Blackening cast stainless steel

Jewelry Discussion
1

Hello Everyone,

I’m working on a stainless steel cast ring for a customer that I
need to blacken. I have looked into some chemicals such as
Ultra-Black 407 but unfortunately it won’t work on cast steel. I need
something with a surface finish that will last and hold up to wear
and tear.

Any advice is welcome.
Thanks,
Christopher

2

Christopher-

Find a gunsmith and have them apply an English Blackening patina.
It’s the most durable patina.

Good luck.
K.

3

I do not believe you will find anything that is both a good black
and durable. I have looked and tried a multitude of
coatings/patinas/processes for blackening stainless and none of them
were very good. There are some commercial scale processes that are
ok but not suitable for one off projects.

James Binnion
James Binnion Metal Arts

4 
I do not believe you will find anything that is both a good black
and durable.

I guess that’s why they call it stainless. LOL

5

Hi: The whole point of stainless is that it’s hard to oxidize, at
least at room temperature. Luckily it will oxidize easily when
heated to a red-orange heat. Just let it cool in air. The resulting
scale is quite tough, though it can rust in the right conditions.
Should not be a problem if the ring is worn continuously.

Best, Phillip Baldwin

6 
Hi: The whole point of stainless is that it's hard to oxidize, at
least at room temperature. Luckily it will oxidize easily when
heated to a red-orange heat. Just let it cool in air. The
resulting scale is quite tough, though it can rust in the right
conditions. Should not be a problem if the ring is worn
continuously.

Hi Philip, Steve and I tried several way to develop heat scale on
stainless and found the color to be uneven and the surface rough.
And as tenacious as that scale is unfortunately I don’t see it as
tough enough for rings.

Regards,

Jim

James Binnion
James Binnion Metal Arts

7

I am a gunsmith and am unaware of any patina or process that will
reliably darken stainless steel. I would be very interested in
finding one. I have never heard of “English Blackening Patina”. I
would love to converse with the gunsmith you found that does this
process. Gunsmiths unfortunately like jewelers are not very
forthcoming with that type of Sometimes it is a
guarding of the sacred knowledge but I have found it is often just a
simple no one ever asked me so I never told anyone. We are all busy
making a living and taking time to write down a process rf teach
someone is not a top priority. I am a believer that much of this
is going to be lost unless it is passed on to the next
generation of craftsman.

Billy Mayfield