5 replies to this topic

[monkee-face]

im restoring a 79 van... and on the underside of ther car im going to take most of it back to bare metal.

im tied between using etch primer first
or using a zinc primer that i have,,,

ive herd different things about the etch...some saying you don't need it others saying you do ?

the zinc stuff seems pritty good, its really think and gets into all the seams etc ....

any advice / suggestions would be great !

thanks in advance ..

rob:)

[panelbeaterpeter]

You ALWAYS need etch primer on bare metal, no question, anyone who says different is wrong. I think Zinc is more for using as a weld through primer, it has high metal content so doesn't burn away, I don't think it etches though. Tereson is a good make of etch primer in aerosol form, as is upol Acid8. If you've got a spray gun you can get it in tins, mix it 50:50 with the correct activator, that would be supplied with it. Turn out a more economical way of doing it, just remember to apply one very light dusty coat, it doesn't etch otherwise.

[monkee-face]

You ALWAYS need etch primer on bare metal, no question, anyone who says different is wrong. I think Zinc is more for using as a weld through primer, it has high metal content so doesn't burn away, I don't think it etches though. Tereson is a good make of etch primer in aerosol form, as is upol Acid8. If you've got a spray gun you can get it in tins, mix it 50:50 with the correct activator, that would be supplied with it. Turn out a more economical way of doing it, just remember to apply one very light dusty coat, it doesn't etch otherwise.

thanks for that! will defiantly etch it then! .... what does etch actually do and how is it different?

thanks

[panelbeaterpeter]

It etches onto bare metal, basically it grabs onto it like a b@stard and helps any further layers stick. Use normal primer and it will just lay ontop of the metal, etch actually eats into it. But like I said, it only works if you apply a dusty coat, lots of people wack it on thick which defeats the object.

[monkee-face]

It etches onto bare metal, basically it grabs onto it like a b@stard and helps any further layers stick. Use normal primer and it will just lay ontop of the metal, etch actually eats into it. But like I said, it only works if you apply a dusty coat, lots of people wack it on thick which defeats the object.

oh i see.... i did spray some etch that i had on the inner wing to try it and it came out really hard and shiney! ? is that right? surely not....also ive done one sill and what i done was primed the inner sill(with zinc stuff oppps) and then sprayed on underseal in the silll before putting the new one on? do you think thats ok? i reall want this van to last for my lifetime so want to do it properly!

thanks for all your advice!

[panelbeaterpeter]

What you did to the inner sill sounds fine, etch would have been better but only slightly. Etch shouldn't be shiny! like I said put it on dustily, not a full closed coat.