Re: Painting brass


Tim O'Connor
 


I've painted over a hundred brass models and have never used vinegar, and only once used
a grit blaster because there was oxidation on the model.

"Unpainted" brass is painted with clear lacquer because otherwise it oxidizes. To remove
this I bought a HUGE plastic storage jar and filled it with acrylic lacquer thinner. The
jar lasted about 15 years before the thinner began to attack the plastic... So anyway, I
would just drop the whole car (it was tall enough for a 90 foot autorack) into the jar
and let the thinner dissolve the clear coat. Then come detergent and warm water cleanup
and sometimes a bit of brushing to remove the coating from grabirons and such.

And Pierre is right, don't handle the dry clean brass with oily fingers! Been there, done
that. :-D



On 4/12/2020 10:33 AM, Bruce Smith wrote:
Mal,

Why do you etch in vinegar and then grit blast? To me that means that one of the two of those approaches is not working 😉. I would simply grit blast to give "tooth" and remove any tarnish or oxidation.

Regards,
Bruce Smith
Auburn, AL


From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> on behalf of Malcolm H. Houck via groups.io <Indian640@...>
Sent: Saturday, April 11, 2020 9:29 PM
To: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io>
Subject: [RealSTMFC] Painting brass
 
Painting Brass: --

Soak in solvent to make sure all flux and oils are removed;

Soak in white vinegar (nothing more that weak acetic acid);

Rinse and dry;

I blast in a cabinet with #400 Alox;

Most primer is nothing more than another (unnecessary) coat of paint, and
of questionable value when attempting a (chemical) bond to non-ferrous material
and so-called etching primers are formulated for ferric materials employing
phosphoric acid as the etchant (creating iron phosphate for paint to stick to);

But I do coat with a clear industrial preparation.......branded as "Steelcote"
(and consisting largely of purified shellac - once covered with the color coat
it's as durable as anything else);

Paint and then bake......I have stuff painted over thirty-five years ago
with Steelcote - Scalecoat.......trudged all over and about for display, packed, unpacked,
repacked, unpacked.......etc., etc., etc.,

Rarely any touch up..........

Mal Houck


--
Tim O'Connor
Sterling, Massachusetts

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