Hangar Flying

Hangar Flying => Hangar Flying => Topic started by: 16FW on May 14, 2010, 08:47:53 AM

Title: Paint stripping
Post by: 16FW on May 14, 2010, 08:47:53 AM
Is there a way to strip just the topcoat and leave the primer? I used Blue River water-borne urethane, and it is cracking, ad flaking off. The primer is fine, and showing through in a lot of places. It was a lot of work to fill/sand/fill/prime, as most of you know, and I would hate to do all of that again.

My primer was US paints, and their rep at Oshkosh said their AwlGrip primer is pretty tough, and I could probably find a concoction of chemicals to wash the Blue River junk off. He just didn't say what mixture  ::)

I have been looking at some of the newer, milder, chemical strippers, but none say they can only take off one layer of paint. I have also looked at soda blasting, but i get the idea that it would also take off all the paint.

If it matters, my plane is a Rutan Defiant (hi Harry)
Title: Re: Paint stripping
Post by: LongEZDaveA on May 14, 2010, 10:51:45 AM
I'm sure you already know, but I gotta mention - any stripper or mixture you consider using should be checked to see if it is possible for it to harm the foam.  If there's a way, it will find its' way to the foam and could melt it.

Good luck.
Title: Re: Paint stripping
Post by: 16FW on May 14, 2010, 11:30:55 AM
I'm sure you already know, but I gotta mention - any stripper or mixture you consider using should be checked to see if it is possible for it to harm the foam.  If there's a way, it will find its' way to the foam and could melt it.

Good luck.
Yep I know, but I hadn't thought about that issue. Thanks!
Title: Re: Paint Stripping
Post by: Joe Dubner on May 15, 2010, 06:11:31 AM
Is there a way to strip just the topcoat and leave the primer?

You sould look into sodablasting (http://en.wikipedia.org/wiki/Sodablasting (http://en.wikipedia.org/wiki/Sodablasting)) as the "depth" of the stripping is controllable and the process is compatible with composite construction.  While I don't have any firsthand experience with it, that never stops anyone from posting anything about anything in these forums :-)
Title: Re: Paint stripping
Post by: A. Bruce Hughes on May 15, 2010, 08:45:46 PM
Hi "16FW" whoever you are:

A "concoction of chemicals" is a VERY bad way to go.   At least you MUST
get the MSDS for every chemical.   Pay particular attention to the inhalation
danger and the skin absorption danger.   In the past people have had severely
damaged livers and other organs.   The situation is a little better now with OSHA
providing guidelines for WORKERS in different industries.

If you don't understand what I am saying, "Google" up OSHA + MSDS and read
some.   May save your life.

Another source: RTECS

When I was teaching I once needed to order silica sand (ALL of the local sand was
pulverized limestone which is different from your typical sand).   The box was
delivered with a bottle of sand and a MSDS for silica sand.

I think you should consider Joe Dubner's suggestion.   BTW, you still need a
good facemask, preferably with air flowing to it.

Bruce Hughes    :)
Title: Re: Paint stripping
Post by: 16FW on May 17, 2010, 06:08:11 AM
I had arranged for a soda blast guy to come this past weekend to give me an estimate, but he never showed up.