Borax as Anti scale powder

alaska dave

Member
I came across a cheaper method of anti-scale powder and wanted to see if anybody had tried this or knows if it is a bad idea (and why). So far it has worked with 1095 and 01

I use 20 Mule Team Borax as an anti-scale powder but not straight out of the box. The problem with normal borax is it has water in the powder. So you need to remove the moisture. Poor the borax on a tray and place it in the oven at 350 for thirty minutes or so to evaporate the water. The borax will now be in clumps, place it in container and pulverize it back to powder form. I use a wooden hammer handle and grind it slowly back to powder. Make sure and store the powder in a sealed container so it doesn't absorb moisture again. To apply the powder I preheat the blade to 500 F then sprinkle it on using a small mason jar with 1/64" holes punched in the lid like a salt shaker.

Compared to no treatment the level of scale is greatly reduced. After quenching in oil most scale just pops off with a light scrubbing before tempering. As it was explained to me the problem with Borax out of the box is the moisture content, the water cools the steal and creates a barrier to the adhesion of the borax. Try it, put regular borax on a hot blade and it will sizzle and steam, then try the dried out borax, no sizzle or steam.
 
Awesome tip to try. Thank you. I've been using the anti scale grey powder and I swore I'd never HT a blade without it but hearing this tip , one never knows. Thanks again for the tip.
 
If you will try ATP-641, you will find it both economical and very good when used below 1600°. It is painted on and allowed to dry. I paint another coat on the edge area. A jar of it goes a long way, and it works.
 
Borax is corrosive,... pits, and eats away at the steel. It basically eats the oxides off. Don't think it really offers much oxygen shielding.

... I think using a reducing or carburizing atmosphere makes better sense than using any compound. I've heard some of them can contaminate you furnace lining,... borax for sure.
 
Last edited:
I've been using ATP products and it works very well. On O-1 I first degrease the blade up to and including the ricasso, I then dip the blade in the ATP and hang to dry. I then paint on a coat over the edge and let that dry. When you go to quench the material flakes off, leaving a clean surface.
 
No matter what anti scale compound you use there can be issues when the blade is quenched. Any coating applied to the blade can and will slow the speed at which the blade cools. A steel that requires a fast quenching speed has little time to make the pearlite nose as it is; by applying any anti scale compound a little thick and it might not make the nose at all. I've used PBC paint on anti scale as you would clay, on W2 and got a nice hamon. I use anti scale through all the heat cycling runs but when I go to harden the blade I use an argon atmosphere in my electric kiln.
 
Back
Top