Primer Compatibility

I have been using a Prekote/ Sherwin Williams 2-part epoxy primer system on my RV-10 thus far. I'm thinking of changing primers to one of the easier rattle can methods (I think SW and Napa both have self-etching rattle can primers). My question is if I change primers in the middle of the project, how will these new primers react to the original 2-part epoxy primer already applied to some parts (especially where the 2 will come into direct contact)??? For example, the HS spars are done with the 2-part epoxy primer. The ribs will be done with the new rattle can primer. Any compatibility problems here??

Anybody got any other ideas??? The 2-part system works but it just takes too much prep and cleanup time.

I know that water based primers have been mentioned. Any thoughts/ideas there???

In your opinion, what is the best/easiest priming method for the most reasonable cost???

I don't want to start a priming war here, just getting some ideas.


TIA,
Bill Britton
RV-10 Emp
Priming HS

Bill,

I am not sure about the interactions, but I would like to warn you a little bit about using the Sherwin Williams GBP988. While it is easy to use, and I still use it on small jobs, it does not etch very well and easily scratches off revealing an almost unchanged alclad surface underneath.

If I may make a suggestion, go to your local auto paint supplier and get some VariPrime. It is a 50/50 mix of primer and converter (phosphoric acid) mixed in the sprayer. Only minimally more time consuming than the rattle cans, but once this stuff is on, it takes a lot to scratch it off and many builders out there swear by the stuff.

Just a thought!

Also check out this thread about Dupont's Variprime system.

http://www.vansairforce.com/community/showthread.php?t=271

-Jim
o=\o

I don't know about best, but this is the easiest. Trust the alclad to do what it was manufactured to do, prevent corrosion. And prime the non-alclad extruded parts with a rattle can.

Personally, I've been using the Sherwin Williams GBP-988 rattle can more and more lately. I agree with Will that it is easy to scratch. I usually Scotch-brite the parts before cleanign and priming. That helps with adhesion. If I scratch the primer, it takes about 2 minutes to touch it up.

Dave