have another fly-in. Tried once a few years ago but it was too--




-- stormy :eek:
 
I haven't tried the oscillating tools, but found the large 3" disks that Van's provides were too crude, hard to control, and caused a lot of dust. What worked best for me was a Dremel tool with the small 1" diamond blades from HF. http://www.harborfreight.com/diamond-rotary-cutting-discs-5-pc-69657.html These cause a very fine cut so not a lot of dust and are easy to control. Just plan on changing the disk reasonably frequently. I think I've gone through about 5 of the packages of 5. Other builders have also said they had the best results with the Dremel tool.
 
I haven't tried the oscillating tools, but found the large 3" disks that Van's provides were too crude, hard to control, and caused a lot of dust. What worked best for me was a Dremel tool with the small 1" diamond blades from HF. http://www.harborfreight.com/diamond-rotary-cutting-discs-5-pc-69657.html These cause a very fine cut so not a lot of dust and are easy to control. Just plan on changing the disk reasonably frequently. I think I've gone through about 5 of the packages of 5. Other builders have also said they had the best results with the Dremel tool.

Sadly, I've killed one dremel on this project already. Apparently a tool which creates dust by design is subject to failure due to dust ingestion. .
 
You can get dremel cutting discs now that click on click of. Have a much stronger centre than just the screw. 👍
 
A good jigsaw does cutoff work with a lot less dust.

BTW gents, the kind comments are appreciated, but I'm just a homebuilder, like you. There are lots of good composite guys here. I'm just a TC who takes the time to explain things on VAF. Truth is, most of the real pros don't have the time. They're in the shop, making a living.
 
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Sadly, I've killed one dremel on this project already. Apparently a tool which creates dust by design is subject to failure due to dust ingestion. .

Same here, Kyle. I quickly learned that my dremel was not up to the task of the cabin top. It killed me, too, as I get attached to dumb things - had that dremel for probably 12-13 years:(
 
My Dremel 4000 has held up well to extensive use on my RV-10, including full trimming of the cabin top and Plexiglas. I do "clean" it out occasionally using an air nozzle on my compressor hose to blow out all of the vent openings.
 
Last night's shop session

... pretty good progress - rough trimmed everything except window openings to the plans dimensions/scribe lines. Used a combination of the HF oscillating carbide blade in my Porter Cable 20V multi-tool and a Bosch grit blade in my jigsaw. Easiest technique was to start the cut lines with the oscillating tool which is a little easier to steer precisely, and finish by running the jigsaw through the shallow kerf - the jigsaw blade lost its initial sharpness early on, and seemed to 'appreciate' the pre-cut groove to follow through the thicker flanges. I didn't bother with either a face dust mask or holding a vacuum hose near the tool, as the dust from both tools settles quickly to the floor. Very different from the cutoff wheel.

I found that the factory cut lines yield a doorway section that is 37-1/2"wide, to fit inside a fuselage rough opening of 37-1/8" width. Clearly there will not be much material left in the vertical sides of the fiberglass doorway area by the time I am finished narrowing them to 37-1/8" OD with a belt sander. Pictures of other builds seem to indicate this is pretty standard.
 
A good jigsaw does cutoff work with a lot less dust.

BTW gents, the kind comments are appreciated, but I'm just a homebuilder, like you. There are lots of good composite guys here. I'm just a TC who takes the time to explain things on VAF. Truth is, most of the real pros don't have the time. They're in the shop, making a living.

Well, I am just one of many I'm sure, who thank you for taking the time to explain, I have learned a lot from your comments on here regarding FG and many other subjects. Thanks!
 
Doorway Material Left

...

I found that the factory cut lines yield a doorway section that is 37-1/2"wide, to fit inside a fuselage rough opening of 37-1/8" width. Clearly there will not be much material left in the vertical sides of the fiberglass doorway area by the time I am finished . . .

I found the same thing - had to remove so much material to get the cabin top to fit that I became concerned and called Van's Builder Support. They confirmed that there will not be much material left, and that the scribe lines are wide of what you eventually need.
 
abrasive followup

As promised, a bit of followup on my experience thus far with abrasives and the cabin top. The carbide cutter in the oscillating tool is the most controllable and works well in the thinner parts such as the window cutout flanges. It also makes a nice pilot groove to follow with the jigsaw carbide grit blade. But the tool that comes closest to "like butter" cutting action on the thicker parts is this one -

http://www.harborfreight.com/media/...ab33525d08d6e5fb8d27136e95/i/m/image_8090.jpg

Note that it is more of a shaping tool than a cutting tool (unless you want an inch wide kerf), and it throws dust everywhere unlike the other blades I mention above that merely dribble fine powder at your feet. I ended up using all three to good effect.
 
Free replacement

Sadly, I've killed one dremel on this project already. Apparently a tool which creates dust by design is subject to failure due to dust ingestion. .


One little known fact is that if you return the Dremel they will replace it at no charge

Gary Specketer
 
followup question

A few notes...

Go to Harbor Freight and grab a cheap 6" orbital sander:

http://www.harborfreight.com/6-in-random-orbit-air-sander-63178.html

I think I know some likely answers, but I'm curious why the pneumatic version of this tool is considered preferable to an electric one (half the cost of even the Hazard Fraught model, at WalMart). And is 6" that much better for our purposes than 5", which seems to be commonplace.

Thanks. Getting close to glassing this bird. :) Everything came in my Spruce East order last week except CaboSil and one yard of a two-yard fabric order (what if I'd needed 72" continuous length?), which they backordered to the West warehouse, still hasn't arrived, and is going to cost more in freight than the order itself. But that's a song for another time.
 
...I'm curious why the pneumatic version of this tool is considered preferable to an electric one

Wet sanding, notably cutting paint prior to buffing.

And is 6" that much better for our purposes than 5", which seems to be commonplace.

Nothing wrong with 5", but first see what PSA rolls are on the shelf at your local paint and body supply house. That's where you'll go for a restock on Friday if you want to work over the weekend.
 
Three Stooges

You mean it's bad to mix water and electricity in the workshop? What could go wrong? I've got stinkin' GFCI's _everywhere_.

:p


Great point about the Friday afternoon resupply. Apparently you've been there.
 
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