Brass will absorb skin oils and such, which means that preparation is
-- absolutely clean - use solvents, detergents, and clean water. Handle
with museum-style cotton gloves, which you should change for fresh ones
at least once during this process.
-- use a solvent based undercoat designed for brass - acrylics will not
bond well with brass, if they bond at all. Bake the undercoat.
-- some people advise sand-blasting before painting, to create a "tooth"
for the paint to adhere to.
-- last time I painted brass, I used a solvent based paint, baked on at
about 120C. But even so, some of the paint flaked off later - I wasn't
careful enough in handling the shell after cleaning, and/or the ordinary
dish-washing detergent I used didn't get the grease and oil off
properly, and/or I didn't use an undercoat. So learn from my mistakes. ;-)
As Wolf said, surface prep is everything in getting paint to stick to
metal. First off, is the caboose bare brass or does it have a clear
lacquer coat to prevent tarnishing? Net rumor has it that any such
lacquer coat should be stripped off. I'd do some checking on that,
look for a Kalmback how-to-do-it book, or google for "brass model
paint". Assuming you do strip a lacquer coat, do a thorough job and get
it all. Then run the model thru the dishwasher. The hot water and
detergent will do a good degreasing job. Remove any non metallic parts
which won't stand water before you do it.
Then try to pickle the metal with a mild acid. Vinegar is strong
enough. It should make the shiny brass go sort of matte finish. Then
give it another trip thru the dishwasher. At this point don't touch the
metal with your fingers, the finger prints will make the paint fail to
Then do a prime coat. Use real automobile primer from the auto parts
store. This stuff is specially made to stick to auto body metal, which
is a little greasy, a little rusty and hasn't had the good surface prep
that you have just done. It has the best stick-to-metal qualities that
money can buy. Choose your color. Red primer makes a red finish coat
cover well, light gray primer makes a yellow finish coat cover better. I
assume you are going to paint the entire caboose one color (the base
color) and then mask off and spray on the second color over the first.
Pick a primer color to go well with your base finish color. Spray the
primer just right, not so wet it runs and drips, but not totally dry
either. You want a hint of wetness in the prime coat right after
spraying. Just a hint, not a drippy runny wet. When spraying, push the
button BEFORE the spray is pointed at the model, wave the paint spray
down the length of the car in an even sweep right off the other end.
Don't release the button until the spray has moved clean off the other
end of the car.
Let the primer dry good and hard. At least over night, a couple of
days is better. It dries better on a warm dry sunny day.
Once you have a good prime coat dry, it will paint like just like
plastic, so you can do the finish coats just the way you always do them.
I'm a bit puzzled. You posed the same question three months ago and
received, IMHO, some very good replies. Were any problems encountered
when following those suggestions? If so, could you share them with us?
Learning of any possible mishap might save some of us from falling
into the same trap. Thank you.
This topic could probably start a religious war. But in spite of all the
techniques tried over the years the best, and one favored by almost all
the Pro Painters (a dying breed so it seems) is to clean the Brass
thoroughly in Lacquer Thinner or Acetone followed by a warm soapy
wash/scrub and rinse. Noe of this is new or exciting mind you. The real
magic is in paint selection and curing. I would strongly urge you to
locate some of the old Scalecoat and apply thinned, light coats letting
them set up a bit before putting on a heavier finish coat and then while
still wet bake the painted model for a few hours. Make certain that the
oven doesn't cycle too high obviously but the paint job because
extremely hard and durable. And a nice gloss finish that takes decals well.
I just can't imagine painting Brass with non Lacquer Base paints. Did it
once and experienced a lot of peeling from masking tape (low tack).
Stripped and did the Scalecoat thing and voila... problem solved.
That completely slipped my mind. I received the model from the US just before
University started, and with the workload I haven't actually had a chance to
it yet. I've only just finished exams now, hence the accidental reposting.
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