Frosting on the Wedding Cake

I've finally stopped un-modifying the cowl in an attempt to get it back to what it was before the Subaru adventure. The exit area is near where it was, 16x5 vrs 14x3.5, but still a bit larger than the standard Van's cowl. I decided to leave it that way because cooling has been just excellent. The Bonanza side cowl vents are staying also as they were a lot of work and do provide some exit area and since they have been around about 50 years on that venerable airplane, may be worth having.

The front of the cowl is also redone to accommodate the AFP ram valve with a 4" James ring intake and the filtered bypass duct drawing air from the left intake area as per Van's. The net result is the bottom cowl is about 50% raw fiber glass and needs filling, finishing, priming and painting. That's where the Frosting on the Wedding Cake comes in.

I am using West fast cure epoxy and glass micro balloons to fill the weave and transition areas that need filling. The first application goes on like frosting on a cake, in this case a wedding cake since we are all married to our airplanes. The old rule of thumb, mix the micro in until it stands up like frosting is just about right.

It started 4 days ago. First sand down was with 50 grit paper, the second with 80 grit, the third with 120 grit and then another fill today as there always seems to be another low spot or hole that was missed earlier. Tomorrow it may be ready for the first of a couple shots of primer which will be hit with wet paper at 220 and then 320 for the paint top coat.

I am a long way from being an expert painter but I will get this done and it will look a lot better than it did. The further away you get from the first 50 grit sand down the more fun and less dusty it becomes. It is a monster job to contemplate but once you get into it, it isn't all that bad.

You remind me of my buddy, David..

...who also had the Subaru "experience" and now enjoys the Lyc and the six round holes on the top rear cowl as a reminder of bygone days.

The old saying "Old too soon, smart too late", eh?

Regards,

Engine conversion

A friend of mine advised me long ago that If you want to do an engine conversion, Convert a lot of Greenbacks to a Lyc. You will be happier than converting an auto engine.

Gary Specketer

Bad day good day....

Well its been 14 days since I began this 10 day job and I finally shot the first cup of paint today. The process started with micro, West glue and 50 grit sand paper, it was a dream to think the airplane would be flying again 4 days ago. It wasn't even close.

And it is not because I've been slacking off. I have filled and sanded every day finally reaching the 220-320 level of smoothness 2 days ago. That precipitated the first attempt to spray primer with an admittedly less than adequate gun and my little compressor. A friend loaned the gun to me, this being a low budget project, and it laid on the primer but not well because the 1.4 nozzle was not right for such thick stuff. That always results in more work getting the stuff smoothed down for the next level as there was considerable orange pealing. The gun is a small gravity feed ATD 6860. I think they quit making it in 2000 as that is the date on the parts sheet.

I've been anxious to know if the actual painting should be turned over to someone who knows what they are doing or move forward on my own so a plan was implemented today. I have both pieces of the cowl about ready to go and also the gear leg struts which had been beat up and were fuel stained from a leaking sump drain, the nose wheel cover which had been all beat up from grass and the prop spinner which had never been painted. It was decided to try real paint on the smaller parts to see how things would go with regard to bugs, dust, and general spraying with my little 2 HP pan cake compressor and the gun of relatively unknown origin, it is not listed with ATD anymore.

The first thing I had to do was measure and mix the 3 part Nason epoxy paint. I have measuring cups so that is not too big a deal once you scope out the ratios - 8 parts of this, 2 parts of that and finally 1 part of something else. That's when the bad of the day ensued, I had the quart of paint in one hand and was holding the cup in the other trying to very carefully pour 8 ounces and after the 8 were poured was setting the quart can down when it slipped out of my hand and dropped about 4 inches to the table top. It did not tip over and spill but did hit rather hard and a goodly amount of the very expensive stuff flew up and all over my left arm and on the floor. Not a good start at all, I thought, but called a halt to the mixing process the clean up the mess.

About 15 minutes later the other 2 parts were mixed in the concoction and it was strained into the gravity feed cup of the little gun of unknown origin. I learned somewhat how to adjust the air and fluid flow spraying primer so as not to have too much stuff coming out and not have it too dry. This was accomplished spraying onto a large card board box. Then it was on to the little parts I had stuck on sticks and clamped up right.

Much to my delight and surprise the little gun of unknown origin did a great job with real paint that was loose and not thick like primer. The first parts had a couple runs but I quickly learned to back off a bit with the fluid flow and move the gun a bit quicker. The paint flowed out beautifully and ended up very shiny. And no bugs or dust on the finish! What a deal.

I say all this so those of you contemplating painting your own airplane can be assured you can do it. If I can do it, anyone can. Begin with the little stuff and make the mistakes there. The rest of the airplane will be ok although it will take some planning to not get over loaded trying to do the whole thing in one day. And use good paint. The stuff is expensive but will provide a much better end job than going cheap with tractor paint.

Way to go, David...

....it reminds me of my learning before I painted my first 427 Shelby Cobra replica....all my trash drums got painted, my garage doors (inside) and my engine hoist....if it stood still, it got painted so I told my wife to keep moving, or else....also with a cheapo NAPA gun.

Good luck,

There is a common misconception here. Good paint guns don't have to cost a lot of money. Sure you can get a good paint job with a gun from the Harbor but you can have a pretty descent DeVilbiss gun for less than your weekly UPS bill during the last few weeks before your Airworthiness Inspection. Go ahead and treat yourself to one more good tool. But be forewarned, The more 50 gallon drums you paint the better your airplane will come out.

Painted with a $120 DeVilbiss FinishLine gun

Primer?

David - did you reduce the primer? Most non-epoxy primers need to be reduced by 1/2 with the appropriate thinner. You can take some liberties and adjust the viscosity to your liking. I always put the first coats on a little heavier, finishing with very thin coats for less sanding.

Spray gun 101 tips

David,

I've painted a couple of cars and am currently painting my RV-6A. From your post, it looks like you could make use of the info from the links below. They give some helpful advice on setting up the gun.

Good luck!

http://www.stovebolt.com/techtips/hvlp_paintgun_basics.pdf
http://www.autobodypro.com/tektips/articles/spray_guns.htm

MNForrest said:

David - did you reduce the primer? Most non-epoxy primers need to be reduced by 1/2 with the appropriate thinner. You can take some liberties and adjust the viscosity to your liking. I always put the first coats on a little heavier, finishing with very thin coats for less sanding.

Click to expand...

Thanks. The primer is Nason 2K Urethane with an activator, epoxy I think.

trib said:

David,

I've painted a couple of cars and am currently painting my RV-6A. From your post, it looks like you could make use of the info from the links below. They give some helpful advice on setting up the gun.

Good luck!

http://www.stovebolt.com/techtips/hvlp_paintgun_basics.pdf
http://www.autobodypro.com/tektips/articles/spray_guns.htm

Click to expand...

Thanks, I will take all the help I can get.

Just curious what you did with your Subaru engine and prop. I too made the automobile engine mistake (Subaru) on my 6A. It will eventually be replaced with a Lycoming, but not until I finish my 7A. I hope others reading this will learn from our mistakes and use an engine designed for an aircraft.

Jay Erickson, 6A complete, 7A finishing kit
Roseburg, OR

If this was the primer...

MNForrest said:

David - did you reduce the primer? Most non-epoxy primers need to be reduced by 1/2 with the appropriate thinner. You can take some liberties and adjust the viscosity to your liking. I always put the first coats on a little heavier, finishing with very thin coats for less sanding.

Click to expand...

...David was using, no reducer involved...

And I'm pretty sure it's not an epoxy -

http://pc.dupont.com/dpc/en/US/html/visitor/common/pdfs/b/product/nsn/Nason/NAS_421-21_TDS.pdf

Wolf said:

Just curious what you did with your Subaru engine and prop. I too made the automobile engine mistake (Subaru) on my 6A. It will eventually be replaced with a Lycoming, but not until I finish my 7A. I hope others reading this will learn from our mistakes and use an engine designed for an aircraft.

Jay Erickson, 6A complete, 7A finishing kit
Roseburg, OR

Click to expand...

Hi Jay,

Yea, I've switched back to Lycoming. I had over heated the H6 and thought the engine was cooked, lost confidence in it. The over heat occurred because the MT prop brush blocks dropped off the rail with the blades in fine pitch.

The prop went to Andy Plunket, a GlasAir Subby guy in Oregon. He is using it with his 2.5 engine and a Marcotti PSRU. The engine I gave to Rod Schneider in Atlanta. He took it apart and could find no damage due to the over heat. Had I known that, I would have stuck with the beast, warts and all, as it cost a lot of money to go Lycoming. But when I made the decision, it seemed like I should make the change or quit flying.

Life goes on - I shot the cowl yesterday and except for a couple runs it looks great. Painting is a learning process, the first coat went on fine, very thin, but I over did it with the second and got a little too much paint on in two areas. The runs I can fix with fine sandpaper and a buffer after a few days of cure.

I am pleased with the results of this effort. I looks a lot better than it did. If I can relocate my lost camera, I will post a picture of it.

az_gila said:

...David was using, no reducer involved...

And I'm pretty sure it's not an epoxy -

http://pc.dupont.com/dpc/en/US/html/visitor/common/pdfs/b/product/nsn/Nason/NAS_421-21_TDS.pdf

Click to expand...

Yep, that's the stuff. And they recommend a 1.7 - 1.8 nozzle. What I have is 1.4 and that's the problem although I shot some on the top cowl yesterday and it went on fine. I just gave it more juice and more air.

Sand runs and repaint right away

David,

I've just started painting my 6A and agree on the learning process thing. I've shot a couple of cars in the past, but it's been awhile. I'm using a single stage polyurethane primer and paint. I shot the rudder and elevators as the first batch, and everything looked good, but just a touch of orange peel. I took it to a painter friend and he gave the thumbs up. On the next group, flaps and ailerons, I tried a bit heavier coat to eliminate any orange peel. It does look flatter, but I got a couple of runs. The tech sheet says you can sand after drying (2 hrs) and respray. After 36 hrs everything has to be sanded again to spray (320 grit). So, the day after initial spray (24 hrs), I sanded the runs and sags with 320 until everything was faired in and resprayed. Next morning you can't tell there was ever any issues

So.... I'd recommend if you get any runs, wait until the next day and then sand the errors and respray the area you sanded. No need to do the entire part. It hasn't yet fully cured and the results look great. Just clean after sanding and tack off. Everything is already set up from spraying the day before so you save that time.

The paint is dry....

I took much longer than the estimated 10 days, like almost 5 weeks, but the cowl paint job is done. It isn't perfect but it is a lot better than looking at raw fiber glass. It is smooth and it shines.

While everything was apart, the NG was upgraded with the Matco axle and the easy on/off NG pant brackets. The new brackets are .065 thick, the old ones were .040 and one was broken so it was time to make the change. I also installed the intake air flow ramps on the top cowl. I think they are called RV-8 ramps. They were never installed with the Subby.

I flew for 1.1 today with the OAT in the high 80's, cooling is not an issue. But my landings are - I've been off since mid April and will definitely get spun up this week, still having a problem getting this thing to slow down with the FP Catto.

Here's another shot of the taxi way in front of our home.

The horses are not ours but they are always there to look at. We had 3.5" of rain last week so the grass is really growing and the animals are chowing down big time. Every now and then one gets out but so far they have not gone on to the runway which is about 500' straight ahead.

Take off performance was not good today with a soft field, 4" of grass and OAT in the high 80s. It was one time I wished I had the CS MT prop.