Making shim washers

[marvin hedberg]

another product for darkening steel, cad plated bolts and brass/bronze is Brass Black. works for me.
https://www.amazon.com/Birchwood-Ca...+metal+finish&qid=1565879751&s=gateway&sr=8-3

https://www.ebay.com/itm/Birchwood-...820526&hash=item2ad238ca38:g:jvoAAOSwlf5dTkZM

 

[MachineTom]

AN addition to what has already been posted. To get a right OD, turn a piece of AL to the needed size, put a counter sunk hole for a center. Now part off, then sand, f Ile, turn to size of the AL you turned
.
Used this I glass with a file, came out great
Tom

 

[Harry.]

Is there another combination that you can use to get a darker matte finish that is closer to black oxide?
Or do you need sodium hydroxide and nitrates and hot tanks?

 

[Cogsy]

I have collected all the (easy and cheap) components to try the method from this video that seems very good. One day I'll give it a try:

 

[trlvn]

I have collected all the (easy and cheap) components to try the method from this video that seems very good. One day I'll give it a try:

Hey! Me too!! Looks like a simple process and the results in the video are pretty darn good.

Craig

 

[Harry.]

Great cold blacking video, it looks so simple. I wonder how the coating compares to the finish from hot blacking.

 

[Gopher Baroque]

Getting back to the original question, since thickness is the key parameter, I would probably
a) mark the ID and OD on shim stock
b) rough trim OD with snips (rough edge with margin to marked line)
c) hold in padded vice
d) finish with small die grinder (Dremel) with stone to marked lines. Grinding will take gentle cuts on thin stock to avoid distortion.
Although not perfect edge control, can be presentable with care and doesn't affect performance.