How long will a 20# tank run your forge?

Kentucky

Kentucky

Joined
Dec 13, 2008
Messages
2,985
Im just curious..First off I don't care for 20 pound propane tanks but it seems many guys use them..Id like to know if you were running at just forging heat how long would it last? and if your running at welding heat how long would it last? keep in mind mind Im asking with the assumption that your keeping the tank from frosting over too..
Ill start I guess. Our only gasser right now is a diamondback two burner blacksmith model. Solid forge,durable and will weld no problem(it will melt steel actually) but boy it enjoys propane:D(or at least I think it does maybe this will tell me Im wrong? hopefully) Id say running a 20# tank on ours at appx 7-8 psi it would last about 5-6 hours..At welding heat(12-15 psi) maybe 2..
Looking forward to your answers..:thumbup:
 
Here's a link to the BTU calculator on Ron Reil's section of the ABANA website.
The BTU calculator will tell you how long a certain size orifice will burn, given the PSI and orifice size. "Welding heat" varies greatly, depending on the specific burner, forge size, etc.
https://www.abana.org/ronreil/BTU_Calculator.xls
https://www.abana.org/ronreil/design2.shtml#BTU

Now, for a direct answer to the OP, an Atlas Mini Forge will burn at 12-15 PSI for around 14 hours, as indicated by the last three hammer-ins at USAKnifemaker.
 
One cannot discount the tank freezing up, especially at welding heat. Your question should be how long will a FORTY pound or larger tank run. ;) I asked the guys at the welding supply company where I buy my gas if I could run an Oxy-Acetelyne tourh with propane for operations like heating and switching damascus bars using a rosebud tip? The first thing that they asked me was how big is your propane tank. I said 100 pound and they said yes, I could.
 
Yea, we use a forty but it seems a lot of guys use 20 pounders..You can get the tank mostly empty before it freezes up if you put it in water(you probably already know that though)..Im just asking like that because it seems like most of the guys I see are using 20 pounders to run their forge with.
 
I run a twenty but thats because its what I had to start with. I haven't run it enough to run out the 2nd tank I just put on it. But I've put in about 6 hours on the forge and I'd guess its more than 1/2 full based on the weight.
 
My (2) tank manifold(20lb each) will run the forge for 35-40 hrs @ 3.5 to 5 PSI. Here are some tips that help me increase the efficiency...

- Use enough insulation. 2" minimum
- Use ITC coating (worth the extra money). It helps reflect the heat back.
- Use a 2 tank manifold. No more ice ups.
- Make an idle loop and USE IT. Mine turns down to 2lbs at the flip of a switch.
 
Greetings,
You get 35 to 40 hours on 40 pounds of propane at forge welding temperature? Please post picture of you forge, as mine does not get close to that performance.

Regards,

Dennis Paish
 
Not forge welding temperature. If I want to forge weld, I bump it up to 7-9 PSI or higher for large pattern welded billets... but I rarely make damascus. 3-5 PSI will last me 35-40hrs if I am diligent about using the idle circuit. I sometimes don't have to fill my tanks for a month or two. My small forge is a 6x10(3x10 cavity) and it'll last 20+ hrs on one 20lb tank. My main forge is made from an old propane tank. 4 x 4 x 12 cavity, 3inches of kaowool with ITC. The burner is a slightly modified Zoeller Z-burner.

Imagine if you were able to cut your PSI down by HALF whenever the piece is out of the forge. Thats what an idle circuit does for you. That said, I recently reconfigured my forge and don't have the idle set up... I have been on the same two tanks since August.
 
Last edited:
Here is a picture that Larry has on his site. Mine is very similar. You set the needle valve to the lowest operating pressure you can(do this while the forge is at full heat). When you flip the ball valve, the system drops into idle mode. Your forge temperature will not drop while in idle mode... until you put a cold bar back in.

idle.jpg
 
You must log in or register to reply here.
Back
Top