Propane torch for a forge?

M

Masterjuggler

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Dec 22, 2013
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I can't seem to find the answer to this question by researching, so here it is:

I'm going to be making my first knife soon (don't worry, I'll make a thread showing my plan and will document my build on it lol), and instead of sending it out for heat treatment, I want to do it myself. I have a propane torch (this one) and 2 green propane canisters that I opened up and riveted together for a 10 inch length.

If I put insulwool and refractory in it, would this torch get it hot enough to heat treat 1084 with? The back on the forge would still be closed, and I could put a firebrick on the front to keep the heat in.
 
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It would probably be easier to use the firebrick, but do you think it would be as efficient as the wool/refractory in the green propane canister?

I would build a venturi burner to skip having to deal with the torch, but I don't have a propane tank to hook it up to, only propane canisters.
 
Most propane torches put out somewhere between 2000 and 5000 BTU. The highest output propane torch I've found is the MT245c MagTorch. In an Atlas Mini forge, it will successfully heat treat 1084 blades. You didn't show us which torch you have, but let me assure you that most torches will not be capable of this. Most smaller burners, such as an Atlas Burner or a sidearm burner using a .023 mig tip will output 30000 BTU. When using a burner, a regulator is usually required to control it. Wide open 30000 BTU in a small forge is far too much heat to heat treat with.

Sorry, I just noticed you linked to a TS3000. The TS3000 is rated for 1460w or 4981 BTU. However, when I tested is beside an MT245c at 5000 BTU was that it was a little more than half the output. I would estimate it at around 3-4000 BTU. If your forge is well designed, it should work for 1084.

Here are links to 5 popular burners. They range in price from $60 with a regulator to $170 without a regulator. I have personally used both the Atlas and the HighTempTools and find them to be very similar in performance. I've never used or seen any of the others..
http://www.atlasknife.com/atlas-30k-burner
http://www.hightemptools.com/burners.html
http://zoellerforge.com/flare.html
http://www.hybridburners.com/new-ordering.html
http://www.chileforge.com/NewDiablomainPage.html
 
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Actually, I did link to the torch in the first post.

Going off of what was in that video though, it looks like it's entirely possible to heat treat with a normal torch. Should I still just skip trying to use the torch and send it out for heat treat?
 
Yes, I adjusted my post. For a first knife, I would send it out for heat treatment, or find someone nearby who is willing to help. There are a LOT of knifemakers within a couple hours of you.
 
Okay, so if I wanted to experiment with this torch, do you recommend the firebrick or lining a green propane canister with the insulwool and refractory?

Like I said before, I want to do this myself if at all possible. That said, if my torch thing doesn't work, is there any easy way of finding someone near me who can help heat treat?
 
Fire brick will work fine. Google 'son of the two brick forge'. It is a very good build of a 2 brick forge. I built one when I started and it worked good on smaller blades where the entire blade fit in the hole.
 
I built a small 2 brick forge and use the Atlas burner. It gets to ht temp extremely quickly. I tried using multiple torches in the forge at first. My torches weren't very good, they got the forge hot, but didn't distribute heat well at all and felt dangerous juggling all that crap. I suggest getting the right stuff the first time. If you don't have the funds to get a proper burner, try the torch. It may work fine for a few knives, but if you start spending money, get an Atlas burner.

Sounds like you are where I was at. You want to do it yourself, I can respect that. I did end up wishing that I had just saved for proper stuff because I ended up spending twice as much as I should have rather than doing it right the first time. I need to take my own advice since I seem to keep making that same mistake. :D
 
Thanks a bunch for the links guys, I can't believe I missed those when researching this before making this thread. I'll follow the instructions zaph posted because that back opening makes more sense to me. I'll be able to get the materials in a week or so, and when I'm done with it I'll post a pic of how well it works with my torch.
 
Masterjuggler said:
Thanks a bunch for the links guys, I can't believe I missed those when researching this before making this thread. I'll follow the instructions zaph posted because that back opening makes more sense to me. I'll be able to get the materials in a week or so, and when I'm done with it I'll post a pic of how well it works with my torch.
Click to expand...

Yeah, I'd post pics of my forge but it looks nearly identical to the one in that thread. Mostly because I made mine directly from those instructions. :D

The refrac cement that some people struggled with finding in that thread can be found at Tractor Supply, but it's seasonal here. They've already taken it off the shelves because winter is over. I'd give em a call where you're at if they have a store near you. I don't believe that it's critical, but it does help kinda hold everything together, provides a more durable interior and helps with the allowing the flame to swirl so long as it's a smooth application.

Good luck and let me know if there's anything I can do to help.
 
I just finished hardening my knife (tempering now) and the forge seems to have worked pretty well. The ts3000 was probably hot enough to heat treat with, but it was pretty slow. I stuck another cheap brass torch right next to it and the inside of the forge got more than hot enough. I drilled the hole for the torch a little bit too large, but it worked out because it let me stick two torches through the same hole (yes I realize what that sounds like LOL).

I found that not having the torches go into the hole, but stay just outside of it let the flames inside the forge get hotter because the propane flow from the torches forced more air into the forge to combust.

One thing I would change though is to put the torch hole at the front of the forge like in Gough Custom's video. The flame at the back forces me to shove the blade into the forge pretty far, and the tip gets heated up too fast. Later I'll make a brick powder and cement paste to fill the hole so I can make another one at the front.
 
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