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Brass and copper discoloration


#1

Hello Fellow Jewelers,

I’ve been working with brass and copper since the silver price has
gone up.

I’ve been having lots of difficulty preventing discoloration even
though the pieces are cleaned thoroughly after fabricating. Most are
quite small, so getting between bezel and mounting is a real
challenge.

I read somewhere on the net to use wax. aka paste auto polish to
finish the pieces. this just made things worse. I tried tumbling.
That did little to help.

Does anyone have any suggestions-tried Krylon triple thick. Any
little millimeter not covered will tarnish.

Aruuugh!
Thanks for any help from this crew.
tiddlewink


#2

Jeanne,

Copper is just a VERY reactive metal, and the acids on the surface
of our skin makes things even worse. The only thing I know of that
will work for a shoe is using very high quality clear coats. I do
not make much jewelry, but I do a lot of work in bronze and for the
last few years, sprayed copper on architectural pieces, antique cars
and some art items. (there is also a clear coat MADE for copper and
it’s alloys called Incralac (thinner based) and Syncrlac (water
based) used a lot on bronze sculptures that are outside. About a 15
years life and pretty easily removed with MEK solvent then re
applied, without damaging the patina it is protecting. It is also
waxed 1-2 times a year. Also for wax, the absolute best wax we have
found for our bronze sculpture is Leaberon. A bit difficult to find
but when I do, we buy it in large tins, about 1/2 gallon. Great wax
but expensive. Sculpt Neveau in Escondido, CA carries a lot of
material suitable for copper. I might suggest you give them a call
and see what they might suggest.

I have been very happy with a product from PAR, their catalyzed
clear coat urethane. It makes a pretty heavy coating, but seems to
work well on bright copper elements in the out doors. It is used a
lot on high end marine, polished items that can still be used, , i.
e. cleats used to tie the boats to a dock. It is VERY tough. It is
pretty dang expensive too, about $140.00 a quart in quart units
(less by the gallon and less still by the 5 gallons).

With ANY sealer you are applying, sharp edge, corners will always
have a far thinner coat of what ever coating you are using than the
flat areas, so if possible, always give edges a radius versed a
sharp, square corner. This thinning of any coarting on the sharp
edge is a problem in any materials and any fields, it is the nature
of things (and physics). Hope this helps a bit.

john dach


#3
I've been having lots of difficulty preventing discoloration... 

Jeanne, try going back through the Orchid Archives for several
discussions on this issue.

Judy Bjorkman


#4

Good Morning from Rainy Los Angeles (at last!!)

Metal clay jewelers are using something called PYM Protectant -
Aerosol as a sealant. Here is the quote from PMC Connection: Why we
like it: Unlike other sealants, PYM takes on the texture of the
surface being coated. Won’t transform your matte surfaces into
high-shine as other protectants can do.

I’ve tried a lot of sealants and they only seem to make the problem
worse by changing the surface character. You might want to give this
a try.

All my best,
Andi Alameda


#5

Copper & brass discolour - 'tis the nature of the beast - just like
silver will tarnish. Anything other than completely excluding air
won’t stop it doing so in the long run. Work with it, tailor your
designs to that fact, and explain it to your clients - and give/sell
them a polishing cloth!

Janet


#6

Not cheap to get set up to do but I love Legor 's nano ceramic
electro plating. Gets every where and no tarnish as well it helps to
protect the metal from getting scratched.

Panama Bay Jewelers


#7

I like what John said–have used the incralac for architectual stuff
but jewelry is another story–try- when polishing-first use high
speed buffer andwheels. 1st-brass-6" tight weave cotton (white) with
blue luxi compound-finish with loose buff with ultra fine white luxi
compound-if you want use turtle paste wax for a final protective
coating do so. Have no problems as my brass pieces stay brilliant
for at least 7-10 months. 2nd -copper-sameprocess as brass attached
pics that were taken several weeks ago–of several pieces that are 1
yr old. What might look as discolor is actually reflections.

http://www.ganoksin.com/ftp/jewelryspamsales4050.jpg
http://www.ganoksin.com/ftp/jewelryspamsales4070.jpg
http://www.ganoksin.com/ftp/morejewelry013.jpg

Hope this helped
Mark Moore


#8

Thanks to all you Ganoksin gurus,

I did search the archives and found lots of suggestions.

Thank you for all your helpful advice posted recently.

Tried and removed lots of different sealers on many different
scraps.

Read and tried suggestions in Jewelry books. I found that the sprays
create pebbles on the surface of shiny metal surfaces. Tricky
spraying.

OK for small stuff like earrings though.

Will keep working at it.
Thanks again,
Tiddlewink