Forge building question

Rick Lowe

Rick Lowe

Joined
Jan 6, 2005
Messages
1,331
Been using a "one brick" forge to heat treat and learning to forge. It works well except for limitation on size. Went scrapping yesterday and came home with a rectangular case 12" long, 8" tall, 6" wide, 1/4" thick. Lining, legs etc. won't be a problem, but I wonder if this shape will be efficiant? Most of the forges I see are round (better swirl?). Should I round out the lining with a brick on the bottom? Solid back plate with door in front?
Rick
 
That should work just fine. Sounds very close to what my farrier uses for horseshoes. His is vented at both ends, with about a 1-1/2" square hole, and one of the long sides is a door that is hinged at the top. Think its an
NC forge if you want to google it and get some ideas.
If you make the openings in the end about 2" or 3" square it ought to have plenty of room to get blades in and out, and with both ends done you can run long blades clear through it.
I would probably use 2 small burners (you can plumb them together to run off the same regulator) to try and get more even heat since you can't get much swirl in the square box.
 
A tangential vortex swirl forge will have much more even heat without hot spots. Hot spots will pit your work thus creating more work. My first forge was rectangular and I will never build or use another one again. I think of all the hours and how many grinder belts I smoked trying to get rid of heat pits.
 
There were two very good threads here in the not so distant past that showed the development of forges by two younger guys. I would recommend you dig those threads up and look at how J. Keeton (Jimmy) went through three forges, one square, and finally arrived at a propane-tank forge which he stuck with. The first was too big, second too square, and third was just right. I thought it was an excellent thread, IMHO.

Search on "Peter R. Ryt" and "J. Keeton" and it may give you some good info. I hope it can help you some. :)

Edited to add: I realized some folks have hassles getting search to work. Here's the threads:

http://www.bladeforums.com/forums/showthread.php?t=374778&highlight=Keeton

http://www.bladeforums.com/forums/showthread.php?t=377055&highlight=Keeton

and one more http://www.bladeforums.com/forums/showthread.php?t=373899&highlight=square+forge
 
Found that thread and it is good reading. Very nicely done. Thanks Fitzo! After studying this a bit, I think rounding the interior top and sides will be the trick. My chamber will only be 2" wide by 4" tall and 8" long. With openings on both ends I should be able to work longer stock when needed. The plan is to still use the Benzo-Matic torch with a bigger propane tank and get more room and more efficiancy. What do y'all think?
 
Rick, one thing to pay heed to when you line it is the hole for the angle the burner will blow the flame into the forge so that it'll swirl. The best comparison I can give is putting water into a little kiddie splash pool. Hose it in straight and it splashes all over. Squirt it in at a sharp angle along the side and it swirls real nice. That's what one wants in a knifemnaker's forge, like Brent mentioned.

I'm thinking I'm probably preaching to the choir, but it's important enough to mention again.

Good luck! :)
 
I appreciate (and need) all the help I can get! Are you saying to position the hole so that the flame hits the opposing wall at roughly 90deg.? In my one brick it angles up in a more acute angle and it heats really good and even.
Rick
 
I don't know quite how to say it right, Rick. It's not shooting across to the other side. I'll try and draw a little pic. Hopefully someone can explain better than me.
 
Rick Lowe said:
I appreciate (and need) all the help I can get! Are you saying to position the hole so that the flame hits the opposing wall at roughly 90deg.? In my one brick it angles up in a more acute angle and it heats really good and even.
Rick
Click to expand...
Nope, he's saying you don't want it to hit the opposing wall at 90 degrees. You want it to hit at an angle so that it will swirl around the inside of the chamber. Sort of like skipping a rock across a pond.

The propane torch will probably work for the time being, but you really should think about making a burner for it in the long run. Its not very hard to do. There are about a million different designs out there that work. You can pick whatever you can get the parts for (mostly various pipe fittings) the easiest, or whatever will fit your forge the best.
 
Maybe this'll give an idea. Jeesh, I can't use CorelDraw for crap either! LOL I'm really hoping I'm not further confusing the issue. :( Sounds like your other forge is already doing what i was trying to say; "preaching to the choir", like I said! :)
 
Hi Rick, These guys are giving you great advice! I just wanted to post to see if you're going to Bill Wiggins hammer-in in two weeks over in Canton? ...I saw that you're pretty close by in Candler, N.C. :)

-Darren
 
Nothing wrong with your drawing Fitz. It looks good to me. That's about how mine is set up. I just made a wooden holder to keep the burner at the correct angle.
 
Just one more thing about the burner entry It need to run around the inside like drawn above bau tat the same time mine is angled towards the back of the forge. If your burner is at a tangent as drawn but at 90 degrees to the forge the swirl runs arouns on it self. If you pull the outside edge of the burner pipe forward 20 degrees from the 90 the flame swirles in a screw effect to the back again giving better het distrubution..

I have my round pipe half full of kiln shelf and kitty litter so I think realy only the roof and walls need to be curved the bottom can be flat.

Hope that makes sence.
 
Reg ELLERY said:
..If your burner is at a tangent as drawn but at 90 degrees to the forge the swirl runs arouns on it self. If you pull the outside edge of the burner pipe forward 20 degrees from the 90 the flame swirles in a screw effect to the back again giving better het distrubution......
Click to expand...

That's exactly how mine's drawn, Reg. You just can't tell because it's a 2-D drawing! It's not the spiral it looks like but a helix! Yeah, that's the ticket!!! :rolleyes: :rolleyes: :foot:

That's my story and I'm sticking to it! :D

Most excellent point, Reg. :thumbup: In all honesty I never even thought about it. I use a vertical forge and the flame has nowhere to go but up, and when one fires it up without the top on it's like a tornado coming out.
 
Thanks to all for the help. Gonna go with 1" wool, satanite, and itc-100 which will allow more chamber area. I follow the thinking on burner angle and getting the swirl. shouldn't be too hard to get that lined up. Floor will be flat and ceiling will be a curve. Just waiting for the materials from Darren.
Rick
 
i have a propane forge thats square on the inside. it has ceramic liner and i was wondering if it would be better if i put insiwool in it to round it out
forge.jpg

fotge2.jpg

thanks for any help
 
You would also have to redirect the burners to get it to swirl around and keep the heat even. I know that almost all commercial forges out there are rectangular but they are made mostly for horseshoers. The horseshoe is in the flame for a very short amount of time compared to a blade and the pitting is not an issue.
 
i could probly heat the tubes and bend them at an angle to get a swirl affect. where can i get the insulation and some satanite?
 
Rick,
I'm going to send you a cd in the mail if you will email your address.
I hope you reconsider using the propane torch you used in your 1-brick. Because you are going to a much larger interior volume, that torch will not get her done. Making your own is so very simple that once you've done it you'll wonder "why'd I ever......".
Be seeing you in a few weeks and I can walk you through the process.
Carl Rx
 
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