How hard is it to prevent this?

[Alex V.]

Last fall I had floors and other panels put in a Jeep CJ7 tub by a restoration shop (all makes) and in less than a week the epoxy 2K primer I specified pulled off of a good portion of the welds on the inside surfaces of the floor, and after one 500 mile trip in the rain (stored inside since) rust stains appeared from around some of the welds and crevices. Am I expecting too much that these flaws shouldn't be there? They were none too neat with the seam sealer, either - I'd thought they did good work but I'm becoming increasingly disappointed with their attention to detail.

[Foot Stomper]

First off, nothing including seam sealer, epoxy primer, paint or even snot won't stick to a dirty, oily surface. You have seams that would indicate a dirty, oily surface... at least where the coating fell off.

Secondly, rust will appear where moisture and oxygen are in the presence of bare steel. If the coating (in this case epoxy?) leaves room for moisture and oxygen, you'll get rust. Even flash rust can be contained by a good epoxy primer.

Good epoxy primer (regardless of brand 100% of the time) is NEVER UV resistant but WILL resist corrosion "creep" after a scratch or bruise... rust will appear in scratch but will NOT creep or spread.

Crappy epoxy coating combined with bad prep will result in rust as you have experienced. Perhaps it's not even epoxy??

These pictures reveal crappy epoxy from ProForm that was exposed outside for 10 days. Total crap... had to sandblast again and recoat with real epoxy.

Take it back to the shop and with a polite presentation, point out your "issues" and ask for a remedy.

[Foot Stomper]

one other thing... what was thr epixy you "spcified" and why that one in particular?

[Alex V.]

Too late now, I have to have the thing together in less than 2 weeks so I'm working with what I have. Mainly wanted to snap pics and get some opinions before I shot some self-etching primer on the bad spots and covered it up with paint. I can't be sure of the brand they used (not sure if it was in the receipt notes) but my specification was a 2K primer appropriate for spraying Nason Fulthane over.

[MARTINSR]

2k primer is any primer with a catalyst, that means urethane, iso-free 2k, epoxy, etc.

I have to tell you, I have had professional painters who paint every day point to an iso-free filler primer with a DTM (Direct To Metal) on the label as "epoxy" when I asked them where the epoxy was that they were shooting. They had no clue what an epoxy was! These are pros that paint every day. Their education was limited to the stuff they worked with, period. Epoxy was outside the box and they were clueless.

Brian

[MP&C]

Originally Posted by Alex V.

Too late now, I have to have the thing together in less than 2 weeks so I'm working with what I have. Mainly wanted to snap pics and get some opinions before I shot some self-etching primer on the bad spots and covered it up with paint. I can't be sure of the brand they used (not sure if it was in the receipt notes) but my specification was a 2K primer appropriate for spraying Nason Fulthane over.

Looks like lack of prep, lack of repair in the case of that one crack. Also looks like things got WET before paint was applied, and again, with lack of prep before painting, for all that rust coming back through. Not sure what primer they used, but if they failed in these other areas, it's hard to say what was used for primer.. regardless of what you asked for..

I'd be cautious about using etch primer in the vicinity of your 2K/epoxy? as the etch may cause the edges to lift/ruffle on you..

[Alex V.]

I'm realizing that, MartinSr - and seeing as how a lot of the people I'm finding to subcontract the work to around here are old, or old-er, timers their "favorite products" range all the way from self-etching primer and lacquer, to red oxide as the best thing to put on a frame, to base-clear and everywhere in between.

MP&C, the self etching primer didn't have any immediate reaction with the areas where it was oversprayed onto the grey stuff and looked fine when I coated over it with equipment enamel 24-36 hrs. later.

FWIW my end finish materials will be Nason Fulthane on the exterior (over whatever this grey primer is) with Rust-Oleum farm/equipment satin black enamel brushed on the inside the tub (gets carpet so I just needed something to cover over the primer) and Transtar 2K epoxy primer on the sandblasted frame with the Rust-Oleum sprayed over that.