I typically use a metal-prep solution, followed by DuPont Prime & Seal.
However, I have used DuPont Variprime before and if I recall, I believe that
Variprime is listed as a self-etching primer-sealer and does not require a
primer-sealer coat over it (although it certainly wouldn't hurt anything to do
so). At least I've been told by two different DuPont distributors that
Variprime is a good sealer and can be immediately topcoated. Call your local
DuPont dealer to get another opinion. What they probably will tell you is that
if you have any minor surface imperfections that you need to fill, you should
spray a coat of sanding primer over the Variprime, then sand the surface
smooth. A sanding primer is a high-solids primer that isn't particularly
strong and doesn't seal well. It is primarily used for filling small
imperfections and it should always be sanded. Try not to leave a thick build
of sanding primer on top of the primer-sealer, or it could create a weak layer
between topcoat and primer-sealer.
By the way, the DuPont website showcases several vehicles that were primed
with Variprime or other primer-sealers, then painted with ChromaBase or other
paints (most also had a clearcoat, which you probably won't be using). Example
at http://www.dupont.com/automotive/finishes/topgun/62vette.html Another
showcased vehicle used ChromaPrime (not a sealer), followed by Prime & Seal,
then painted.
A sanding primer does NOT typically stick well to bare metal, but it should
adhere quite well to the underlying primer-sealer, as long as it is sprayed on
within a short time after applying the primer-sealer, or as long as you scuff
the surface of the dried primer-sealer with fine sandpaper or scotchbrite. The
advice for Variprime also applies to DuPont Prime & Seal, which is a two-part
zinc phosphate primer-sealer without the phosphoric acid etchant built in.
Technically, I guess that Variprime (or other two-part primer-sealers) can be
sanded, but it's not recommended. They form a very hard, thin coating that
doesn't fill imperfections very well. If you do sand the primer-sealer layer,
you should spray a fresh coat of primer-sealer on afterwards to make sure that
all of the metal is propertly sealed.
One caution with Variprime: unless the formula has been changed recently, I
believe that it contains zinc chromate, which is nasty to breathe. Make sure
you use an approved respirator. Of course, you should use the proper
respirator no matter what type of paint you use, but be particularly careful
with chromates. You also want to be careful with two-part (hardened) paints,
since they often contain iso-cyanates. Again, the correct organic vapor
respirator should take care of it.
I've had good results with DuPont paints. Any of their two-part primers stick
better and longer than a visiting relative. Remember that if you use a metal
prep solution (also available from DuPont), you don't need a self-etching p
rimer, since the solution does essentially the same thing, microscopically
etching the surface to provide a good bond with the primer. You can use DuPont
Prime & Seal two-part zinc phosphate primer instead of the Variprime. It's a
little safer and has the advantage of being tintable. You can have it made up
in olive drab...or something close to it. This gives you added protection
against a different color of paint showing through if the paint gets scratched
or worn thin somewhere. The thing to remember when using the metal-prep
solution is to rinse it off before it dries. If it dries, just wipe it again
with some fresh prep solution, then rinse.
Paul mentioned water-based epoxy paints. These may be a very good approach,
but I'd do some further research on it. In an earlier posting, someone
(Gordon, maybe?) had mentioned some problems with these paints breaking down
in tree and bird droppings.
By the way, as I mentioned earlier, I heartily agree with Paul's advice to use
an HVLP system.
To tell the truth, I'm not familiar with the MVPA authenticity ratings on
paint, but I imagine that the color and luster are very important, as would be
the manner in which it is applied (what is painted vs. what isn't, etc.).
Perhaps thickness is also a factor?? At any rate, I personally wouldn't
hesitate to use a higher quality paint than the original, as long as I could
match the luster, color, etc. If I go to a lot of work to get rid of rust and
otherwise prepare the vehicle for painting, I'm going to try to protect the
metal as well as possible, even if it means using more modern paints. I can be
rather picky about restorations, but I don't feel any guilt at all about using
modern paints.
Alan
(Salt Lake City, Utah)
-----Original Message-----
From: paul vandervort [SMTP:pgv@imaxx.net]
Sent: Tuesday, August 26, 1997 2:43 AM
To: RKiser8375@aol.com
Cc: mil-veh@skylee.com
Subject: Re: [MV] Painting my M37
The best action that you can take is to apply a self etching primer (Du
Pont Variprime), then a primer/sealer (Du Pont Velvaseal), then your
Olive Drab (No I'm not promoting Du Pont but that is what I have used &
it it works very well).
===
To unsubscribe from the mil-veh mailing list, send the single word
UNSUBSCRIBE in the body of a message to <mil-veh-request@skylee.com>.