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After finally getting my shop in order to start forging at home, I realized that as I was working the propane pressure was steadily dropping. Whenever I would try to turn the pressure back up, it wouldn't change anything. I had been checking it for leaks a few days prior and it all checked out fine. Any ideas on what I should do?

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The regulator is 0-30 psi. I ran it again a minute ago after checking all the connections and the pressure started around 12 and when I looked again after a few minutes it fell to 3 before the front burner started puffing out fire in increments instead of a steady stream. I don't know how to check how full the tank is, but I highly doubt that it's out since I bought it full and have only used it for maybe a little over an hour collectively.

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And for the record, I once got a supposedly full bottle from one of those grill gas exchange places that turned out to be empty. Always have you bottle filled, don't exchange. You get three more pounds that way too.

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What forge are you using that you need to run it at 12 pounds? That seems awfully high, and would use up propane pretty fast. I run the NC Tools whisper daddy (3-burner) at 4 or 5 pounds and my ribbon burner (with blower) at 3 pounds.

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I haven't able to do any real work due to third hip surgery a few months ago, needless to say the forge sat idle. I've kept my regulator at a setting which I know works best, cutting the tank off first, then closing the 1/4 turn ball valve until next firing. Had it like this for 3-4 years. That's not recommended and I won't do it again. Several days ago I simply wanted to fire it up, I had no control over the regulator, sounded like a train coming through almost blew me off these crutches. I shut it down and ordered a new adjustable on line. Had the same problem you describe. So I check for spiderwebs,( which are water resistant but not acetone) , none found. Got out the soap/water and checked the joints.....guess what. After re-taping and retightening two joints on flex hoses ..... no issues. I don't have a great sense of smell these days but I thought at times I caught a whiff of propane.

So, therein lies a couple of possibilities and a warning as well.

Gary LT(

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The forge I use isn't commercial, it's one I made myself. I checked all the lines repeatedly with soap and water, but I guess it wouldn't hurt to check again. I run it on the higher end because I'm used to forging at high temps, having used a professional grade coal forge for three years before making my gas one, and lower pressures don't seem to get me there. I think it might be the tank, but this would mean that the tank exchange place gave me a nearly empty tank which it's weight upon purchase would not have suggested.

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I have a home made propane forge, not a blown one and it runs at pressures around 10-12lb to get good heat. I have heard several times from other smiths about how a blown forge will only need in that 3-4 lb range. That said, I can get a full day+ of forging out a 20lb tank, just my 2-cents.

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If you have a scale weigh your tank. That will tell you right off. Also, Alan is right. Getting tank filled a way cheaper and a more complete fill than trading it in. A full #20 bottle should weigh about #40. If your close to 20 that's likely your problem.

 

If you don't mind could you post a pic of your forge? Just curious. I'm building one and like to see what people have done.

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I redused my propane useage a LOT by adding an air blower. I used way too much propane to reach the temperatures I wanted with the "venturi" i had. With the forced

air, its allmost a problem keeping the temp down. And thats with a lot less propane running through.

 

Lars

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I redused my propane useage a LOT by adding an air blower. I used way too much propane to reach the temperatures I wanted with the "venturi" i had. With the forced

air, its allmost a problem keeping the temp down. And thats with a lot less propane running through.

 

Lars

Same here. When I went to a blower assisted burner, I was getting much hotter with a lot less propane. My typical running pressure was at about 5-7 pounds, 5 for regular forging, 7 for welding heat. The ribbon burner with blower I use now gets to welding heat from dead cold in 7 minutes.

Here is the old blower assisted burner.

First Heat.jpg

 

The new ribbon burner running. (not a great pic)

Forge Running-opt.jpg

 

So I turned it off and took another pic.

Forge off-opt.jpg

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  • 1 month later...

So after a lot of screwing around, I sealed all leaks and Teflon taped everything that can possibly be Teflon taped. I picked up a full tank of gas and ran the forge today. The problem of the pressure slowly dropping on its own is persisting, however the pressure is dropping significantly slower than before. Does this narrow down the problem to anything you guys can think of?

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It sounds like you are just low on propane. Running at that high a pressure is going to run the tank low pretty quickly. I have noticed that when I set my forge (any of them over the years) at a specific pressure, the pressure does drop after a few minutes of running. It has something to do with the heat generated over time and back pressure from the burner. This is typical of almost every propane forge I have seen in operation. There is always a slight drop in pressure after running it for a few minutes. Another thing to realize is that the primary purpose of Teflon tape is not to seal thread leaks, it is to make the pipe fittings come apart easier if necessary. Pipe dope is the standard stuff used to seal the threads against leaks. Apply a healthy smear of pipe dope, wrap 4-5 layers of tape, and put it together again.

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I'm not dealing with a slight drop in pressure. It will drop all the way to zero to the point that I can hear the gas cut out and I only hear the sound of the oxygen noisily sucking in. Is there a way to minimize this and make it so it doesn't happen? I'd like to be able to forge for a few hours rather than a few minutes.

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Well, if you can hear something sucking in the gas has not cut out. A venturi burner is incapable of providing blast unless there is gas flowing. I suspect a regulator issue. Whatever it is, something is very much not right in the system.

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At some point you need to admit you don't know what you're doing. Take it to the local blacksmith group's next meeting and ask the folks there to take a look at it.

 

I now wholeheartedly agree with this statement. The symptoms you describe are not adding up to me. If the gas cuts out and the pressure drops to zero, what's making that "sucking" noise? Do you smell propane?

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I recently contacted the supplier that I got the regulator from and the said the problem was the fitting connecting the regulator to the tank. I ordered the fitting they said was right, this one having a bigger hole for propane to go into, and tried it out. That run had the pressure drop faster than any other before.

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