One brick forge - can it be used for anything but heat treating?

S

SteelGrinder

Joined
Jan 15, 2006
Messages
3
Allright, I am a newbie when it comes to propane forges.
I've been using coal an charcoal from the very beginning. Never built a propane forge, never used one too.
I decided to give them a try and build a small forge. Most probably a one-brick or a coffee can forge.
Then I read that propane forges barely reach welding temperature and that the small ones barely reach critical!

My question is: since many people complain about gas forges in general being too low-temp for forge welding and since most people doing Damascus prefer charcoal, is there any use of those small one-brick forges? Yes, I know that they can bring a piece of steel to critical but that is just too... useless, when it comes to forging and especially forge welding.
I want a small forge that can reach orange-yellow forging temp for making small knives like folders and the such. Or even better - one that can reach welding temperature.

If the majority of big propane forges cannot reach welding heat, then why do people build even smaller miniature one-brick forges?! Just to use them for heat treating of short blades?
Or am I missing something and is there any real use of those?

Anyone had any success reaching forging temperatures with a one-brick forge?

Thanks!
 
one brick forge is just for bring to non magnetic on simple crabon steels and thats about it. people use it just like i did when i started because it cheap and easy. i ran into problems very quickly though with this set up.The surface area inside a 1 brick forge is very small and it gets very hot very fast. as in to hot. once i got a pyrometer is was a shocker just how fast it heated up. I have since made a mini forge that has a 4 inch diameter inside. i dont do forge welding or damsacus with this. just last night i did a heat treat on a 01 blade and with a small 1 1/2 diamtere stainless steel pipe inside forge i was able to easliy control the temp to within a few degress. Also with just a 1 turn of the valve on mapp gas i was over 1700 for the warm up and had then i back it down to my heat treat temp and let it stablize. talk to Mr. ellis and check out his refactory website i do believe that venturi or forced air propane easily reaches welding temps.
 
Thank you for your answer, Dakota.
Yes, seems that I got a ton of misinformation and that caused my confusion. Now I know that forced air propane forges do get to welding temperature easily.

About the one brick forge:
Too hot sounds like good news - this is what I am loking for. :)
Or I may be just mistaken again. :foot:
 
Too hot, as in, too hot in this spot - not hot enough in another spot.
One brick forges are for those who can't get a piece of metal heated up by any other method,and can't yet afford to build a proper forge.Running on propane,an atmospheric burner will easily get a small forge up to 2200F and a blown forge will reach 2700F.A good size is an old freon or propane tank.By the time you insulate it right it will have a 6" round chamber.A pyrometer is a real good idea,too.No point being able to get something hot,unless you have a good idea of how hot it is.There are a bunch of forge plans on the knifehow site - www.knifehow.com .
Stacy
 
I have ben using a small LPG as we call it first at a mates place and now have built 7 for myself and others. Venturi effect or 6 hole burners, never forced air. You don't need it on small units.

I have one made 16 inches long and 10 inch diamiter for welding. The bottom half is full of cat litter and fire brich to protect the lining from the borax flux.

16 inches equals a huge blade particularly if you work one half at a time that is you can end up with something close to double the length.

A good size for the hobby maker beginner is 12 inches by 8 inches same thing end for end the billet and you get a big blade.

I allways make them with a back wall so that the inside chamber heats evenly. If you want you can leave both ends open and the you can make a blade as long as you want. If you don't have machines you can only work a limited section before it is too cold.

get yourself a mate with a sledge hammer if your going to start on damascus.
you can make it yourself but 2 of you is more fun. Have falf each or 2 billets.

back to basics the one brick forge can be used to make small blades to get you started. A larger one is more expensive but more useful.
 
I've got a one brick forge using propane, and can't heat treat blades that are 8" long due to lack of even heat. I was thinking of building a forge with a 3" hole in the middle and a side arm burner. Should I avoid those, and go with forced air? Or are they good enough to do the job for heat treating? I'd like to be able to heat treat a 12" blade.
 
Larry Zoeller sells parts for sidearm burners. http://www.geocities.com/zoellerforge/
In conversations with him he said one 3/4" sidearm burner will heat 300cu.in. to welding heat. I've found references saying this burner will reach welding heat in a 350cu.in. forge.

A friend and I built a horizontal forge 6" dia. x 24" (678cu.in.) with 3 - 3/4" sidearm burners. Turns out we only need to run the front and back burners for welding and forging.

A 4" dia. x 16" forge is 201cu.in. One of the 1/2" sidearm burners would run this forge to welding heat, I believe. 5" dia. x 16" forge is 314cu.in.

Larry's site is full of information and my experience is Larry is a very willing and helpful person.

If you want a brick forge, Wayne Goddard's article in Blade's knife making book shows his "two brick" design. It is one and a half bricks long and the half brick has a hole in half it's depth. That makes an 11" chamber. I built one and use it for forging and heat-treating. A person needs to learn the forge's characteristics to heat evenly for heat-treating. I can't hold a blade in one position and get an even heat and I can't run the Bernzomatic JTH-7 full tilt and get an even heat. Other forges may be easier to work with but a "two brick" works well. I've got $36.50 and some time in mine. Wayne Goddard is a very helpful person. When I first contacted him about his "two brick" forge I appologised for bothering him with questions. He said, "That's what I'm here for".
 
I've had some pretty good luck with my one brick forge and a mapp gas set up....
I'm pretty sure it's reaching welding heat but like others have said... its pretty much for small stuff....
Here's some pics I took for some friends... with basic stuff to show them how easy it was to get started.... that's a 5/8 coil spring I'm straightening.... sorry for the quality... you'll get a good idea of the color you can reach...
 
I use a two brick forge design but then again I am not making anything other than small knives and on a limited budget. There is a post on Britishblades with info on building the 2 brick forge. For what I need it is fine and seems to heat up well enough.

I won't be able to do anything much larger than a 4 inch blade or so but thats all I need it for right now. If I even get to making something larger then I plan on making a larger forge (if I can afford a decent burner ;))
 
You must log in or register to reply here.
Back
Top