DIY hot blueing
Posted: 10 Dec 2022 12:43
I did a little research on it and found that it can be done in a few different ways, and also using a few common ingredients.
The chems that I used were Spectracide stump remover which is reported to be near 100% potassium nitrate (salt peter). And common Lye drain cleaner (sodium hydroxide). I found a few different ratios, and that told me that I didn't have to be very specific about that part of the process. So I put some of one and some more of the other into a small steel vessel I had made to melt lye in for getting the varnish off of copper wire that I use for rewinding RC boat racing motors.
This little container was almost big enough to completely submerge a muzzle brake that I had made for one of my bolt action rifles. It takes a little while for the propane torch to heat the chems to the point that they go into a liquid, but once there, with the brake on a long piece of steel wire. I SLOWLY lowered the part into the caustic bath. After maybe 8-10 minutes I took it out, sprayed with water, then diped into water to cool it, and gave it a look. It was turning black pretty well. I buffed it down with 0000 steel wool, and degreased with brake cleaner. Dry with a het gun, and then put back into the solution for a while longer.
I would take it out occasionally to look at the progress and when I though it looked good enough, I cooled it down, cleaned with soapy water. Dried and then oiled it good and that's when it really turned dark. It looks about like the factory blue on my old Remington that it's screwed onto. So much of how the blueing looks, depends on how you finish the metal before you blue it.
This is a fairly dangerous way of doing this type of blueing because the molten chems have to get around 650-700 to go to a liquid. That's on top of the caustic nature of the chems. And I have read about a method of using the same chems but dissolving them in water and boiling your parts @ 275*F
I'll try that method next time so that I can immerse the whole part at once. But I think it turned out nice for a first try.
The chems that I used were Spectracide stump remover which is reported to be near 100% potassium nitrate (salt peter). And common Lye drain cleaner (sodium hydroxide). I found a few different ratios, and that told me that I didn't have to be very specific about that part of the process. So I put some of one and some more of the other into a small steel vessel I had made to melt lye in for getting the varnish off of copper wire that I use for rewinding RC boat racing motors.
This little container was almost big enough to completely submerge a muzzle brake that I had made for one of my bolt action rifles. It takes a little while for the propane torch to heat the chems to the point that they go into a liquid, but once there, with the brake on a long piece of steel wire. I SLOWLY lowered the part into the caustic bath. After maybe 8-10 minutes I took it out, sprayed with water, then diped into water to cool it, and gave it a look. It was turning black pretty well. I buffed it down with 0000 steel wool, and degreased with brake cleaner. Dry with a het gun, and then put back into the solution for a while longer.
I would take it out occasionally to look at the progress and when I though it looked good enough, I cooled it down, cleaned with soapy water. Dried and then oiled it good and that's when it really turned dark. It looks about like the factory blue on my old Remington that it's screwed onto. So much of how the blueing looks, depends on how you finish the metal before you blue it.
This is a fairly dangerous way of doing this type of blueing because the molten chems have to get around 650-700 to go to a liquid. That's on top of the caustic nature of the chems. And I have read about a method of using the same chems but dissolving them in water and boiling your parts @ 275*F
I'll try that method next time so that I can immerse the whole part at once. But I think it turned out nice for a first try.