Well I have come to a small dilemma that I would like to get some clarification on before I progress any further. First off let me say I am using PCL products, I won't be changing that, so I am looking for help with their products only.

Now that I have said that, I was given some of their POLYPRIMER Polyester Primer Surfacer. Now I was under the impression that I could use this direct to bare metal, which I found out that I was wrong later on. Luckily I have not sprayed my car with color yet, but the engine bay did get primed, and there are rust spots coming through the primer.

I will be removing the primer and redoing it again, that's not an issue for me. Now my question is, after reading their info on the product (item #901 for those who care), it states to use their 180 series PRE TREATMENT Coating for optimum adhesion. This is where I am somewhat confused, because they make it seem like it will work when applied to bare metal, but from what I see on my car, and other things I have read, it clearly will not. SO, if I do the bare metal treatment, will this act as a base layer of primer, or what exactly is it? I'm somewhat confused on it, as well as is it able to be sprayed over filler (I'm using Rage Gold).

Thanks for any help in advance!

 

Often time "pre-treatments" or "wash primers" are an acid that etch the metal and create micro-keys to allow the primer to adhere.

While some primers ARE DTM (direct to metal), many are NOT for areas larger than a dollar bill.

Now you say you think that you think the primer is failing because you see rust spots... Did you try to prime OVER rust? If so, that is not proper and THAT is why you are seeing rust spots. Rust needs to be COMPLETELY removed prior to being coated or it WILL eat through. Or (if as I suspect) the rust spots are due to chips coming off the surface and allowing rust in, and in this case, a layer is needed between metal and poly.

While etch primers will work, I prefer 2 part epoxy primers. Either will work.

 

I see what you are saying. I'm still learning about all this stuff. I will tell you what I have read from the PCL product stuff. The Pre Treatment they have is a 2 part coating, so this is the reason I am confused, do I need another primer over this that adheres to metal, or is this in itself what I need below the Polyester Primer Surfacer?

I did not prime over any rust at all, I stripped my bay, did a bit of filling here and there, and primed it. This was done months ago and has been sitting with a few rainy days recently, and there are now rust spots.

I see, in that case, can you point me in the right direction with their coatings so I can get on the ball?

http://www.pclautomotive.com/catalog.html

Thanks for your help!

 

Some say poly primer is "porous" and should be coated quickly or it may trap water and cause surface rust, but I'm not sure how much stock I put in that notion. It seems odd that rust began where there was none before. If you can share how you prep, I might be able to help you.

And yeah, that "pre-treatment" they have is basically an etch primer, designed to improve adhesion. If the price is similar on the etch and their epoxy, I'd go with epoxy.

 

Gotcha, as far as prep goes, I had first hit it with aircraft stripper, and then hit it with a sanding disk on my angle air grinder. Once that was done, I laid down my filler/glaze in a few small areas, and primed it.

So if I do the epoxy, that will be my base primer, and then use my Polyester Primer Surfacer on that after?

I swear paint itself is so much easier than all the primers that there are! lolz

 

I used PCL DTM my when I painted spare tire well. It seems to have worked ok so far. Stuff is nasty though, you don't want to inhale any of it.

 

Hmm, after reading that data sheet, that actually sounds better than what I picked up which is what I was recommended by a friend. I may have to talk to my supplier if he is now only doing waterborne paint due to the laws since that primer works with both solventborne and waterborne basecoats as I am still undecided if I am going to do my bay a different color than the exterior and I had already purchased the bay solventborne paint a good while back... LAGGING on this paint project for real!

Thanks for the input, that was super helpful!