Forge Hot Spots

MarcWeitz

Member
I'm new to blade smithing and will have to build my own forge. I hope I'm not overthinking this... It seems Blade Smiths who understand their forge know where the hot spots are and the workaround to deal with it. When constructing a new forge I've seen the venturi's placed at offset angles, and at vertical placement. If offset angles are used - why do so many commercial gas forges place them vertically?
 

Chris Railey

KNIFE MAKER
More than likely because it is easier to make them that way. In general blacksmithing it can be an advantage to only heat the small section of steel you are working on and in that case vertical burners may help. If you intend to make knives only I would mount them at an angle for sure.
 

Smallshop

KNIFE MAKER
Marc...Ed Caffrey has built forges and is on this site. Search him and go to his website...a bunch of great stuff there AND here...his stuff is fun to watch...super knowledgeable/nice guy. He is a master smith.
 

MarcWeitz

Member
Thanks Chris - I'm thinking you're right about it being easier for manufacturers to do it that way. I guess no matter which way it goes "hot spots" are unavoidable in forges ..i don't know...just didn't want to build one and have to factor a situation that would complicate the learning curve.

Marc...Ed Caffrey.....
Thanks Ted - yeah, read a lot of his posts...probably should address him directly.
 

Chris Railey

KNIFE MAKER
My current forge has vertical burners and when I build another one it will have angled burners. The angle is not that important the goal is to simply maker the heat swirl around so to speak so it heats more evenly.
 

Sean Jones

Well-Known Member
Most likely because vertical is easier. I'm in the middle of building a forge myself. Ed Caffrey pointed out the advantage of angled burners to me and my intention is to have them angled.
Do some poking around here and you will find a lot on this topic, as well as Ed Caffrey's site that Smallshop mentioned.
 

EdCaffreyMS

"The Montana Bladesmith"
If offset angles are used - why do so many commercial gas forges place them vertically?
One word..... PROFIT! It's far less time and labor intensive to build forges with burners set at 90 degree angles. To me it also indicates that the company designing/offering a given forge doesn't have a clue about forging or how a forge should operate.....they're just interested in the $$$$. (In the current FIF era, the same holds true with many other Bladesmithing/Knifemaking tools..... there are a ton of people and companies who've jumped on the bandwagon, hoping to make a quick buck, offering everything from forging hammers to grinders.......without a clue as to what they are building/offering)

There's a reason that most experienced Bladesmiths build their own forges is because there really isn't a well thought out, well designed, Bladesmithing forge produced/available commercially. There are a few that come close.....but even those models fall short as far as burner placement is concerned.

Just a quick primer on what most full time/Professional Bladesmiths tend to look for in a forge...

1. Round in design
2. A SINGLE, properly sized burner, for the forge size
3. If the Bladesmith has only a single forge in their shop(s), it's usually a "blown" burner design. (that way the forge can be used for everything from general forging to forge welding) Personally, I have 3 forges, 2 of which are used most of the time......a single burner/venturi forge, with ceramic fiber lining that is used for general forging, and NEVER sees any type of flux. The second is a vertical welding forge that I describe in this WIP: http://www.legacystudioproductions.net/knifemakertraining/blog/page/3/
4. A burner that is inserted in such a manner as to force the flame pattern to "swirl" along the ID of the forge, and avoids the burner flame being directed at the work piece(s).
5. And likely the biggest "trade off" choice for a forge...... castable versus ceramic fiber insulators. Each has their pros and cons.

There are also other aspects that will vary based on personal preference from Bladesmith to Bladesmith, but the most common attributes are those I listed above.
 
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MarcWeitz

Member
Thank you Ed. Glad to see you're up and check'n things out - I read on your site you were out for a bit. I'm pretty sure my first forge is going to be a smaller round gas forge with one burner, but I know without a doubt I'll find a legitimate need for a blown forge big enough for a crucible and billet. Thats a crazy cool knife with the Damascus plugs. I've seen some of the videos on your training site - thank you for deepening and broadening the body of knowledge...that's commitment to the art and science.
 

EdCaffreyMS

"The Montana Bladesmith"
Your very welcome Marc! Beside deeply enjoying the teaching aspect of Bladesmithing/Knifemaking, I also try to help others NOT make the same mistakes I have! :)
 

MarcWeitz

Member
Angled burner is the way to go apparently - I was fearing, after putting forth the effort, creating a significant hot spot without realizing or because of poor design. When you don't know - you don't know what to expect - and the folks on this forum are most constructively helpful. Time to quit reading and start doing.
Thanks all.
 
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