Preventing uneven heating

On a couple of them, yes, there might be uneven heating, as the burner goes into the square or rectangular chamber at right angles, so there's no swirling effect, and a hot spot is created...
Most of them look to be okay.
 
If in doubt about hot spots, move the blade to a different spot in the forge every 20 to 30 seconds.

Jim A.
 
Mine has definite hot spots. Its a rectangular box with two burners on top and open end ports (NC Tool Whisper mamma). I just keep that blade moving. I haven't had trouble with uneven heating, but it is a bit more work to get an even heat. I'm in the process of gathering the materials for a round horizontal pipe forge using IG's plans.
Ed
 
Interesting, so putting the burner at a 45 degree angle or so and moving the blade every half minute should prevent uneven heating?

I've never used a forge like this so approximately how long would it take to heat a 9 inch total length blade in low alloy steel to non magnetic?

Edit: sorry, I just saw the other threads about this, which is weird since I didn't see them before and did a search?! Very strange, anyway sorry for that.
 
Most new makers have uneven heating in the NC type forges because they only run them wide open.(sort of like when we first started using the accelerator on the car).Turn down the gas pressure after the oven comes up to temperature.The whole forge should be at the desired temp,not at welding heat(unless you are welding).This is why so many newbies ask "How can you keep the blade in the forge for 5 min. and not overheat it?" A thermocouple and gague will help in knowing the chamber temp.If you are mechanical you can make an electrical controlled gas valve the works with a temperature controller and keeps the chamber at a preset temp.
The other trick is to keep the balde moving.
Stacy
 
Thanks for the tips, I'll try that out. I was actually looking for thermocouples yesterday but couldn't find any E-types for sale.
 
Stacy -

I read your post a little too late. I "overcooked" an O1 blade last night (my second knife attempt). After tempering, I snapped it with fairly light pressure when trying to straighten a slight bend. VERY large grain, so I think I really overdid it. Next time, I'll turn down the pressure! And get a guage.
 
The same exact thing happened to me a few months ago when I made my first "blade" although that would be generous. 1095 file, I heated it to orange cause I didn't know better and soaked it for 10 minutes (:foot: )... When that thing came out of the quench i pryed a bit with it and it snapped instantly. Tempering would not have mattered, the grain size was clearly visible WITH THE NAKED EYE!! :barf:

I've learned a lot since then largely thanks to you folks!

:thumbup: for Blade Forums
 
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