Seirei Posted September 20, 2018 Share Posted September 20, 2018 Hey everyone, Hopefully this is in the right place. I am brand new to blacksmithing and recently finished building my first forge. I've run it a couple times now and I've noticed it doesn't seem to be getting quite hot enough however. It's a pretty standard build: 10" length, 6 1/2" inside diameter, two 1" layers of Kaowool coated with rigidizer and two coats of Satanite. The floor of the chamber is a hard firebrick with Kaowool under it and a coat of Satanite over it. The burner is a Mathewson that is currently sitting towards the top of the first layer of kaowool (near the body of the forge). I'm currently working on lowering the burner to allow the flame to he at more effectively and I've been using hard firebrick inside and to serve as "doors" for the forge. Pictures of my build are attached. My issue is that I can't quite seem to get the heat up to proper forging temperatures. I've run it several times now and have turned the PSI all the way up to 30 with no noticeable increase in temperature. The image of it running is at 30 PSI when it had been running for about 10-15 minutes or so. The stock pictured had been sitting in there for about 5-10 minutes at the time of the image and had been heated and worked a few times. Just starting out, I've primarily worked with some rebar and steel rod to work on the basics a bit but it has typically cooled to a dull cherry by the time I've turned around and gotten a few strikes into it. As I said, I'm working on lowering the burner a bit and plan to have it sit between the two layers of kaowool (about an inch or so from the chamber). My boss who has been my blacksmithing guide recommended using soft firebricks as well since the hard can soak up the heat rather than insulate properly. Any other tips or recommendations to better heat the forge are greatly appreciated! Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted September 20, 2018 Share Posted September 20, 2018 The only thing (other than the hard brick heat sink) that jumps out at me is that your burner seems to be aimed right where the floor meets the wall. If you could aim it at the near side of the floor (the side closest to the burner) or up on the wall a bit that would help induce a swirl effect which could have a positive effect on your issue. It appears as though the burner itself is putting out pretty good heat, but it's not staying in the forge as long as you'd like. Other than changing the aim, maybe try to block off a little more of the opening. That hard fire brick floor should make it take longer to come up to temperature, but I don't think it should have a big impact on the maximum temperature you can achieve. If the colors in the picture you posted are accurate, that's a pretty good forging temperature. The smaller the stock the faster it will cool off. Also don't expect to get the working time per heat that you see some experienced smiths achieve. The more you move the steel with your hammer strikes, the more that adds heat to the steel. Some guys can take room temperature steel to red hot just by hammering it - in small diameters or cross sections. Also, the anvil and hammer will suck heat out of the stock quickly if they are in contact with it for long. You may have seen some smiths kind of rock the stock up and down a bit to minimize anvil contact between strikes. Try to get a good swirl going in that forge and block off a bit more of the opening before dropping the burner lower or making any other significant changes - unless you're willing to get rid of that hard firebrick floor. Quote Link to comment Share on other sites More sharing options...
MotoMike Posted September 20, 2018 Share Posted September 20, 2018 Maybe a kiln wash of Plistix on the forge and the fire side of your doors? couldn't hurt. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted September 20, 2018 Share Posted September 20, 2018 Plistix will help with the radiant heating. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 21, 2018 Share Posted September 21, 2018 If there's wiggle room in the mount you can maybe adjust the burner's angle closer to what Buzz suggests and see how it works for you. I like a vortex in a cylindrical forge as he describes for the same reasons. Plistex or Matrikote are high alumina kiln washes that not only increase the amount of IR radiated back into the forge chamber but are pretty impervious to the kind of high temperature chemical erosion common in propane forges. Not just welding fluxes which are very caustic at high temp but just the propane flame is very chemically active. A good coat will do it good. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
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