painting over old paint

[tikicarver]

Has anyone painted a plane that was previously painted?

I don't know what the existing paint on it is, was painted a long time ago so not a new product.

I figure there are two options
1- strip it to bare metal, clean and then paint with new paint system of choice
2- scuff the existing paint, clean well , then prime and paint.

I know a lot of people are going to say to strip it to bare metal. But having done that with small parts, I know stripping an entire airplane will be a big messy job.

So i'm really looking for someone that has painted a plane over an old paint job.
What process did you use and what paint system?
Are there primers that will stick well to existing paint?
Any way to figure out what kind of paint is on it now?
thanks

 

[RVDan]

There are plenty of aircraft painted over old paint. You need to consider the increased weight as a factor, as well as the potential for reduced durability of the new paint. The new paint will only hold on as well as the old paint. Consider that you will be doing ( or paying for) a lot of prep sanding and so on and the stripping option looks better and better.

 

[Mel]

We once painted a C-172 that we counted 5 different paint jobs, so Yes, it is done.
We stripped it and saved a lot of weight. Stripping is by far the best plan.

Urethane paints use a "sealer/primer" so as long as the original paint is prepped to remove all "loose" paint then it is definitely doable if you are not concerned about weight.

 

[tikicarver]

how much weight is one layer of paint on a RV-4?

anyone stripped an entire airplane? what did you use?

I did some research on it, sounds like soda blasting is the best way to do it
but you need to find someone in your area that does it.

 

[Mel]

Depending on who painted it, it could be anywhere between 15 and 35 lbs.
My RV-6 paint job weighs 18 lbs. and still looks great after 21 years.

 

[RVDan]

If you decide to use soda blasting, make sure it is someone with experience on aluminum skinned aircraft. The blasting process can destroy thin skins.

 

[tikicarver]

soda blasting doesn't do any damage to the underlying metal.
Maybe you are thinking of sand-blasting or grit blasting, those are different.
Soda blasting is now used by the Airforce because it is environmentally friendly.

 

[paul mosher]

dry ice

There was a dry ice blasting system developed for aircraft. The only thing left behind was the paint. Do not know of availability.

 

[tikicarver]

I found this process, looks interesting
http://www.dustlessblasting.com/videos.html

They use a mixture of ground glass and water. They say it will not warp the material being cleaned because the water keeps the surface cool. They don't talk about stripping aircraft, but they do strip a 18 wheeler trailer with aluminum sides. I send an email asking if they ever used it on a small aircraft. will post what they tell me.