removing paint

["Junior the Mean Widdle Kid" <rrudd28@xxxxxxxxx>]

I remove paint/primer from cars almost on a daily basis.  The main thing you
want to look at when you're removing paint is the end goal of what you wish
to accomplish.  Even when it comes to removing paint for prep/repair, there
are different methods, some of which you do not want to do in certain
situations.

The easiest by far is chemical "aircraft" remover.  I do not recommend this
as it's quite the nasty job.  The chemicals are volatile, the chemicals used
are harmful to just about everything not man-made, and these chemicals need
to be completely neutralized lest they come back and destroy your paint job.
If you absolutely have to do this, take it to a professional and let them do
the dirty work and let them deal with the EPA.

If you're stripping paint to repair rust, the best that I've found is a 24
grit grinding wheel.  I use a CP pneumatic 7" one, though, this can be
rather big for confined areas.  You can use smaller size wheels found at
paint and body stores, Lowe's, Home Depot, and Sears.  This is the fastest
and most effective way to remove everything in preparation for welding or
making a fiberglass patch panel.  Unfortunately, after you use this, you'll
need to sand it with a DA or file sander and work from 36 grit to 180 grit
as 24 grit scratches will show through paint and primer.  Another big
drawback is that these grinding wheels generate a lot of heat and can warp
panels if you let it build up.  If it's glowing red, and it's not a weld
you're grinding down, you're running it too hot for stripping paint.

If you have surface rust, and wish just to sand it down to bare metal the DA
works best.  A random orbit is okay, but I have  DA and not a random orbit
so I use the DA.  For this, you want to start off with 60-80 grit and work
your way up to 180 grit.  Then, block sand it with 220, then primer.  Then
sand with 400 then 600 to prepare for paint.   Most quality DA's are
adjustable so you can control the speed of material removal.  My IR
'handle-style' DA will strip to bare metal at full blast and 80 grit in
under 10 seconds.  My hand held Hutchins will do a similar job in about a
30.

If you're in a tight spot, the de-rusting wheels are around 24 grit, and do
a fine job if you're cleaning up a seam you wish to weld a panel upon.

Now, this is a little known fact, but there are 2 different kinds of
sandpaper.  There's "American" and "European" standard paper.  This is
extremely important!  American sandpaper, primarily made by American
companies (Norton, 3M) has a number only (80, 180, 220 et al).  European
paper, specifically Mirka (Finland) has a "P" designation before the number.
This "P" actually means that the paper is about 1 grade less than American
paper.  By grade I mean that if you had 80, P-80 would be roughly 60 grit.
I didn't know this till a PPG rep told me about it.  Sandpaper is sandpaper,
and the better brands are going to be comparable in quality.  Auto sandpaper
should be wet/dry if purchased in sheets.  Self-adhesive paper (purchased
for round DA's etc) isn't always wet/dry.