Couple questions on forge build

Sean Jones

Well-Known Member
I'm back to working on a forge build very similar to the one that Gliden07 is building. Here's a photo of where I am at.
69257

Now I'm at the point where I need to either find someone who can weld my project or as an alternative use JB Weld Exteme Heat for the bungs and also likely for the legs. Though I'm hoping I can use bolts.

So would the JB Weld extreme heat work? I don't know anyone personally who has a welder I can use, so I'd have to pay someone. I have no idea how much they would charge. But the JB Weld would certainly be less expensive if it's doable.

Also, are these tubes for the burners long enough?

And finally how far from the forge itself should the propane tank sit? I purchased one of Harbor Freights little red carts, the two shelf kind. My propane tank is taller than the top shelf so my plan is to cut an opening in the top shelf of the cart for the propane tank. The tank itself would sit on the bottom shelf. This would mean the valve would be within about 12" of the forge. Is that too close? I don't want a propane tank exploding from ambient heat!
 
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EdCaffreyMS

"The Montana Bladesmith"
So would the JB Weld extreme heat work?
Unfortunately.... no. It difficult to explain the heat your dealing with in a forge application.....it's intense, and long in duration. I can't even imagine any adhesive that would hold up to the heat.

are these tubes for the burners long enough?
The "tubes" only need to be long enough to hold the burner pipe(s)..... the heavier gauge, the better they will hold up to the heating/cooling over time.

the valve would be within about 12" of the forge. Is that too close?
While there is no set distance.... Personally I'd want the tank as far away as practically possible. It's not just the radiant heat from the forge.... when forging hot scale and pieces of hot steel get loose and fly around..... even a small piece of scale (smaller than a dime) can land on the propane line (if it's the rubber variety) and burn through.

If you're going to start forging, you're going to need a welder more and more. This is a perfect excuse to buy another tool! :) Even a cheap welder is better than none at all. I can't believe I'm saying this.... but Harbor Freight has a 110V wire feed/flux core welder for $120. It would take several overlapping passes with that welder to hold anything....but it's better than nothing. There are a number of welders listed for under $200.
 

Sean Jones

Well-Known Member
Unfortunately.... no. It difficult to explain the heat your dealing with in a forge application.....it's intense, and long in duration. I can't even imagine any adhesive that would hold up to the heat.


The "tubes" only need to be long enough to hold the burner pipe(s)..... the heavier gauge, the better they will hold up to the heating/cooling over time.


While there is no set distance.... Personally I'd want the tank as far away as practically possible. It's not just the radiant heat from the forge.... when forging hot scale and pieces of hot steel get loose and fly around..... even a small piece of scale (smaller than a dime) can land on the propane line (if it's the rubber variety) and burn through.

If you're going to start forging, you're going to need a welder more and more. This is a perfect excuse to buy another tool! :) Even a cheap welder is better than none at all. I can't believe I'm saying this.... but Harbor Freight has a 110V wire feed/flux core welder for $120. It would take several overlapping passes with that welder to hold anything....but it's better than nothing. There are a number of welders listed for under $200.
That's what I figured. I'm for having a welder. I'm sure I will find many uses for one. My budget, what ever a budget is, is totally blown on shop equipment. But I'm learning more and more to not take the cheap way out. I'll check out the harbor freight one and also our local ads for a good used one.

I also have an alternative plan for the propane tank in case what I was proposing wasn't a good idea. I have a hand truck that I can put the tank on and keep it well away from the forge. I want everything moveable so I can forge outside and put it away when I'm not using it.

Thanks Ed
 

Owl

KNIFE MAKER
I agree with Ed on the welder.
For years I didn't weld and spent too much time finding unsatisfactory work arounds for projects.
About 7-8 years ago I finally bought a stick welder and after just a little instruction and practice I was doing OK.
A flux core mig welder is even easier to run.
You will be amazed at how many problems welding will solve for you.
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
The two little tubes on top look galvanized which is not good. Zinc fumes will make you sick. Tubes that thin will not melt but will warp and slump from the forge heat over time. Cheap black pipe schedule 40 from the local home store will work better. You can buy it in short pieces.

decent used 140 amp gas mig welders are for sale all the time on Craig’s list. I started MiG welding with a $100 Hf unit. Use what you gotta use. So you know, The cheap HF flux core MIGs splatter all over the place and usually don’t have enough amperage to get decent penetration on anything past 1/8” thick. Gas migs are easier to operate and produce a much cleaner and better weld.
Watch a few YouTube beginner videos and weld the crap out of every piece of scrap metal you have. A few hours practice running beads and you will be able to weld.
 

KenH

Well-Known Member
You're not planning to have the burners mounted directly on top and pointing straight down are you? Better to mount around the 10 o'clock position and pointing slightly toward the rear so the flame isn't pointed direct toward the metal being heated.

Old propane tanks make GREAT forge bodies - the 20 lb or 30 lb bottle work good. Most propane places should have all you want of condemned tanks free of charge.
 

J. Keeton

Active Member
I second the "buy a cheap welder" notion. So many options when you can stick metal together with a cheap 110 flux core.

This may give you some ideas:

I recently build a forge and cart. My propane generally sits on the ground or on the bottom shelf of this cart.


I brought in the burner at an angle tangentially to the 2'' thick Kao-Wool interior. (Looking for a swirl). My shell was an old air tank.




The handle on a hinge allows the cart to be moved around easily. (Wheels came off an old welding cart)






I've gone on to replace the burner with the one shown in the tutorial video below (I felt like a smaller burner gave me better "lower end" control for HT-ing 1084 in the forge). This burner can be built without the use of a welder.



Cheers,
JK
 

Gliden07

Well-Known Member
I'm back to working on a forge build very similar to the one that Gliden07 is building. Here's a photo of where I am at.
View attachment 69257

Now I'm at the point where I need to either find someone who can weld my project or as an alternative use JB Weld Exteme Heat for the bungs and also likely for the legs. Though I'm hoping I can use bolts.

So would the JB Weld extreme heat work? I don't know anyone personally who has a welder I can use, so I'd have to pay someone. I have no idea how much they would charge. But the JB Weld would certainly be less expensive if it's doable.

Also, are these tubes for the burners long enough?

And finally how far from the forge itself should the propane tank sit? I purchased one of Harbor Freights little red carts, the two shelf kind. My propane tank is taller than the top shelf so my plan is to cut an opening in the top shelf of the cart for the propane tank. The tank itself would sit on the bottom shelf. This would mean the valve would be within about 12" of the forge. Is that too close? I don't want a propane tank exploding from ambient heat!
Your gonna probably finish yours before I finish mine!!
 

EdCaffreyMS

"The Montana Bladesmith"
Something I see a lot of folks do....is build a round forge, then place the burner(s) in such a way that the are pointed directly at the work area/piece. The whole idea behind a round design for a forge is to achieve a "swirling" flame, that heats the steel indirectly. It's a more gentle heat of the steel, but because of the "swirl" of the flame, the temp is much more even and controllable.......



In the below image, I had just fired it up (less than a minute before I snapped the pic), and you can see how the flame is following the interior curvature of the forge....... if you look at where the burner enters the exterior wall of the forge.....you can see what I'm trying to rely in the first image/drawing.



If you're building a round design forge, and not placing the burner at a tangent.... so the flame follows the inside contour, you might as well build a square forge..... not trying to be mean by saying that, just stating the facts.

Rather than cut and weld the burner holders at a 90 degree...... you need to cut/grind the rough exterior contour on the burner holder(s) end(s) that you intend to weld/affix to the forge body.....then position/weld the burner holder(s) in such a manner that if forces the burner/flame to follow the inter contour of your forge (you can use a piece of smaller pipe run through the burner holder(s) and to the interior of the forge to give you a close approximation or where the actual burner will go....... here's a example of how I did it on my welding forge.....only difference is my welding for is vertical. It's just as easy to do it on a horizontal design.

 
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Chris Railey

KNIFE MAKER
I have the HF cheapo flux core welder. Its good on small stuff but I discovered that if I need to weld bigger stuff I pre-heat it dull cherry with my torch then hit it with the flux core. I am no welder but it holds. You can find them used on CL for $50. Its a decent work around until I can get a better welder.
 

Sean Jones

Well-Known Member
The two little tubes on top look galvanized which is not good. Zinc fumes will make you sick. Tubes that thin will not melt but will warp and slump from the forge heat over time. Cheap black pipe schedule 40 from the local home store will work better. You can buy it in short pieces.

decent used 140 amp gas mig welders are for sale all the time on Craig’s list. I started MiG welding with a $100 Hf unit. Use what you gotta use. So you know, The cheap HF flux core MIGs splatter all over the place and usually don’t have enough amperage to get decent penetration on anything past 1/8” thick. Gas migs are easier to operate and produce a much cleaner and better weld.
Watch a few YouTube beginner videos and weld the crap out of every piece of scrap metal you have. A few hours practice running beads and you will be able to weld.
They might be galvanized. I'm not sure. They're electrical conduit pipe. I'll look for schedule 40 black pipe and replace them just to be safe. Thanks. I have no interest in getting sick.
 

Sean Jones

Well-Known Member
You're not planning to have the burners mounted directly on top and pointing straight down are you? Better to mount around the 10 o'clock position and pointing slightly toward the rear so the flame isn't pointed direct toward the metal being heated.

Old propane tanks make GREAT forge bodies - the 20 lb or 30 lb bottle work good. Most propane places should have all you want of condemned tanks free of charge.
I put the tank in that position for the photo. I was planning on putting them at about the 10 o'clock position. I didn't know about pointing slightly to the rear. I'll take that into consideration when they get welded.
 

Sean Jones

Well-Known Member
I second the "buy a cheap welder" notion. So many options when you can stick metal together with a cheap 110 flux core.

This may give you some ideas:

I recently build a forge and cart. My propane generally sits on the ground or on the bottom shelf of this cart.


I brought in the burner at an angle tangentially to the 2'' thick Kao-Wool interior. (Looking for a swirl). My shell was an old air tank.




The handle on a hinge allows the cart to be moved around easily. (Wheels came off an old welding cart)






I've gone on to replace the burner with the one shown in the tutorial video below (I felt like a smaller burner gave me better "lower end" control for HT-ing 1084 in the forge). This burner can be built without the use of a welder.



Cheers,
JK
Thanks for the input. My shell is an old air tank also. The burners I have came from Atlas Forge as well as the hoses and regulator. However I'm glad I saw your setup. I need to rethink some parts of how I'm doing mine.
 

Sean Jones

Well-Known Member
Something I see a lot of folks do....is build a round forge, then place the burner(s) in such a way that the are pointed directly at the work area/piece. The whole idea behind a round design for a forge is to achieve a "swirling" flame, that heats the steel indirectly. It's a more gentle heat of the steel, but because of the "swirl" of the flame, the temp is much more even and controllable.......



In the below image, I had just fired it up (less than a minute before I snapped the pic), and you can see how the flame is following the interior curvature of the forge....... if you look at where the burner enters the exterior wall of the forge.....you can see what I'm trying to rely in the first image/drawing.



If you're building a round design forge, and not placing the burner at a tangent.... so the flame follows the inside contour, you might as well build a square forge..... not trying to be mean by saying that, just stating the facts.

Rather than cut and weld the burner holders at a 90 degree...... you need to cut/grind the rough exterior contour on the burner holder(s) end(s) that you intend to weld/affix to the forge body.....then position/weld the burner holder(s) in such a manner that if forces the burner/flame to follow the inter contour of your forge (you can use a piece of smaller pipe run through the burner holder(s) and to the interior of the forge to give you a close approximation or where the actual burner will go....... here's a example of hold I did it on my welding forge.....only difference is my welding for is vertical. It's just as easy to do it on a horizontal design.

Thanks Ed. I'm really grateful for all the help on this. While I researched a lot of this months ago, this project has been going on sporadically and my research, on this part in particular, seems to have gotten a bit vague over time. And I didn't think that large an angle would be necessary. That looks like about a 30 degree angle?
 

Sean Jones

Well-Known Member
I have the HF cheapo flux core welder. Its good on small stuff but I discovered that if I need to weld bigger stuff I pre-heat it dull cherry with my torch then hit it with the flux core. I am no welder but it holds. You can find them used on CL for $50. Its a decent work around until I can get a better welder.
I've been looking and I've seen a few in the less than $100 range. I'll continue to look around and see what I can find.
 

EdCaffreyMS

"The Montana Bladesmith"
that looks like about a 30 degree angle?
I'm not really sure Sean....but I suspect that's close. It's kind of an abstract thing...in that you have to be able to image the angle needed....so that the flame will be forced to follow the inside contour. It really does make a "night and day" different in how a round forge performs versus having the burner(s) pointed straight in.

Another thing that I am a big advocate of is using a single burner (properly sized) versus multiple burners. People think that multiple burners will give them more heat, when in reality they usually just end up fighting a multiple burner set up, and the burners usually work against each other...... there are so many issues with getting multiple burners to work in unison, versus against each other...... that I could write a book on it. Suffice to say that a properly sized single burner will far out perform multiple burners, use less fuel, and be far easier/simpler to tune/adjust then any multiple burner arrangement. ;)
 
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Sean Jones

Well-Known Member
I'm not really sure Sean....but I suspect that's close. It's kind of an abstract thing...in that you have to be able to image the angle needed....so that the flame will be forced to follow the inside contour. It really does make a "night and day" different in how a round forge performs versus having the burner(s) pointed straight in.

Another thing that I am a big advocate of is using a single burner (properly sized) versus multiple burners. People think that multiple burners will give them more heat, when in reality they usually just end up fighting a multiple burner set up, and the burners usually work against each other...... there are so many issues with getting multiple burners to work in unison, versus against each other...... that I could write a book on it. Suffice to say that a properly sized single burner will far out perform multiple burners, use less fuel, and be far easier/simpler to tune/adjust then any multiple burner arrangement. ;)
Thanks for the reply Ed. I'm going to give your suggestions some serious thought. I get the part about that angle being somewhat abstract. That makes sense. I'm going to take a step back from this whole project for a bit and think things over. I do have my little coffee can forge for now which has actually worked fairly well for small knives. But it's going to come apart on me one of these days. Probably when I need it the most.

I hate to abandon this direction (particularly with what I have invested in parts), but at the same time I've learned from my IT days the sooner you fix or change a procedure the less headaches there will be in the long run.

Maybe I'll just bite the bullet and get an Atlas Forge.
 

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
You can set it up for two burners and still just use at a time with a simple shut off valve. If you do use two, you have to move your steel back and forth constantly to avoid over heating one area and even then you will have heated a much larger area to hammer than you would like to. I have a two burner and I hate it for anything other than heating billets of damascus. I use one of the single burner forges most of the time.

Don't buy a finished forge when you almost go this.
 

Sean Jones

Well-Known Member
Thanks for the input Tracy. I forget that you can close off one burner, or at least I think I can. I have a split hose from Atlas Forge made for their two burners. But I could probably put a shut off valve in front of one without to much trouble? I'll investigate that.
 

Doug Lester

Well-Known Member
A deeper forge can be handy when it comes to heat treating but if you are using it for smithing you can really only work about 4"-5" of your stock at a time. No real sense in heating more than that in forging a blade.

Doug
 
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