Heat treating with a gas forge

[samuraistuart]

"...I have to stick with my principles..." That is but ONE reason we respect you so much, Kevin.

About P50... my experience has been very good using it with steels like 52100 (never have used 5160) and even Cru Forge V and 1.2442. I did have one problem just the other day using P50 on a deeper hardening steel, however, and I attribute the failure to the fact that the P50 was just too fast for the steel and stressed it too much. 1.2519 (a deep hardening O7 series steel) Santoku, .100" spine and a 0.030" edge...P50 quench caused a bacon warp along some of the edge. The ONLY time I have ever had a bacon edge was when I messed up to begin with and had the edge too thin, ala 0.010". I remembered the past failures of bacon warp going into the HT on this 1.2519 Santoku, and wanted to avoid any possible bacon edge so the edge was left much thicker than I used to. Even at 0.030", I think the P50 was too fast. I can't think of any reason why that happened...other than the oil being too fast for the steel. Should have used the canola (don't have AAA).

interesting...I could have SWORN that I read from P50 tech data to not use it below 70F. PDF says it is as effective at 50F as it is at 120F. Could have sworn I read that 70F-120F at one time...hmmmm.

 

[Kevin R. Cashen]

Stuart, I too have sucessfully done many things that were not recommended. I put a cross vice on my drill press and used it for a mill for many years, until I found out the difference between mill and drill press bearings, but it worked until it didn’t. Last month when I got my Propane supply cut, I had to get a heat treatment done, so I rerouted full pressure from 100Lb bottles into the shop and let the regs at the salt bath take the load. Yes there were leaks while I was getting the job done, but I pulled it off and came away with a very successful heat treatment, and my life. Obviously, I am going to wholeheartedly endorse the methods and standards recommended for Lp gas installations regardless of my success.

Obviously the world does not come to an end if we bend manufacturer instructions, but should problems arise folks should know about those recommendations when troubleshooting. Every day, between phone calls and e-mail, I answer a lot of heat treatment questions, I would dare say it is the most complicated and confusing part of knifemaking, I just try to make it easier for folks whenever I can.