DEC beige/creame/white paint
rollerton at gmail.com
Wed Jan 10 21:05:04 CST 2007
On 1/10/07, Jules Richardson <julesrichardsonuk at yahoo.co.uk> wrote:
> Jay West wrote:
> > The scuffs on the top panel are pretty bad
> > so just a "paint stick" type of approach won't help. I'm going to be
> > looking at wax & grease remover, sanding, self-etching primer,
> > chipguard, and paint. What fun.
> If it's a flat panel (or a panel with no curves < about 120 degrees) then
> suitable wire brush attachment on an angle grinder can work wonders (just
> careful as too choice of brush as too hard and you'll scuff the metal too
> for a 'simple' respray).
> Personally I'm not a fan of solvents for this kind of thing as it's
> to be sure that all the residue's been removed afterwards (and hence that
> something left behind won't magically attack the new paint from below).
> Washing and drying can cause its own problems (surface rust, water
> deposits etc.)
> > So I took the panel into a metal paint shop in town well known for their
> > expertise to see about getting the paint matched. They said that since
> > the top is textured, the peaks & valleys will look brighter/darker and
> > thus you can't put a piece like that on one of those optical scanners
> > and get a good color match.
> I've always been told too that it's just not worth it on old panels as
> sun-fading will result in a match that isn't "original" and won't match
> other panel anyway. Matching by eye's a better bet (although personally I
> it difficult, but doubtless it's a lot easier for the professionals who do
> this kind of thing every day!)
> > Since I know absolutely NOTHING about paint/painting, I wanted to toss
> > this out on the list to see if what this place is suggesting sounds
> > right, and if the prices seem reasonable.
> Seems cheap to me, based on some of the quotes I've had before on this
> side of
> the pond. I've been told before not to mess around with aerosols though
> and to
> use a proper spray gun as the end result will be a lot nicer. I've zero
> experience of using a proper gun though, and have no idea how easy it is
> how much it would be to rent / buy one along with suitable compressor...
> Note that all of this advice has been from automotive paint specialists;
> don't seem to have such a thing as "public general-purpose paint
> around here. I'm willing to bet that it's just as sound for computer
> panels as
> it is for cars, though.
Jay, I paint old airplanes, cars and internal combustion junk now and
then. Those prices seem reasonable for good quality paint. Have you been
able to identify if the paint is (acrylic) lacquer or enamel? If its
lacquer then it will be a more forgiving process to refinish and dry faster
versus dry and cure for enamel.
Suggest you look at using autobody supplies from an automotive paint store
and avoid the Home places.
If the metal is Alum. then you need to do a few things differently.
Assuing its steel, first clean everywhere you plan to repaint. Start with
soap and water, rinse with hot water, then use a grease remover/prep solvent
(autobody store) cleaner, or if you can't get that use Naptha, wipe an area
to wet it and float the oils and then wipe it dry with another clean cloth.
You do this in about 12" x 12" areas at a time. What you are trying to do
is get the oils, waxes, and any silicone off the surface so it does not
contaminate the sanding process. There is stuff that soap and water will
remove, and stuff that a solvent will remove but neither will remove both,
thus the wash it and then use a degreaser is the right process.
Use some 80 grit wet/dry sand paper and a foam sanding block to open of the
scratches, and then move to 120 and then 320 grit paper to feather the area
between bare metal and good paint. Then scuff sand the entire item; you can
use sand paper or scotch bright pads. Using the foam sanding block
(autobody store) will help prevent sanding grooves into the old paint from
pressure from your fingers. Clean it all up using solvent. If there are
areas that are rusty, for instance the bottom of a deep scratch, you need to
get that out and down to bright metal... A wire brush, dremel tool, etc can
be used here. You dont want to wire brush the whole item, it will leave
scratches that will telegraph thru any new primer or paint you apply and
show on the surface of the new paint.
Spot prime the area. A self etching primer in a spray can is a good pick
for this. I use Mar-Hyde. You may need to build up layers of primer and
do a bit of spot sanding to get a totally flat and even surface. If the
scratch is deep or a dent then you might want to use a bit of polyester body
filler (aka bondo), or a glazing putty (autobody store) and then another
layer of primer. Wet sand the final coat of primer with 320 or 400 paper.
BTW, get a primer thats a similar color to the final finish, for instance
dont use dark grey or Red oxide for off white top coats, Mar-hyde has a buff
Ok, now clean everything up again; wash and solvent, wipe with clean cloth.
Then use a tack cloth (paint store, get a hand full)) to pick up any lint or
last minute dust.
Now you can paint. You have a lot of choces here, Acrylic Lacquer is the
easiest and most forgiving, Acrylic Enamel (often called 1-part paint). The
2-part systems start getting really toxic and I would not recommend you mess
with these unless you want to make a investment in some serious safety
Unless you have a perfect match in paint color and texture, you will want to
refinish a panel area; the gaps between panels break what the eye sees so
the imperfections in texture and color are not easily seen. Thats why
autobody shops want to repaint a whole fender or hood.
Also, 1-part enamel needs about 15 to 30 days at "room" temprature to reach
full hardness, even though its dry to the touch in say 24hrs. If you get
a run or a bug in the paint, you will have to wait for it to cure before you
can sand it out and try again.
There is a lot more detail and probably some stuff I left out or forgot that
would be in any good hot rod painting book so that might be a good place to
read up on this before you begin.
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