Dumb painting mistake

N282RV · #1 11-28-2006, 11:16 AM

I have started painting my interior and am using the sherwin williams self etching primer for most of my aircraft. This has been applied during the construction process and it provides a nice hard finish, similar to the QB wash primers I think. I went to the SW store and asked them what paints go well with the primer Im using, a few came up and I decided on a water based light industrial enamel designed for marine and industrial uses. I figured that would suffice for my interior. So far so good.
Heres the problem. I proceeded to paint parts and then my cockpit it self. I then did some masking ,after the first color cured for a few weeks, for a two tone look and when I removed the tape, after only a few hours of being on, the blue painters tape pulled up the other paint!!!!!!!!!!!!!!!!!!!!!!!

I believe my mistake was not prepping the primer and thinking I didnt need to. So now what to do, it seems almost impossible to strip the cockpit as it was hard enough to paint with a gun. And then the prospects of stripper getting into rivets and seams and possibly corrosion down the road. The other prospects are that my interior will always have this chipping paint problem. By far this is the most disappointing part of my build experience.
Suggestions? Ideas?
I know alot of parts will not be seen much and or covered with other things but the visible places concern me most.
back to work,

Todd · #2 11-28-2006, 11:58 AM

How about a little sand blasting gun? I believe harbor freight sells them cheap. It'll remove that primer like nothing!

briand · #3 11-28-2006, 12:03 PM

Whats the part # of the primer?
A lot of primers need to be overcoated within a limited amount of time or the top coat will not adhere properly.

Jamie · #4 11-28-2006, 12:28 PM

N282RV:

I painted my interior using the GBP-988 primer and the SW AcrylD over it. The plane hasn't flown yet but the paint is holding up very well to all my bumps and scraping while finishing the build. Don't know exactly what your specific problem is, but at least for me it isn't a problem. I didn't do anything special to the primer before spraying the paint either.

Oh yeah...how 'bout editing your signature so we'll know who we're talking to?

szicree · #5 11-28-2006, 02:08 PM

DO NOT sandblast your airplane parts! Sandblasting can stretch the heck out of metal very quickly.

atreff · #6 11-28-2006, 02:22 PM

According to my research, wash primers eliminate the conversion coat step with acid etch/alodine. Like alodine, the wash primer needs a primer applied over it before topcoat or it will be lifted by the drying topcoat.

For my interior, I went over my S&W wash primer with Epibond epoxy primer followed by the PPG Polyurethane paint.

LettersFromFlyoverCountry · #7 11-28-2006, 02:57 PM

I had this problem on one part. The right arm-rest. The problem is, I can't remember which primer I used. Some of the parts I used the SW primer but other parts I just used the rattle can NAPA (you know, after awhile, it's a total pain in the neck to mix up the SW, get the gun out, paint, and then clean up that mess...that's why I've become a rattle can fan).

I'm using the Rustoleum hammered finish (good stuff, hides fingerprints and surface defects nicely)

But I had taped some paper on it with that blue painters tape and, yep, it pulled off the paint. Funny thing is I took to it with MEK and I couldn't get much paint off and then I sanded it. Ditto. This weekend, I just repainted. Heck, it's going to have upholstery on it anyway.

I've tried the "blue tape" test on a couple of other parts and it didn't pull off the paint....testing it on pieces with SW and pieces with NAPA.

I'm beginning to think maybe the problem isn't with the primer; it's with the preparation on that part before the primer.

sf3543 · #8 11-28-2006, 03:01 PM

I once used blue tape to mask off some cabinetry and when I took off the tape, the varnish came off with it. The painter told me not to use blue tape because it has a chemical in it that eats into some paints & varnishes. (It does have a faint ammonia smell to it.) He said plain old masking tape would have worked better.
Any way, I think I would just sand the edges smooth, prime and repaint the panels where you had the problem and leave it at that. You might be able to get by using a Prevail sprayer if the areas are small enough and just hold a piece of cardboard up against the edge, rather than taping.
Do small areas (one or two panels) at a time, allowing them to dry before moving on to other areas and it will be easier.

I used PPG Concept for my interior and have used blue tape and masking tape on it with no problems, but it is an acrylic enamel and is as hard as nails.

Todd · #9 11-28-2006, 03:58 PM

Quote:

Originally Posted by szicree

DO NOT sandblast your airplane parts! Sandblasting can stretch the heck out of metal very quickly.

I've beadblasted many aluminum airplane parts down to around .020 and have never had a problem with it deforming the metal. I keep the air pressure at a reasonable level and have no problems.

N282RV · #10 11-28-2006, 04:29 PM

Ok home from work now and more specificly I have used this
SW Industrial primer P60 G 2 (recomended in vans manual)
and top coated with
SW DTM(direct to metal) Acrylic B66 W 213
I suppose the paint guys at the store may not be paint guys and I needed to prime my primer then top coat.
I went and looked at my project again and maybe Im overreacting, you all know how it is, have a problem during your after work session and you cant help but think about it all day and how horrible your project is compared to every one elses perfect airplanes.

I will try and use regular masking tape next time.
I suppose if it gets to bad in the future I will have to come up with some fabric panels or something.
I think I have fixed my signature block for you know. Had to figure that one out.