[Top] [All Lists]

Re: [oletrucks] Wet sanding

To: "A.B." <bigfred@unm.edu>
Subject: Re: [oletrucks] Wet sanding
From: Grant Galbraith <trks@javanet.com>
Date: Thu, 25 Jan 2001 08:45:54 -0500
I also don't like using rattle can guide coats, though I feel guides coats are
necessary for me. I just can't see imperfections, when the final coat is on it's
too late. People say you sand the guide coat off but I don't feel you get it out
of pits and other low spots. I  use  a 3'M product for guide coat, it is not 
but a dry powder you rub on, similar to charcoal that you can wash off before 
next coat or using "icing" filler.

50 Chevy 3100
52 GMC 150

"A.B." wrote:

> Sounds like good technique overall, but I dont' like to spray a guide coat
> on my *final (wetsanded)* primer.  Maybe I'm paranoid, but I dont' like to
> mix the chemicals in the spray can paint with the chemicals I'm going to
> lay down in color coat.  I was taught that a guide coat is for looking for
> highs and lows in the final stages.  After those are all found, the last
> layer(s) of primer are layed down and wet sanded with a pad (or block).
> When it feels like glass, I know I'm done.  I realize your sanding the
> black guide coat off, but it seems sketchy to me... I'm totally *not*
> saying your technique is bad, just trying to put out another point of view
> for those who are not sure how the final stages of paint prep work.
> -alfie
> On Wed, 24 Jan 2001, BelAir Bob wrote:
> > Tom,
> >
> > There are two stages of the paint process when you can wet sand.  The first
> > is the final sanding of the primer coat before painting. The second is after
> > the paint has dried before polishing.
> >
> > I'm sure others have different techniques for wet sanding but this one was
> > taught to me by a buddy who produces consistent show winning paint jobs.
> >
> > The pupose of wet sanding the primer is to produce a MUCH smoother paint
> > finish.  The technique I use involves a five gallon bucket of warm water, a
> > few drops of dish soap, a large sponge, 600 grit 3M Wet or Dry sand paper
> > and a can of cheap flat black spray paint.  I do not use a sanding block for
> > wet sanding.  The procedure starts by applying a "guide coat" of flat black
> > spray paint.  This coat should be nothing more than hazy black stripes a few
> > inches, 4" to 5", over the entire piece to be sanded.  You don't want to
> > make solid black stripes, they should look a little heavier than just over
> > spray would.  The purpose of the stripes is to indicate where you have
> > sanded and where you may have missed a spot.  I start by soaking the
> > sandpaper for about 30 minutes to soften up the paper.  This makes the paper
> > backing more plyable.  The actual process of sanding starts with me cutting
> > each sheet of paper into thirds and folding the piece I'm going to use into
> > thirds.  I "load" the sponge with water, wet down the area where I'm going
> > to start and then begin sanding in a circular motion.  You need to be ver
> > cafeful not to sand with your fingertips.  This can cause shallow groves in
> > the primer coat.  Instead, keep the paper back under you fingers, say from
> > the first knucke down.  This gives good even sanding pressure.  Be sure to
> > take off and rings you might normally wear and even trim you finger nails.
> > The finger nail thing sounds funny but I have seen "sanding scratches" from
> > a buddy of mine that has particularly thick finger nails and bad sanding
> > technique. There are times when you will have to use you fingertips to sand
> > but just go easy when you do.  As I sand with one hand, I keep a constant
> > trickle of water running from the sponge.  You can tell when you aren't
> > using enough water when the paper sticks to the surface.  Be sure to dip the
> > paper in your water bucket fairly often to rinse of the "sludge" that builds
> > up on it.  I continue on in this fashion until all of the guide coat is
> > gone.  I finish the wet sanding procedure with a good wash job, water with a
> > tiny amount of dish soap,  of the entire piece and a complete drying with
> > disposable towels.  In my experience,  if I have done a propper job of
> > sanding, the primer will actually have a low shine to it.
> >
> >
> > Wet snading the finished paint before polishing is done with the same basic
> > technique with a few exceptions.  First and foremost, do not spray a guide
> > coat.  Second, at this point I actually sand the entire piece twice, once
> > with 1500 grit and once with 2000.  After the water has been dried from the
> > sanded piece any area you missed will be glossy.  Once all the missed areas
> > are sanded you can polish the paint.  I don't do the polishing so I can't
> > comment on the procedure.
> >
> > I hope this rather long winded explination helps.
> >
> > Robert Rogers
> > 57 Belair Sport Coupe restored to original
> > 55 -2 3105
> > 55 -2 6400
> > 55 -2 3100 Wife's project
> > 57 3100
> > 82/86 GMC Sierra SLE Crew Cab 1/2 ton short bed (For Sale)
> > and a few others
> > 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

<Prev in Thread] Current Thread [Next in Thread>