Which Primer For Different Areas?

[notamondayfan 44]

Hello!

 

I'm going to start to tackle the rust on the gti, starting at the front and working backwards. The majority of the rust is just surface, which should be quite easy to grind back and clean up.

 

My only confusion is about which type of primer I should be using on different areas? Ie what should be used on old bare metal, new bare metal, areas where the primer will blow over existing paint, etc. The work will be on areas where it isn't immediately seen (engine bay, inner wings, etc, but there is also a small patch on one of the doors, which could do with some attention before it goes beyond repair.

 

Any advice would be great!

 

Thanks,

Dean

[wicked 103 3 Cars]

I'd use epoxy primer.

[DamirGTI 342]

Another vote for epoxy primer .. an good/quality rust converter over the areas which where cleaned off the rust , and epoxy on top .

 

D

[notamondayfan 44]

Thanks for tips!

 

For the rust converter, is this only applicable if you don't take it all the way back to bare metal?

 

Also is epoxy primer suitable for new and welded metal?

 

Thanks,

Dean

[DamirGTI 342]

Rust converter - you can use it in both cases (some say that it "works better" when there's a certain layer of rust still present - i say that's myth !) , say you clean the surface "optically" all the way till the bare metal , it'll still be rust on the surface which wont be visible to the naked eye .

 

Epoxy primer - yes , can use it on fresh and old sections of the metal (it contains rust inhibitors) .. though , i'd protect welded areas with zinc rich primer first (i used to do that as soon as possible , when i finish with the welding and the weld cools down) cos the rust often starts again from the weld itself if not protected properly .

 

D

[mowflow 67]

Can you get epoxy primer in a rattle can?

 

Doing similar jobs to the OP at the moment and am doing the underside with Jotumastic 87 epoxy mastic applied with brushes and rollers as it will get a layer of stonechip or similar over the top. It would be good to get something similar that can be sprayed on the inside floor . A compressor for spraying is out of the question for me so cans are the only option.

[Tom Fenton 1,542]

Everyone has different methods. On anything that has had "surface" rust (no such thing!) then clean back then treat with rust converter. Ku-rust has always worked well for me. Then on anything that is totally bare metal I use an acid etch epoxy primer, this is a 2 part mixture. Reason for etch is that it will chemically bond to the surface, not just coat over the top.

On anything with old paint on, then acid etch isn't great as it can lift the edges, so in that case your normal epoxy primer is OK.

[wicked 103 3 Cars]

Be aware that you don't spray epoxy primer on etch primer or the other way around.