Subject: painting on bronze?

From: [email-masked] (Jacqueline Hamilton)
Date: Tue, 11 Oct 1994 01:12:01 GMT

I've had some pins cast in bronze, and I want to paint them.  I'm not 
very pleased with the results of acrylics on bronze, though; the dried 
paint tends to scratch and peel off too easily.  Is there another, more 
durable type of paint I could use?  It'd help if it was airbrushable 
paint.  I'm considering trying acrylic enamels, next.

Any info appreciated....

-j.

--
-Jackie Hamilton
[email-masked]
http://fohnix.metronet.com/HomePages/kira/newhome.html

---

From: [email-masked] (David Jenkins)
Date: 12 Oct 1994 14:09:00 GMT

>From  article <[email-masked]>, by [email-masked] (Jacqueline Hamilton):

There is a fundamental problem with copper-based alloys - normal paint
simply won't stick.  This is something I've had to deal with in my hobby
(steam locos) while trying to paint all the brass sheet, etc.

The answer is to start with an etching primer which is, as its name
suggests, a paint with an acidic base which etches the surface of the metal
slightly.  This, combined with rigorous surface cleaning, will do the trick.

The hard part is finding the primer...

I don't like the cellulose-based etching primer sold to model engineers, as
it clogs the paint jet and doesn't stick too well anyway.  I have also used
two-pack epoxy primer which was excellent, but is hard to buy due to its
considerable health hazard (we're talking full suits and closed-air
respirators here!).

My latest discovery is the aerosol paint used for plastic car body parts -
it etches in nicely and takes some shifting.  Don't take my word for this
though - try it out on some scrap & see what you think.  I haven't found
anything better to date.

-- 
David Jenkins

"This looks like a job for... somebody else!"
	- Plucky Duck