I need to find a rust patina that I can apply to a copper element in
a piece I am making. I am hoping I can make it look like the rust you
would find on steel, old cars, etc. I could purchase something ready
made if it isn't expensive but a formula would be great if the
ingredients were easy to get (in U.S.) and again, not too expensive.
Had you thought of using some piece of actually rusty iron? it would
be really authentic.
To join it to the rest of the object, you can silver braze it so
long as its bright and clean, and then stabilise the rust with
phosphoric acid and then a clear laquer.
Its not as tho its an expennsive piece of metal to run some trials
Getting an iron rust on copper is not a "normal" thing to do. f you
are after the "color" of iron rust on copper, that is pretty easily
doable. For into, materials, etc, call these folks. They are
helpful, know what they retaking about and can send you what is
decided upon. Good luck.
The folks at Micro-Mark make a material that looks like rust. It is
for model trains and scenery. Give them a try.
Check out the Swellegant line of products. Amazing stuff. Works
wonderfully on copper! I've been using it for a few years. (No, I'm
not connected to the company) It's inexpensive. And, it works!