priming GRP

[impellerhead]

Hi all,

Newbie here so go easy please , I'm in the processing of painting a GRP jet skiI hull and have a question regarding priming. I intend on using 2k paint but have heard the best results are to hit the GRP with a coat of etching primer first. I see UPOL do a can of 1k etching primer, that is easily available and very appropriate as it's only a small area I'm painting. Just wondering if this is a good route to take as I want to get the job right first time and that it won't have a reaction to the 2k paint I want to out over it?

Thanks in advance for your help.

 

[chopolds]

Etch primers are made for extra adhesion to bare metal. Putting it over plastic offers no advantage. I'd use an epoxy primer, as they have great adhesion over most surfaces, including fiberglass and most plastics, and seal very well, if going over an existing paint or gelcoat.

 

[JT Airbrush]

If the GRP has a gelcoat finish, wipe it down with acetone first to remove any mold release. This is very important as most fiberglass parts are made in a mold, to which a mold release is applied so the part can easily be removed. The mold release typically remains on the surface of the gelcoat. Some fiberglass parts are painted, so you wouldn't want to use acetone in this case. You can test the acetone on a small, inconspicuous area to see if any color comes off on the rag. Acetone will not remove any color when applied over gelcoat. Then just sand well and use a good 2k primer and paint. I don't see any advantage of using etching primer as that is used on bare metal.