stoneenforcer

My Feedback: (23)

My Pyrahna is in need of a new paint job.
The original paint never really bonded very well to the fibereglass and has some flaking. Plus I was never satisfied with the scheme.

Now my questions,
1. Whats the best way to remove the paint delicately?
* I want to avoid any paint remover that may effect the molding seams. ** remember its all fibergass.
* Not so sure about sanding, as I don't wanna cause non uniform surface areas.

Any pointers would be greatly appreciated.
2. Also, is there anyone out there in the central Fl. area who would wanna do an airbrush for some $$$. ?

wolfy888

You must find out what kind of paint was used first. I would find a place on the aircraft that is in a non-critical area, like a flat portion of the wing, and start testing the usual chemicals (lacquer thinner, naptha, mineral spirits, etc.).  Using a piece of an old towel, apply a small amount of each one 'til you find the one that takes the paint off. Wipe gently and quickly, because some of these chemicals can attack the fiberglass resin, particularly acetone and acetone-based chemicals. Some gentle strippers, like stryp-eze, are fairly safe, as long as you don't let it sit on the surface long enough to soften the 'glass. Your easiest option is to scuff-sand the existing paint to break the surface gloss, then wipe clean with denatured alcohol, then spray a light coat of primer and paint the new scheme over that. As long as you keep your coats light, you won't pay too much of a weight penalty. Remember to feather in the areas where flaking occurred, because the reason the paint let go is that the surface was contaminated during the original painting, probably with some form of silicone or oil. Cleanliness is the key word with paint, especially the first coats of primer, so invest in a large container of denatured alcohol. It's a great cleaner because it  evaporates really fast and takes oils and silicones with it, leaving a clean surface for the new material to bond to, and won't attack the 'glass. Good luck to you, and post pics so we can see the results. Sounds like a fun project. Hope this all helps.

Avaiojet

I agree with the above.But, my guess is, lacquer thinner will not affect the fiberglass. Fingernail polish remover could work. Try a spot.

You couldboard the model out to remove the non sticking paint. A quick "apply and pull" with masking tape, could remove some of this paint also.

Fold the sandpaper to get into the panel lines.

You do have your work cut out for you. Time consuming task.

I do airbrush and paint, but won't be in FL, Jupiter actually, till the fall.

Let us know of your progress. Photos?

Charles

myersflyers

My Feedback: (33)

go Citrus

http://www.rcuniverse.com/forum/m_7743015/tm.htm

wolfy888

No offense, Avaiojet, but one of the main components of lacquer thinner is acetone, which will attack POLYESTER based fiberglass. Epoxy based 'glass is a bit less susceptable to acetone, but if you leave it sit too long, it will eventually soften the epoxy. Quick wipes with a saturated cloth are O.K., as long as you give the stuff time to evaporate between wipes. Now none of this means that if you apply acetone to the airframe, that it will instantly turn to mush; just a caution to only wipe on/wipe off and let some time pass between to evaporate the chemical. Same goes for fingernail polish remover, which is (you guessed it) ACETONE. Stinks worse. MEK (methyl ethyl ketone) will probably work faster, come to think of it, but once again it's quick wipes and evaporation time. And yes, it's a big job. Hope to see the progress pics and the finished product. I used to paint A-10's for the USAF, and these were the methods we used even 20 years ago, because the major wing skin structures are an epoxy-glass honeycomb structure; we had to be extremely careful not to compromise the integrity of the skins in high-stress areas like the flaps, airbrakes and ailerons, main gear nacells, engine nacelles and the like. The radar-absorptive paint we used was EPOXY-BASED, and both acetone and MEK just literally ate it up, along with the outer layers of epoxy if we let it sit too long. Got screamed at once for that; an inner Fowler flap panel is $27,600! Mostly we just scuff-sanded and primed over; as I said, you won't pay too much of a weight penalty if you keep your coats light. Wolfy888