Brownells non-scale compound in the forge

[clint c]

Just for your guys information, Brownells non-scale compound, as used by Terry Primos in his heat treating tutorial, will work in the forge. It looks a little messy in use, but boy does it clean up nice after heat treat, and leaves no scale or pitting behind to clean up.

I recently heat treated several knives in my forge, which I kept at a fairly consistant 1600 degrees. I warmed each blade to around 500 (blue), applied the NSC with a spoon ensuring a good coat. I normalized each blade three times and finally quenched in warm Canola oil. They all turned out great. Anyway, when asked, Terry said that he'd heard the stuff won't work well unless your using an oven, but now we know it can.

 

[Chris Crawford]

Hey Clint, Thanks for the information. I have one of the 1lb cans of the non-scale sitting in the shop, but I've not used it yet. I do all of my heat treating in the forge also, so it's good to know that it works well. -chris

 

[Guy Thomas]

Has anyone tried using straight borax as an anti scale step while heat treating? I know Karl Schroen in his book on forging knives advocated dipping the blade in a super saturated solution of borax and boling water and then letting that dry prior to heat treating. I'm very intersted in controlling scale since I typically have the blade very close to it's finished state prior to heat treating.

On my earlier knives this wasn't as much of a problem but now I normalize several times prior to quenching which creates more of a chance for tough scale to form.

I suppose I should experiment on my next batch of knives.

 

[clint c]

I've tried a borax coating during normalizing cycles and quenching, and it does seem to have some positive points. It seals the blade from carbon loss during said heat cycles, but you do end up with pitting afterwards. I suppose this should be expected, as borax acts as the flux when you forge weld damascus, and part of it's job is to "clean" the steel (ie. acts like a mild acid.) This is why we end up replacing our forge floors after alot of damascus making, as the borax eats it, as well as steel! In short, the non-scale compound is a better alternative, as it's way easier to clean up afterward, it protects a near finished blade during the heat treat, and you don't get the scale and pitting. Thats my opinion after trying both anyway.