It has come to my attention that the company that made this product has gone out of business. Is anyone aware of a similar product that is still available?
http://www.migjimenez.com/en/12-burnishing-fluids
try this steve
Hey Steve, thanks for this option, and thanks for responding so quick!
I’m in the right hemisphere mate , only 8:20 in the morning here LOL
That is too funny, Steve. You are a hoot.
Hey…have you tried this stuff? Does it work pretty well? I remember reading that people recommended sealing the Blacken-It because the black coating would flake off. Is this your experience with the Mig product?
Go to your local sporting goods store in the gun cleaning dept. Look for Birchwood Casey products in a 3 oz bottle. They have products to blacken brass, and aluminum, and a bluing agent for a “gun blue” for steel. They all work really well.
This shows pintle parts for a rudder made with scrap PE brass. I didn’t like the parts painted.
EJ
I’ve only just ordered it for myself mate , at the moment I have master blackening agent , which can flake off .
Ok understood, Steve. Thanks.
Thanks for the input EJ, I will look into this as well. Your example looks pretty good.
When I did the brass parts for the pintles and guedgeons (sp), I was surprised it also blackened the solder as well. 
I did a google search on metal blackening solutions awhile ago- was amazed at what I found!
EJ, that is interesting about the solder.
A question for you EJ: Have you seen any issues with flaking? Do you seal it after treatment?
I have seen no flaking, such as you might see with paint. If scratched, of course, it will show. I have bent parts after blackening and seen no marring. I do not clearcoat after application unless I want a flat finish, then I use MM Dullcoat on the blackened part just like the rest of the model. The blackened brass and the blueing on steel are exactly like you see the finish on a blued firearm. Can be handled, cleaned etc, but would show a scuff or scratch if damaged. That said, if a scratch shows up, a bit of blackening agent put on the part with a fine brush, quickly re blackens the part evenly.
I discovered the solder part by accident. The guedgeons were made with flat brass stock, the fret part of some PE, bent to a kind of U shape to fit the rudder with the reciever made of brass tubing and soldered to the narrow edge of the part. The Pintles were made the same way with a pin of brass rod soldered into the tube. The gudgeons slid down on the pintle and turn nicely so the rudder actually functions. After the parts were made and test fitted, I put them in a cap from a milk bottle and added just enough solution to cover the brass, allowed it to soak a few minits, removed them with tweezers and rinsed them with water to remove excess solution and allowed them to dry. To my amazement, the solder blackened to the same color as the brass. I was using the solder called “TIX”, purchased from Micromark. The result you see in the previous post.
EJ, that sounds excellent. I will see if I can find some, locally. Thanks for the follow-up.
Sir, I just used super blue by Birchwood on my king tiger tracks and worked perfect. In fact way faster. Get this produce at a gun store. 3 oz bottle $13. Or buy it on line.
Hi Bakster!
I still have some bottles of the Original " Blacken-It" from when I did my last commission. This and the product sold by Mig-Jimenez work well. I have heard “Blacken-It” (THE MFGR.) Has gone out of Business. So use the “Mig” product! I like it!
Another place to look for metal coloring solutions is the guns section of sporting goods stores. My Walmart has aluminum black and gun blue.
I’ve taken to simply priming,painting,and weathering metal tracks the same as if they were plastic.