The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Paint & Bodywork

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-05-2017, 09:14 PM   #1
Alex V.
Registered User
 
Alex V.'s Avatar
 
Join Date: Mar 2013
Location: Campbellsville, KY
Posts: 727
How hard is it to prevent this?

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.





__________________
Alex V.
------
1967 C10 Suburban, 350/NP435, Green/Green, PS, PB, HD cooling, charging, shocks, and springs.

1985 GMC C3500 SRW, Sierra Classic, 454/TH400, white/blue.
Alex V. is offline   Reply With Quote
Old 03-05-2017, 11:05 PM   #2
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: How hard is it to prevent this?

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.
Attached Images
     
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 03-06-2017, 01:23 AM   #3
Foot Stomper
Senior Member
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 715
Re: How hard is it to prevent this?

one other thing... what was thr epixy you "spcified" and why that one in particular?
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 03-06-2017, 03:23 AM   #4
Alex V.
Registered User
 
Alex V.'s Avatar
 
Join Date: Mar 2013
Location: Campbellsville, KY
Posts: 727
Re: How hard is it to prevent this?

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.
__________________
Alex V.
------
1967 C10 Suburban, 350/NP435, Green/Green, PS, PB, HD cooling, charging, shocks, and springs.

1985 GMC C3500 SRW, Sierra Classic, 454/TH400, white/blue.
Alex V. is offline   Reply With Quote
Old 03-06-2017, 10:32 AM   #5
MARTINSR
Registered User
 
MARTINSR's Avatar
 
Join Date: Dec 2000
Location: San Francisco Bay area Ca USA
Posts: 2,877
Re: How hard is it to prevent this?

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
__________________
1948 Chevy pickup
Chopped, Sectioned, 1953 Corvette 235 powered. Once was even 401 Buick mid engined with the carburetor right between the seats!
Bought with paper route money in 1973 when I was 15.

"Fan of most anything that moves human beings"
MARTINSR is offline   Reply With Quote
Old 03-06-2017, 11:15 AM   #6
MP&C
Registered User
 
MP&C's Avatar
 
Join Date: Jan 2013
Location: Leonardtown, MD
Posts: 1,030
Re: How hard is it to prevent this?

Quote:
Originally Posted by Alex V. View Post
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..
__________________
Robert
MP&C is offline   Reply With Quote
Old 03-07-2017, 10:55 AM   #7
Alex V.
Registered User
 
Alex V.'s Avatar
 
Join Date: Mar 2013
Location: Campbellsville, KY
Posts: 727
Re: How hard is it to prevent this?

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.
__________________
Alex V.
------
1967 C10 Suburban, 350/NP435, Green/Green, PS, PB, HD cooling, charging, shocks, and springs.

1985 GMC C3500 SRW, Sierra Classic, 454/TH400, white/blue.
Alex V. is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:35 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 1997-2013 67-72chevytrucks.com