Technical Epoxy Priming fresh blasted metal - a discussion.

I have been involved in updating TDS sheets and I can honestly say our focus was much more on ensuring the product works for the customer than it was in covering our ass. We don't want products to fail. It's a pain in the ass and it makes us look bad. The products are heavily tested and information is not put on TDS unless it is thought to be accurate. Now that's not saying things change or mistakes are not made but other than rare instances where something has changed since the original if it's on the TDS there is a good reason for it.

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Its done , the parts are blasted and they used sand. What I cleaned out of the car was tan, red and black.

 

Thanks K13, you certainly add valuable information here.
What product like do you work for?

A little bigger

Some place on the 4 page tech sheet in “fine print” (WHY ?) in an asterisk footnote they said that the testing was done using “bonderite 1000” as a conversion coating.

I read up on the bonderite 1000 - an iron phosphate conversion coating that’s a multi step process that requires plenty of water and last step is deionized water.

 

I'm not familiar with that primer, but from the sheet it appears to be an industrial type primer and not automotive specific? Have you used it with automotive topcoats?

 

Try SPI epoxy primer. You'll never go back.

 

Glad I can be of some help. I work for Evercoat.

I do see that the TDS does state that the surface can be abraded as well so you could have sanded but it doesn't specify a grit but that is water under the bridge now that they are all blasted.

I believe (not positive though as we don't do epoxies) that the testing is done on Bonderite 1000 panels to meet certain ASTM standards. Perhaps aeronautical certifications.

 

Yes,
I love the way the stuff works, sprays, covers, fills, sands the re coat windows.
It’s stocked at a few local paint jobber supply houses,,, but not all of them.

 

actually the tech sheet says to prep using SSPC -SPC-2 and 3 which I sanding/brushing/blasting etc.....

 

Right,,
For best performance a sssp-sp6 (which is 66 -2/3% of any 3x3” area is clean) This came back near white. And the sp6 says visually without Magnification it’s free of crud and debris.
Sooo I read that as blast it just a little better than half assed blow it off till it stops making a mess and shoot it.
More than likely I’m Wrong on that but it seems stupid to blast it, then sand it, then prime it. I could have just sanded it a little bit more and skip the blasting since There’s sanding anyways. That’s a lot of ass ache to get it there to the blaster ,,,, right ? Get the body off the frame, on the cart, cart on the trailer, traveling across town with assholes, off the trailer, worry the blaster don’t fuck it up then repeat the process back to the shop l. Did I mention there was another car body on the cart so we had the fart around and move That car first.... that is whole process by itself.

Lots of labor, risk and exposure to get a blasted surface that’s sanded.

The CRE primer sands really nice plus it’s a great filler . So if there’s some shit in it (there will be) it sands right out with a quick block down for second coat. That second coat to fill the rust pits they blasted out right.

Man I know it doesn’t have to be easy but making it harder and take longer doesn’t work in this case. Especially if there’s no reward.

 

32 Vicki, I love your contributions to this web page, thanks very much.

 

for me, blasting is a paint removal process, not a paint/primer prep process
after blasting, I will DA with 80 and yep some of the detail areas are tedious

 

So whats the advantage of blasting then sanding? Just to smooth it so you can wipe it down?
The sanding is decreasing the etch, or "tooth" compared to the freshly blasted surface...

 

how much tooth does it need
plus the roughness does effect the cleaning of it
I will sand the sheetmetal parts, the frame is usually painted as blasted unless it has pitting issues
to me being clean is just as important as having a tooth
sandblasted means blasted, not clean

 

This photograph of this fender is what scares me the most. Check out this data sheet. After I metal prep the car I seal the whole car with 2 coats of this primer. Then I do the bodywork. After bodywork is done I seal it again with this primer. Then I prime it with a sandable urethane or epoxy primer. As far as using industrial primers on cars it's done every day. Rust doesn't know where it is. I've done it this way for almost 30 years and never have things come back. The Chevy in the avatar was done in 2006 and there's nothing coming through anywhere. Do you know that in industrial applications where they want maximum corrosion resistance this is the type of system they use and these projects usually have a 20to 30 year service life outdoors.

 

I put every single bare metal object, be it out of a box, or fresh from the sandblaster, into epoxy sealer, after sanding it with 80-grit. That way, I get the same exact successful results, every single time.

 

Zinc phosphate epoxy is your standard paint job and works very well. After a period of time zinc phosphate is sacrificial and there's a possibility that corrosion could occur.. I look for coatings that carry me further, maybe for the next guy.