Technical 2 k acrylic eurathane top coat directly over etch primer ?

could use some painting primer advice getting organized and ready to finish the undercarriage paint
after some research decided on eastwood 2K satin chassis black which is a 1 stage acrylic eurathane top coat
the undercarriage had no rust and was lightly blasted stripped to bare metal including the few areas that had rubber undercoating
once bare and clean it was then etch primed.
eastwood does state that this chassis 2k product can go on direct over self etch primer. Has anyone done that without issues
or will it need to have a eurathane primer surfacer applied over the etch then the 2k chassis top coat paint.
its underbody floor pans unibody frame ect so no filller or bodywork
being done.

 

"eastwood does state that this chassis 2k product can go on direct over self etch prime"

I think you answered your own question why would you doubt Eastwood?

 

Scuff it and shoot it!

 

the reason i question the tech from eastwood stating that its ok to apply 2k chassis black direct over etch is due to the many other places and tech sheets that state etch must have another type of primer applied before top coat ?
there seems to be some conflicting information on etch primers ability to be top coated over or not !
the etch primer on my car is not eastwood brand it was applied at the body shop the outside areas of the car had a different primer. but they used self etch under the dash inside the trunk and all of the undercarriage
all the areas where there was no bodywork being done.

 

What he said Scuff what you can with a red scotchbrite pad and sling some paint. That chassis paint will hang on pretty tight. I don't sand my concrete floor and that shit stays on there forever lmao!

 

The only tech sheet and information that is relevant is the tech sheet on the product you are using. Everything else is meaningless. If Eastwood is giving conflicting information then you need to call them.

 

I would put down a compatible primer just to be safe. Just me I guess. Like u-pol high 5.

 

I would doubt them. I bought some high$ ceramic engine paint claimed as Chrysler turquoise, stuff dried Green! looks nothing like mopar turquoise.

 

Usually primer means just that. It's a primer for topcoating. My sandblaster puts a primer on after blasting and I've always applied topcoat straight on or occasionally some hi-fill primer if the surface is pitted.

 

On September 1 I put together a salt fog chamber. I then put transtar self etching primer three coats on a Q panel. On another panel three coats is SpI Epoxy ,next panel three coats rustoleum rusty metal primer, next panel fluid film. I put my own primer on another panel along with the MC inner panel protector which is like fluid film.

On day three the self etch primer was starting rust. I couldn't believe it so I coated another panel again with three coats. After five days in the tank it's rusting again. I would definitely suggest another primer over the self etching primer.

 

Primer will absorb moisture, that's why I cringe when people say they are leaving their car in primer while driving it for a few years. That is only my opinion.

 

That's why I use epoxy primer. No issues in humid Florida.

 

To the OP I have to ask, when you say etch primer... are you using a good 2k etch, or some crap out of an aerosol spray can? I have a friend that sand blasted his 32 Ford at home, then covered it with 1k aerosol etch primer. Did some body work and then applied Trastar 2k primer surfacer. When I sanded it to paint it was covered in rust and the "etch" was peeling off. Be very careful. I would hate for you to have to do this a second time.

Second is less a question and more of a statement, most all paint companies I know of do not recommend etch over sand blast, you are supposed to epoxy. The reason, etch is generally a very thin product and will not "fill" the profile of a sand blast, and even if it did it will settle into the valley of the profile and pool. At that pint it is over applied and will peel off.

 

I agree. Always best bet to throw down a coat or two of epoxy primer. Then you don't have to worry.

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thanks guys for weighing in with some comments
the body was blasted with mostly walnut shell and then fine glass in a few areas in the lightly pitted trunk pan
thoroughly cleaned and vacuumed and blown out afterwards then etch primer was body shop applied in a paint booth several years ago.
since then its been stored in shop out of direct sun. the primer bond is excellent no chipping edges where i have brushed against it in a few areas no peeling or delamination or rust underneath i had to clean a area on the interior floor and went back to bare metal and it looked good underneath. plan to re clean lightly 3m scuff pad to remove any oxidation then shoot a compatable 2 k primer over the etch just to be safe and build a bit more and negate the possibility of issues. then top coat paint within the correct primer/paint window. i dont want any surprizes or issues down the road.