why/how

[hoss]

why do you start w/ the etching primmer on raw metal, won't a urethane primmer give enought duability? if the urethane primmer is going to chip wouldn't it chip off of the etching primmer just as easy as bare metal?

do you sand the etching primmer and them use the urethane primmer, or just hit it w/ the base coat and go from there?

 

[BDsbigZRX]

..

I've heard conflicting reports on this from even the PPG tech folks. Personally, I never use an etching primer, I go over an 80g scratch on bare steel with PPG's DP primer. Usually, if you do spray an etching primer, you go over it with something like the PPG DP shortly thereafter without any sanding in between the steps.

 

[TAZ]

We usually use SX1031 for bare metal, then go over it with the epoxy primer without sanding the SX1031.

I know there are primers out there that you can use over bare metal without the use of etch priming.

 

[hoss]

Thanx guys. i was just wondering if you sand the epoxy primer. it's some hard stuff!

 

[paintinheli]

hi hoss etch primer bites into the metal they say but i have found that most of the primers nowadays are compatible or bond directly to metal in my line of work i have to etch using a corrosive proof primer hopes this helps just read the tech sheet to make sure the primer is or can be applied directly to metal

 

[crazycuda]

Hi guys hope this helps,
Heres what I learned when I was on my k38/k38 dtm quest lol.
Etching primer has acid in it to burn it's way into the metal. Epoxy on the other hand is less agressive and it really needs 80 grit scratches to get a good metal bond. After either is dry there is no absorbition problems (like epoxy glue). With a 2K primer it is pourous (like bondo) it will absorb water etc even after it had dried. With 2k being used for a metal primer it will work but there is no corosion protection and over time if water can get to it, it will lift off and have rust under neath it.