thinking about building a gas forge

[Zane Thompson]

howdy,

lately I've been thinking about building a propane forge but before I start I thought i'd better check and make sure I was on the right track.

first, is a smaller forge more efficient than a larger forge? common sense would say yes but what do I know lol. originally I was planning to use an old propane tank or a 5 gallon air tank for the forge body but got to thinking they may be larger than I need right now. I have some 8" wide  pipe  and I think some 6" or 8"  wide tubing that might be a better starting option for me.

 

second, not having any experience with burners i'm having a hard time deciding what would be best one to use. atlas forge sells a 100k btu burner with a 30 psi regulator for around 70 bucks which looks like a good option. and I was also thinking about the venturi burner kit from high temp tools. by the time I got that and then a regulator i'd be looking at about $80 to $100. another option I just discovered here on the forum is the turkey fryer burner. looks like I could get a burner and regulator combo on amazon for around $30.  any suggestions on what to go with?

 

third,  if I did go with the 8" pipe for the forge body would 2" of inswool coated in satanite be a good combo? or is there something better?

 

my main interests right now are 10" to 15" Bowies and fighters and eventually trying my hand at Damascus so i'd like to build a forge that could handle all of that without being overkill.

 

thanks in advance!

Zane.

 

 

Edited September 19, 2019 by Zane Thompson
added some info

[Wayne Coe]

Check out the Build a Gas Forge and the Ribbon Burner attachments on the Forge Supplies page at www.WayneCoeArtistBlacksmith.com.

Let me know if I can help you.

[Daniel W]

A piece of 8in diameter pipe would be a good start.  That will give you 6in of working space in the forge.

I used a section of 9in diameter pipe, for my work, which if I was making just knifes would be more than what I would ever need.  However if you venture out into making decorative items, Wayne's clam shell design looks like a better option.  Its just more versatile for working really bigger and more complicated shapes.

Just know for burners, if you happen to build your own, expect to spend a lot of time trying to figure it out. If you buy one, you just have to tune it to run correctly. 

[Alan Longmire]

The turkey fryer burner may or may not get you to welding heat, and you might need to add some length to the mixing tube.  There are hundreds (well, dozens, anyway) of threads on forge building and burners here, including at least three pinned ones.  Read the pinned ones all the way through (not just the first couple of posts), because they are cumulative.  To find the others do a focused google search by typing your search term in the google search window followed by site=www.bladesmithsforum.com and you'll get a much better results list than by using the built-in search function.

[Joshua States]

12 hours ago, Zane Thompson said:

my main interests right now are 10" to 15" Bowies and fighters and eventually trying my hand at Damascus so i'd like to build a forge that could handle all of that without being overkill.

Those are big blades, by most standards, unless that length includes the handle. 

The one size fits all forge works for some folks and not for others. Generally speaking, most tool steels used for blades are not forged at welding heats. So, if you want only one forge, it needs to be easily adjusted between say 1600*F and 2400* F.  This is not as simple as just turning up or down the psi on the regulator. Gas/air mixtures need to be redone to avoid decarb and scale production. It gets to be a lot of fiddling sometimes.

Over the years I found myself changing my forge around a number of times. I think a lot of us have done this. I now have a dedicated welding forge for my Damascus work, with a blown ribbon burner, and sometimes use a venturi type burner forge for general forging. I have my welding forge set up so that I can easily reduce the gas flow and a couple quick turns of the air valve will make it settle out to regular forging heat. I do this when reducing stock that doesn't need welding heat, but I want it to come up to heat quickly. (I use a lot of 1 inch drill rod or big hunks of W-2 as blade steel)

My advice is this. If you are new to the craft, make a general purpose forge that will get you to forging heats for the steels you use. When you feel confident in your forging and want to move to Damascus and forge welding, build a ribbon burner. I posted some easy instructions in the Tools and Tool making section.

[Zane Thompson]

8 hours ago, Wayne Coe said:

Check out the Build a Gas Forge and the Ribbon Burner attachments on the Forge Supplies page at www.WayneCoeArtistBlacksmith.com.

Let me know if I can help you.

 

Thank you Mr. Coe, will read them as soon as i get to my computer.

 

 

6 hours ago, Daniel W said:

A piece of 8in diameter pipe would be a good start.  That will give you 6in of working space in the forge.

I used a section of 9in diameter pipe, for my work, which if I was making just knifes would be more than what I would ever need.  However if you venture out into making decorative items, Wayne's clam shell design looks like a better option.  Its just more versatile for working really bigger and more complicated shapes.

Just know for burners, if you happen to build your own, expect to spend a lot of time trying to figure it out. If you buy one, you just have to tune it to run correctly. 

 

Thanks Daniel, i was thinking the pipe would be my best bet right now.

 

2 hours ago, Alan Longmire said:

The turkey fryer burner may or may not get you to welding heat, and you might need to add some length to the mixing tube.  There are hundreds (well, dozens, anyway) of threads on forge building and burners here, including at least three pinned ones.  Read the pinned ones all the way through (not just the first couple of posts), because they are cumulative.  To find the others do a focused google search by typing your search term in the google search window followed by site=www.bladesmithsforum.com and you'll get a much better results list than by using the built-in search function.

 

Thanks Alan,  i'll scrap the turkey fryer burner for now and go with something else.  

 

 

1 hour ago, Joshua States said:

Those are big blades, by most standards, unless that length includes the handle. 

The one size fits all forge works for some folks and not for others. Generally speaking, most tool steels used for blades are not forged at welding heats. So, if you want only one forge, it needs to be easily adjusted between say 1600*F and 2400* F.  This is not as simple as just turning up or down the psi on the regulator. Gas/air mixtures need to be redone to avoid decarb and scale production. It gets to be a lot of fiddling sometimes.

Over the years I found myself changing my forge around a number of times. I think a lot of us have done this. I now have a dedicated welding forge for my Damascus work, with a blown ribbon burner, and sometimes use a venturi type burner forge for general forging. I have my welding forge set up so that I can easily reduce the gas flow and a couple quick turns of the air valve will make it settle out to regular forging heat. I do this when reducing stock that doesn't need welding heat, but I want it to come up to heat quickly. (I use a lot of 1 inch drill rod or big hunks of W-2 as blade steel)

My advice is this. If you are new to the craft, make a general purpose forge that will get you to forging heats for the steels you use. When you feel confident in your forging and want to move to Damascus and forge welding, build a ribbon burner. I posted some easy instructions in the Tools and Tool making section.

 

Thanks Joshua, on the blades i meant OAL, short swords will come later lol.  i wasn't aware you could have that much control over the temperature in a gas forge. I just assumed you let it run and pull out your steel when it reached 1800 F or so. good to know.   Right now i just want to build something simple and once i get the hang of things i can always build another one that would better suit my needs then.

[Jeremy Blohm]

As for the turkey fryer I have attempted to weld in it a few times without success. It does ok for a general forging burner if the chamber is small enough and not made of the hard brick I made the first one with. So far the few that I made I gave to friends and they are still using them and I have 2 more burners that in going to do some more experiments with one will be a small furnace for melting copper. I'm really curious about the furnace attempt.

[Alex Middleton]

I built my forge and burner based on this design:

The only thing I added was a gate valve for adjusting my air flow.  It was very simple to build and, like Josh said, being a blown burner it's easily adjustable.

[Andrew W]

Alan recommended the burners from anvilfire.com ( https://www.anvilfire.com/21centbs/products/P-75/ ) the last time this thread came up, and I have only good things to say about them. They've made forge welding effortless, and they're relatively inexpensive.

I lined my forge with 2" of inswool and 1/4" of kastolite, with some extra bubble alumina on the floor since I tend to throw a lot of corrosive things into my forge (lots of borax and slag from bloomery iron). I bought all these from hightemptools.com ; not the absolute cheapest supplier, but they had everything I wanted in one place and I didn't have to worry about accidentally buying the wrong product.

[Doug Lester]

Just remember when sizing up your forge that you can only realistically work up to 4"-5" of steel at a time and you can heat treat a blade that is longer than the forge is deep if you have a pass through port on the back side.

Doug