Hi all:

My paint guy told my to use self etch primer on all bare metal surfaces before I bring him parts to be painted. I have fixed some spots with fiberglass body filler and some other spots with standard plastic body filler. Can I use the self etch over the body filler or will this damage it? I would ask my paint guy, but he is away for a few days and I plan on doing the priming before he gets back into town.
Thanks in advance for the help.

Etch over filler is fine. Some guys like to fill over the etch, which might be slightly better, but spraying etch over bondo will not have any adverse effects. Have done this many times.

Thank you. :)

Sorry to disagree Bob, but it probably makes a difference depending on the product maker.

I do know that PPG says not to put a etch product ot thier's (dx170?) directly over filler. I never would do it without reading the P sheet first.

I would also put primer over bare metal BEFORE body filler because filler acts like a sponge and will over time cause rust to from and bubble up on you. I like a two part epoxy prime.

The norm always used to be fill first, then etch primer, then fill primer,sealer,base,clear. Now its reverted to etch,filler,etc.etc. Both schools of thought are still out there.All I know is that I've done it both ways with several brands and never had any issues. PPG ,Ditzler,and HOK.

Just received new copy of chevy high performance. Title is paint how to. All of the different shops featured in the articles say use filler over metal. It has a diagram on how all the layers should be from the cars sheet metal to the cop coat.

Just follow the P sheet on what ever product you use and it should be fine.

I do understand the "what works" approach too.