How much LP does a small forge burn

[HuffHK]

Hello all,

I'm thinking about putting together a small gas forge as building one does not seem to be too difficult thanks to all the good info in the tutorial/sticky section. Assuming around 300 cubic inches lined with at least 1" wool and refractory how much propane does one go through on average? Also how much of a difference does ITC-100 make?

Is there any efficiency difference in a venturi vs forced air/blown burner? From what I can tell the main advantage of blown is that you have complete control over the air/gas ratio so can control temps more effectively. Venturi burners are nice in the fact that you don't need anything other than the fuel (ideal for places with no electricity etc).

I'm in Hawaii and propane runs about $8-9 per gallon so I'm trying to get a realistic estimate on what my operating costs would be. How long does a 20# tank last in a forge like this?

Thanks for the advice.

 

[Stacy E. Apelt - Bladesmith]

A small forge is very efficient if it has a good burner. The modern venturi burners from folks like Ron Riel are very good. Zaph makes a good small burner, too. If you are going to do HT in it, then I would suggest you make a blown burner. For general use and forging, the venturi works fine, and does not need electricity. For HT you need to be able to run the burner much lower, and also adjust the chamber atmosphere. That is where a blown shines and a venturi fails.

I find blown burners easier to run, and very efficient. I can't say I have ever seen a burn rate chart or comparison on rates of fuel use. On a small forge, the propane use will not be a big issue. I would suspect a properly tuned forge will use about a 5 gallon tank every 20-30 hours of normal burn time ( depending on how hot you run it, if you shut it down when not actually forging, and how big the forge and burner is, etc.). that works out to something around $2 per hour.