<VV> Re: Primer Sealer

[vairologist at juno.com]

> From: Joel Rushworth <gwydionjhr@shaw.ca>
> Subject: Primer/Sealer/Gloss was RE: <VV> Old rims question.

A couple of guys up here have taken to using a sealer on the car 
> before the mud and primer go on.  The idea being that bondo absorbs
moisture 
> and they want to put a barrier between it and the metal.

----------------------------------
Smitty says:  I'm a jack leg painter but I do have a good many years of
experience.  I consider that "bondo (body filler) absorbs water" thing to
be a load of crap.  I have heard it for years, mostly in relation to wet
sanding and how the surface stays wet for a bit when you dry it.  That is
a result of the water being retained in the sanding scratches.  Given
reasonable time to dry, it will.  Also the finding of rust under bondo in
an old repair is a result of lousy prep work on the metal.  If the metal
perforations are closed up and the metal is properly treated before the
primer, you will never have any rust till the metal rusts through from
the back side.  All bets are off then.  The new self etching primers are
sometimes recommended to be used before body filler is applied.  That's
fine, but is for the same purpose as treating the metal before old
fashoned primers are applied.
        Hardly conclusive of anything, but I once formed a little flower
pot of body filler 1/8th to 1/4 inch thick and about an inch in diameter
and about three inches long.  Hung it in a coffee can of water almost up
to the rim.  Planted a seed in it and watered it till it sprouted, then
quit watering.  I had a bet with a neighbor.  Damn thing died like I knew
it would.  Polyester rosen and epoxy rosen are impervious to the
penatration of water.