Page 1 of 1

Primer

Posted: Mon Aug 16, 2021 1:03 am
by kgfaro
I've seen some posts inn using self etching primer. But I don't plan on going down to bare metal just a over paint any suggestion on what primer to use? High fill reg Rustolium etc?

Re: Primer

Posted: Mon Aug 16, 2021 9:21 am
by JPG
Why would you need a primer for an already painted surface.

Re: Primer

Posted: Mon Aug 16, 2021 9:24 am
by RFGuy
This is what Rustoleum® says with regard to "self etching primer". Seems like it is intended for bare metal application..not that you couldn't use it over paint though if you wanted to, I presume?


Rust-Oleum® Self Etching Primer is designed to prepare bare
metal
, aluminum and fiberglass surfaces to promote maximum
adhesion and smoothness of the topcoat finish. Self Etching
Primer is a rust preventive coating that etches and primes in one
coat. Self Etching Primer features an advanced spray system
that allows you to spray at any angle, even upside down for
those hard to reach areas. A comfort spray tip with a wider finger
pad reduces fatigue caused by continuous spraying.

Re: Primer

Posted: Mon Aug 16, 2021 9:25 am
by kgfaro
Call it a habit plus a good primer will protect against future rust

Re: Primer

Posted: Mon Aug 16, 2021 9:26 am
by kgfaro
RFGuy wrote: Mon Aug 16, 2021 9:24 am This is what Rustoleum® says with regard to "self etching primer". Seems like it is intended for bare metal application.


Rust-Oleum® Self Etching Primer is designed to prepare bare
metal
, aluminum and fiberglass surfaces to promote maximum
adhesion and smoothness of the topcoat finish. Self Etching
Primer is a rust preventive coating that etches and primes in one
coat. Self Etching Primer features an advanced spray system
that allows you to spray at any angle, even upside down for
those hard to reach areas. A comfort spray tip with a wider finger
pad reduces fatigue caused by continuous spraying.
I did mention I'm not going down to bare metal so I won't be using self etching

Re: Primer

Posted: Mon Aug 16, 2021 9:29 am
by kgfaro
JPG wrote: Mon Aug 16, 2021 9:21 am Why would you need a primer for an already painted surface.
Sorry just figured ought how to answer a specific person
I said a good primer protected against future rust.And I may want to change the color. Guess it's just like painting a house lol

Re: Primer

Posted: Mon Aug 16, 2021 9:48 am
by RFGuy
kgfaro wrote: Mon Aug 16, 2021 9:26 am
I did mention I'm not going down to bare metal so I won't be using self etching
Only question I would have is how the adhesion differs in putting self etching primer overtop of existing paint. I mean is the self etching nulled out by putting it on top of existing paint instead of bare metal? In other words you are using a more expensive primer when a simpler one would do. Or could some adverse reaction happen between the self etching chemical and the old paint? If the latter, a plain primer may bond better to the old paint than the self etching primer. I have no experience with self etching primer, so I am just asking the question here wondering how it will bond to old paint?

Re: Primer

Posted: Mon Aug 16, 2021 9:55 am
by kgfaro
RFGuy wrote: Mon Aug 16, 2021 9:48 am
kgfaro wrote: Mon Aug 16, 2021 9:26 am
I did mention I'm not going down to bare metal so I won't be using self etching
Only question I would have is how the adhesion differs in putting self etching primer overtop of existing paint. I mean is the self etching nulled out by putting it on top of existing paint instead of bare metal? In other words you are using a more expensive primer when a simpler one would do. Or could some adverse reaction happen between the self etching chemical and the old paint? If the latter, a plain primer may bond better to the old paint than the self etching primer. I have no experience with self etching primer, so I am just asking the question here wondering how it will bond to old paint?
I've seen it done on pc cases with SEM but I think it's not necessary with the surface on my ss So a reg primer should do like a Rustolium that or use a primer paint combo Rustolium makes that also

Re: Primer

Posted: Mon Aug 16, 2021 1:59 pm
by chapmanruss
Some testing might be in order. Some paint combinations do not work well together. Have you ever seen a 2000 era white painted vehicle with the paint flaking off? There was a problem with those vehicles paint not adhering to the primer due to paint and/or primer formulation changes at the time. It is the same reason Shopsmith sells before and after 10-01-2001 gray paint.

Re: Primer

Posted: Mon Aug 16, 2021 9:59 pm
by kgfaro
chapmanruss wrote: Mon Aug 16, 2021 1:59 pm Some testing might be in order. Some paint combinations do not work well together. Have you ever seen a 2000 era white painted vehicle with the paint flaking off? There was a problem with those vehicles paint not adhering to the primer due to paint and/or primer formulation changes at the time. It is the same reason Shopsmith sells before and after 10-01-2001 gray paint.
Very similar to the 1970s and Chevy we used to call it the
Chevy disease. They where using a latex based paint o.j. A oil primer. Cars looked like they had the pox. Not sure if there was a lawsuit about that too I don't remember