Well done ssapatch. One day I'll give the hot caustic bluing a go, but I was always a little reluctant. I choose to do express rust bluing. You only need one tank and decent set of gloves (more to prevent fingerprint oil on the parts and thermal protection).
First hot bluing attempt (update: more projects)
- Thread starter ssapach
- Start date
I was trying to find someone locally to just build me some tanks, and it was going to be surprisingly expensive per tank. So I just got annoyed and ordered from Brownells. And then the shipping hit me, so I ended up paying the same as I would have to get them made right here.
Also, I should have gotten at least 1 stainless tank for my final clean water boiling tank. The steel tank rusts, the rust dirties up the water and it's just more work to keep clean.
Sending you a PM.
This is the tank I use. Very well made. https://www.canadaammo.com/product/detail/stainless-steel-parkerizing-bluing-tank-with-drain/
One possible source of potassium nitrate is a stump removal chemical like Spectracide. You can get it at Amazon.ca, or possibly Home Depot. Not so cheap though... $25 for a pound.
Spectracide Stump Remover
The on line MSDS sheets show it is 100% Potassium Nitrate.
Spectracide Stump Remover
The on line MSDS sheets show it is 100% Potassium Nitrate.
I honestly thought I could use Tannerite as a source for nitrates. But it's oxidizer is made up of ammonium nitrate and ammonium perchlorate (according to Wikipedia), and I'm not sure how the perchlorate would react....or if it would have negative effects on the bluing.
It would be slightly cheaper (not much though) than the potassium nitrate, and more readily available.
It would be slightly cheaper (not much though) than the potassium nitrate, and more readily available.
Maybe I missed it, but what does the addition of the third chemical do?
I got curious, so I did a little test. Made a bunch of steel coupons to blue for different lengths of time. Time was split up into 5 minute intervals, starting at 5 minutes and ending at 60 minutes. I made 4 sets of 12 pieces, each polished differently. First was just wire brushed to get the mill scale off the steel. Second was polished with 120 grit. Third was polished to 320 grit. Fourth set was polished to 800 grit. All the polishing was done with just a random orbit air sander, and of course I didn't cut deep enough to remove all the tiny defects from the steel mill. But it gave me a good idea of the differences in polishing and time in the bluing solution.
I also realized how difficult it can be to get good pictures of freshly polished/blued metal. So much glare....
Here's the full set of 800 grit:
And some more examples for your viewing pleasure.
Pictures don't exactly show the whole story, it's something that's best seen with the naked eye.
I also realized how difficult it can be to get good pictures of freshly polished/blued metal. So much glare....
Here's the full set of 800 grit:
And some more examples for your viewing pleasure.
Pictures don't exactly show the whole story, it's something that's best seen with the naked eye.
That's pretty much how I did the first gun, and it turned out quite nice.
I'm pretty sure the different types of steels account for differences in colour too. The rifle looks a fair bit darker, or more black, than any of these coupons.
Project #2, Ross 1905-R factory sporter. Check out this deep, shiny, purple-ish colour on the barrel! Caught me off guard when it turned out like that, but it's quite nice looking. Only problem is that it doesn't match the rest of the parts.
