I would even go further and eliminate chemicals of ANY kind. I have heard
from some of my other resources (like autorestorers.com) that chemicals get
into the weld seams and you simply cant get it out.. ever! So, after awhile,
the chemicals go to work on the paint from the inside and there is a good
chance of ruined or at least lessening the life of the paint job. Armed with
this info, I only dry strip. Bead blast all the small parts, dry strip (and
when the company doesnt do a good enuf job) RE-dry strip using a siphon
sandblaster and number 4 fine sand. There isnt any place I cant get to and
once cleaned I feel absolutely confident the job is ready for priming. Side
benefit is no caustic fumes and no mess that a shop vac cant handle. I am
sure this is all a matter of preference but as a novice at this, I try to
research these issues as thoroughly as possible.
Deve
50 3100
49 3600
www.speedprint.com/Deves50/index.html
----- Original Message -----
From: <ADvent@thuntek.net>
To: "BORDER,RYAN (HP-FtCollins,ex1)" <ryan_border@hp.com>
Cc: <oletrucks@autox.team.net>
Sent: Wednesday, March 29, 2000 10:35 PM
Subject: Re: [oletrucks] undercoating removal-fenders
> I am not a fan of the Por 15 type products. No, bondo requires a very
clean
> surface to stick to. I think if you need a product like Por 15, what you
really
> need is a more thorough cleaning. I prefer a chemical dip to clean things
up.
> Pitting is the worst thing that can happen with a chemical dip, but
certainly
> nothing the primer cannot handle. What will that Por 15 be like in 15 or
20
> years? Will it peel or fall off like cheap Japanese bondo or will it stick
like
> good bondo on a properly preped surface?
> new mexico jim
>
> "BORDER,RYAN (HP-FtCollins,ex1)" wrote:
>
> > I just went through this on my rear fender project (still underway). I
used
> > a good scraper knife with straight razor blades. I bought a pack of 100
> > razor blades for about $5 at harbor freight and went to town. Sometimes
I
> > used a heat gun to soften things up a bit though only when necessary, as
> > scraping it off cold doesn't leave a residue, using a heat gun tends to.
I
> > didn't have too much undercoating; and probably broke 10-15 razor blades
in
> > the process.
> >
> > Next I scrubbed the whole thing out with a stiff wire brush and a hose-
> > getting everything as clean as possible. Next step is to Por-15 the
> > underside of everything. Which actually brings me to a question: I
cover
> > the back-side of all my welded areas with fiber-glass re-enforced bondo.
I
> > use a disk sander to rough it out, but go ahead and leave it built up
just a
> > little to help strengthen the area. The area around the weld is
typically
> > surface rusted a bit; which the POR15 really likes to stick to. The
POR15
> > also seems to stick really well to the bondo. But, I'm a bit perplexed
> > about what to do in the area right around the weld:
> >
> > 1) Bondo over surface rust, POR15 over bondo... will the bondo stick to
the
> > slightly rusted surface OK? Will it continue to rust with a layer of
bondo
> > between the POR15 and the metal?
> >
> > 2) Sandblast area, bondo and then POR15. Seems this might hurt the
adhesion
> > of the POR15 to the metal in the area surrounding the bondo patch. And,
I
> > hate to sandblast of a layer of metal in an already weakened (welded,
> > ground-down) area.
> >
> > 3) POR15 and then bondo (then maybe POR15 again). Will bondo stick to
> > POR15 OK? Will the POR15 stick well to freshly welded and ground metal
(and
> > in many cases brand new metal patch panels). My experience has been
that
> > POR15 really doesn't like to stick to new metal very well.
> >
> > Up until now, I've been going with #1...
> >
> > Ryan.
> > oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|