JTknives
Blade Heat Treating www.jarodtodd.com
- Joined
- Jun 11, 2006
- Messages
- 8,630
Most of you know we do customer heat treating in my shop and with the move I have been thinking about coughing up the bucks to run gas in the oven. My thoughts are as such so correct me if I'm miss guided or off in left field.
We are coming to the end of my big foil roll and it's rather pricy to replace it (24"x100ft 309SS $500-$800). I don't inherently dislike foil but it's not something I look forward to doing. And sometimes we double wrap big blades as thy try and poke holes in single layers. I know it's hard to quantify a price per blade for foil but if each pouch was 3"x12" not including the folds (double folds on all seams) you would be looking at 400 blades from a 100ft roll. That's over a buck in foil for each blade. And you can't reliably wrap carbon steel blades. I do get blades that stick to foil making it a pain in the ass to remove and clean. I would also say your blade heat up time is slightly slowed but that's just a guess.
My thought is if I went to injected nitrogen a lot of the drawbacks of foil would be over come. Things like air hardening only, sticking, wrapping, cuts on fingers and high up front cost. I called my local gas suplyer and he will sell me a 228cf bottle of nitrogen for $250 and fills/exchanges are $34. Talking to Salem who runs gas he uses 5CFH to be scale free in his paragon. But that's argon settings which translates to 6CFH of nitrogen as it's less dense. So the same volume flow of nitrogen would be close to 4CFH of nitrogen if your using a argon flow meter. I know you will get a tiny bit of scale going from the oven to the quench oil/plates.
But all that aside if we just ran 5CFH of nitrogen that's 228/5=45.6 hours of shielding. Avarage high temp heat treating is 1/2hr so we are talking about 90 blades per tank. That's not counting carbon steel blades that are 5-10min each. If you just did those you would be 3 times that number. So to compare prices it would take 400foil/90gas=4.44 tank refills to do the same number of blades as the foil. That's 4.5x$34=$153 vs $500-$800 in foil. That's $153/400 .38$ a blade vs the $1.25-$2.00 a blade. With those numbers I could run double or triple that gas flow and still be cheeper.
I'm thinking I will seal around all the Metal sides with high temp silicone so it's as sealed as I can make it. But I have never used gas befor so this is all just speculation. Thanks guys.
We are coming to the end of my big foil roll and it's rather pricy to replace it (24"x100ft 309SS $500-$800). I don't inherently dislike foil but it's not something I look forward to doing. And sometimes we double wrap big blades as thy try and poke holes in single layers. I know it's hard to quantify a price per blade for foil but if each pouch was 3"x12" not including the folds (double folds on all seams) you would be looking at 400 blades from a 100ft roll. That's over a buck in foil for each blade. And you can't reliably wrap carbon steel blades. I do get blades that stick to foil making it a pain in the ass to remove and clean. I would also say your blade heat up time is slightly slowed but that's just a guess.
My thought is if I went to injected nitrogen a lot of the drawbacks of foil would be over come. Things like air hardening only, sticking, wrapping, cuts on fingers and high up front cost. I called my local gas suplyer and he will sell me a 228cf bottle of nitrogen for $250 and fills/exchanges are $34. Talking to Salem who runs gas he uses 5CFH to be scale free in his paragon. But that's argon settings which translates to 6CFH of nitrogen as it's less dense. So the same volume flow of nitrogen would be close to 4CFH of nitrogen if your using a argon flow meter. I know you will get a tiny bit of scale going from the oven to the quench oil/plates.
But all that aside if we just ran 5CFH of nitrogen that's 228/5=45.6 hours of shielding. Avarage high temp heat treating is 1/2hr so we are talking about 90 blades per tank. That's not counting carbon steel blades that are 5-10min each. If you just did those you would be 3 times that number. So to compare prices it would take 400foil/90gas=4.44 tank refills to do the same number of blades as the foil. That's 4.5x$34=$153 vs $500-$800 in foil. That's $153/400 .38$ a blade vs the $1.25-$2.00 a blade. With those numbers I could run double or triple that gas flow and still be cheeper.
I'm thinking I will seal around all the Metal sides with high temp silicone so it's as sealed as I can make it. But I have never used gas befor so this is all just speculation. Thanks guys.