PLEASE HELP. EPOXY PAINT LIFTING!!!

[jsf74]

i started covering the tailfeathers today and noticed the paint lifting in the corner. i used a two part epoxy like i was supposed to so im kind of lost. i sure hope i didnt really skrew up. cannot afford too many mistakes. any ideas???

[Dennis]

First and foremost, let me say that I am not a "real" painter. Since no one else has jumped in, here is my 2 cents. Now, after the disclaimer, I have never heard of anyone using a mastic but after reading about the stuff,,,,,maybe you can. I really don't know about the stuff. I think, however, I would have stuck with something a little more used in aviation, like epibond or something like that.

Having said that, I looked on the web for this product. It is a urethane product which is used on steel and other surfaces. So I guess, in theory, it can be used. I also noted that the cure rate is 2 to 7 days and MEK is used for clean-up. MEK is used in fabric glue. So the glue may have melted the primer if it had not cured. Also there is the possiblility that the mastic is not compatible with the glue no matter how long you wait to apply glue. Test the mastic surface with a direct application of fabric glue. See what happens.

The answer may simply and most likely be that the mastic did not bonded to the metal. So the glue stuck to the mastic allowing it to be lifted up. If you coated the inside of the tube with linseed oil and it seeped out the weld, then nothing will bond with it. Paint or mastic will not stick to oil. Unless it is an oily wrench of course, then all overspray will stick to it.

As I suggested, take a metal sample, clean very well and coat with your mastic. Wait a couple of days and apply glue directly to the mastic. See what happens. If it melts the mastic, you have your answer. If not, then I would be suspicious of the mastic not bonding to the metal because of an oily surface.

Just a few thoughts. Good luck.

Dennis

[jsf74]

that was kind of the answer i was hoping for. i thought for sure this stuff would work and couldnt belive what i saw. i pulled on another section already glued and it didnt lift at all. i was thinking that maybe i just had a section where the paint didnt adhere to the metal well. i'm going to do some testing and see what i come up with. i have a little in the bottom of the paint cup and am gonna put some glue on it and see what happens and go from there.

[bigjim]

Urathane epoxy can take up to week to harden .. Have been there lately myself. Like the guys said clean with laqure thinner or mek before you spray an let dry an then paint you surface . let set for few days an test ,with m.e.k. Ive found there is a reason for bying aircraft prouducts to paint with. m.e.k. will even take off most powder coats unless there epoxy type. BIG JIM WARSAW IN . IF you get in a real bind call ,(574) 372-9805

[jsf74]

i put the parts in the sun to bake and that seemed to fix the problem. not real sure what was going on. the parts have been painted for six weeks.