Zzz wrote:

courierguy wrote:J
Am I wrong on what a PITA it was Zane?

Probably not, but I wouldn't know. Mine came painted from the factory

Still, I plan to shoot my touch ups with my HVLP. That will be a pain in the ass with all the masking.

If it would help, you can borrow my air brush. Maybe less overspray concern. Just an option....

I did one complete with a brush, one big fuselage mod with regular paint gun. Both had missing paint spots.

The red cub I built was powder coated. Best thing I did. Engine mount, struts, landing gear, tail feathers, flap handle, doors, cabin heat box, instrument panel, fuselage, +100 small pieces. Flat black, black, textured black and red. All the job for a very good price. No missing paint anywhere.

I'm in a modification process of that red cub right now. That powder coat they use is a PITA to remove, really strong chit.

My new landing gear and suspension setup will be powder coated textured black or so. No hesitation.

That paint I mentioned was MIL-C-22750D epoxy paint. Almost as hard a ceramic coat! (almost)

Oli points out another disadvantage with powder coat on airframes: Makes repairs REALLY difficult. And after any repairs, you'll have to paint over them.

I've never been a fan of powder coated frames. As noted, if corrosion gets started under it, you'll have a tough time finding it. If it's REALLY well done it might be good, but again if you ever need to do repairs or mods, good luck.....the stuff is really hard to get off clean.

MTV

Battson wrote:That paint I mentioned was MIL-C-22750D epoxy paint. Almost as hard a ceramic coat! (almost)

I've got the MIL specs from Mark and he is going to send me the paint color code so I can try to match the color with a local supplier. Trouble is the local guys don't know what a mil spec is so I'll have to identify which paint I want.

Those Boeing spec paints seem really awesome but I bet they are way spendy. Only reason I wouldn't go with the same paint Avipro uses would be if I found a equally good paint that didn't require a supplied air system.

On BH #357 we had the frame and motor mount powder coated in white to show up any missed spots and rust. The process was to sand blast with garnet material then powder coat immediately before the rust bloom starts. I do not remember the powder paint used but it is designed for flexing and works with the fabric glue. It is not good to have the polytone melt the paint. During the build all intersections were cross drilled so we could pressure test for leaks in the welding. We had a couple of leaks that were very hard to find so I pressurized the frame with propane and found the leaks. We then pulled a full vacuum to remove all moisture and filled the frame with dry nitrogen to prevent rust. We installed pressure gauges in the dash and they are part of the flight precheck. The gauges read 10 psi and go up and down as the temperature changes. In 11 years there are no leaks and no signs of rust. I also know that if a repair has to be done at any time the removal of that powder paint is going to bring forth cuss words that even a sailor never used.

whee wrote:

Battson wrote:That paint I mentioned was MIL-C-22750D epoxy paint. Almost as hard a ceramic coat! (almost)

I've got the MIL specs from Mark and he is going to send me the paint color code so I can try to match the color with a local supplier. Trouble is the local guys don't know what a mil spec is so I'll have to identify which paint I want.

Those Boeing spec paints seem really awesome but I bet they are way spendy. Only reason I wouldn't go with the same paint Avipro uses would be if I found a equally good paint that didn't require a supplied air system.

WHee, don't shoot or mix any of it with out supplied air!!, AINT WORTH IT!!

Another kinda dumb question: Can a paint pump be used to apply the paint? Think I'm going to use Stewart's which they say is water cleanup so why not use a pump?

whee wrote:Another kinda dumb question: Can a paint pump be used to apply the paint? Think I'm going to use Stewart's which they say is water cleanup so why not use a pump?

Are you talking about an airless paint system? If so, those are great. Graco makes some nice systems that are totally pump driven.

And this sounds ridiculous, but my Wagner Power Painter works almost good enough for an airplane paint job-- if it was a little more adjustable. You can't quite fine tune it to lay on the ultra thin coats like you can with HVLP.

Yeah, I'm talking airless. Seems like a good way to go if the paint cleanup can be done with water. I'm not half bad with a airless sprayer.

There is a tube and fabric guy in the area that uses airless (a Wagner power roller specifically) for the first coat and his jobs are 100% showroom quality. The water based system I used had a notes section devoted to airless application.

I was privileged to attend one of the aircraft ownership seminars presented by Clyde Smith "The Cub Doctor" one year when I had a J-3. He showed us an old Piper newsreel film of the Piper factory cranking out Cubs a mile a minute in the 1940's.

He made a big point in repeating the section where they dipped the steel tube fuselages in a huge tank of Zinc Chromate primer. Then he said:

"Folks, THIS is why your 50 and 60 year old Cubs and Champs and Taylorcrafts are still out there flying safely. Dipping those fuselages guaranteed that the primer got everywhere. Spraying will not do that. Those of you restoring airplanes who think a beautiful glossy airbrush or HVLP spray finish is the right way to do it are wrong. A perfect historically correct museum restoration fuselage would be covered in drips and runs and blobs of Zinc Chromate."

Someone asked him how you would accomplish this today without a 500 gallon tank of liquid. He said brush the liquid primer on, and shove the primer into all the nooks and crannies until it is dripping and leaking everywhere. Then if you want to paint your fuselage frame do it afterward, but make sure that zinc chromate is squirted and dabbed and poured over everything first.

We know know Zinc Chromate primer is a cancer-causing problem when you inhale the spray. The EPA and CIA and FBI and TSA will probably drag you away in leg irons for spraying it these days. PLUS the wasted paint, PLUS the solvents and paint guns and compressor noise, etc.

So for all those reasons I'd say brush it. Wear a respirator anyway because of the solvent.

Actually, you can't get "zinc chromate" primer that is the same as what they used in the 40's.... and that's not a bad thing. Brushing into the corners is a good thing, but from there he's all wet as far as I'm concerned. The modern epoxy primers are so much superior to the old zinc primers it's not funny.
JH

About the only thing about that stuff that is like the zinc chromate of the 40's is the color.
JH

Ive used it on a lot of little parts, so far, no problems. Whats your experience with it?

John, I'm covering a PA12 right now and used Premier Powder Coating in Rexburg to blast and to prime, then I painted the top coat on the frame. Having them prime the frame allowed me time to make any needed repairs without having to worry about rust staring to form. It saved me a step also and the added cost for the priming was not that great. They did a good job of getting paint into the tube clusters.

Cool, thanks! I'll give them a call tomorrow and talk with them.

FWIW, the FAA really does not like powder coating, for one (valid) reason. It is so good that it will stretch and cover a crack without the crack showing through. So an inspector or owner can be looking right at a cracked weld and not see it.

This concern is valid, but you can make a case either way. On one hand powder coating delivers really good protection, so that some amount of damage and corrosion of the structure will not happen in the first place. On the other hand, if you over-stress an airframe and start a crack, it may never be seen until it fails catastrophically and hurts someone.

So the question might be whether corroded and rotted tubes represent more of a risk (causes a higher number of crashes) than cracked or damaged tubes cause. That might be something for the NTSB and "continued airworthiness for the aging aircraft fleet" people at the FAA could look at figuring out.

Deleat