I was reading the PPG datasheet for their filler (which I am using). It says that it can be used over bare metal or epoxy primer, but NOT the primer-surfacer. I've always heard it the other way around?

Well I would trust the Tech Sheet... http://www.chevelles.com/forum/biggrin.gif

Huck,

I would trust the PPG P-sheet.

Once you get to the primer surfacer stage, you shouldn't need filler anymore. I used a small amount of glazing putty in a few areas over PPG NCP271 primer surfacer with no problems. If you have an area that needs filler, spray the DP over the primer surfacer, then use the filler.

Hope this helps,
Jim Endrud
http://members.home.net/jimmy4/elky2.jpg


[This message has been edited by jimmy (edited 05-19-2001).]

There is a difference between etching primer and the "primer - surfacer".... The self etching primer is a paint that has a goal of sticking to steel; it cannot be sanded easily and does not fill low spots. The SURFACER is the stuff that is sandable and can do some serious filling of low spots. So, putting the etching primer over the surfacer does not make sense-- and the data sheet says so.

Etching primer contains acid, some paint manufactures have a recommendation for applying it OVER plastic filler but only when the plastic filler is well CURED 12 hours.

It is never (that I know of) recommended UNDER plastic filler, the polyester resins and the acid don't get a long.

So just for argument sake, I do apply it over the plastic filler but NOT MUCH. I want it on the bare metal that surounds the plastic filler so I apply it there. Of course some is going to get on the plastic filler and if it is well cured, so what.

But as JWagner said "putting the etching primer over the surfacer does not make sense" and he is right. To apply it over the plastic filler will do nothing for you, but under "some" paint manufacturers guidelines, it is ok.

If you are using PPG and they say No then do as they say, but a little dusted over the edge (of fully cured filler) while you are applying it to your bare metal won't do a thing.

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

Wait a second here! You are reading your P sheet right. The Filler p-sheet says not to apply the FILLER over anything BUT bare metal or epoxy primer. There is nothing new about that, epoxy primer is a great base for plastic filler. And of course bare metal is also a great base. Urethane primers and etching primers are not.

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"