larrynjr Posted July 15, 2008 Share Posted July 15, 2008 I ordered a new adjustable regulator for my gas forge and it really makes a huge difference in the heat of the fire. It is a 0-20lb. gauge and I have it down between .5 and 1lb of pressure. Anything higher than that and the dragons breath gets so big that I would not be able to forge at all! I was able to get a white hot heat in the middle of the forge and got my first weld ever. It was not a completely solid weld, I folded the piece over and tried to get it to weld but was only successful in at the bend, then I folded it again and got a little more weld but as you can see in the picture there are some area's with scale that didn't weld. I'm still happy with the progress though. One question regarding the change in regulators, obviously the pressue is about as low as I can get it but the force into the forge and the overall volumne seem to be much higher than what I got from the old regulator. Can anyone explain how that works in small easy to understand words? Also will I use more or less gas than before? If the volumne is indeed higher than I'm guessing more gas will be used. Quote Link to comment Share on other sites More sharing options...
Valentin Posted July 15, 2008 Share Posted July 15, 2008 Hmm i never got that far ! Congrats on the forge weld ! Quote Link to comment Share on other sites More sharing options...
Sabre Posted July 15, 2008 Share Posted July 15, 2008 well good job!!!!!!!! Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 15, 2008 Share Posted July 15, 2008 What were you using as a flux? How oxidizing is your forge? Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 15, 2008 Author Share Posted July 15, 2008 it's a welding / brazing flux I got from the local Oxarc store. I've been meaning to try some 20 mule team borax but have not yet. With the new regulator I have to have my air door fan all the way open or again I get lots of dragonsbreath. Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted July 16, 2008 Share Posted July 16, 2008 I would guess the old regulator had a smaller hole on the output side, resulting in less volume of propane to the forge. It's not just pressure, volume is significant also. I use a 0-60 lb regulator, cranked all the way up and control volume with an Alcon needle valve. I have not had problems getting enough heat for forge welding since I moved to this setup.... Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 16, 2008 Share Posted July 16, 2008 The old reg is in inches of water, not lbs. Unless I'm misidentifying the thing. It looks like the kind you see on Coleman propane stoves. They deliver too low a volume and too low a pressure to work well in a forge if at all. At least that's what I think I'm looking at. I could be wrong. Frosty Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 16, 2008 Author Share Posted July 16, 2008 I looked at the old one before taking the picture but didn't see any marks that ID'd it one way or the other. It's been so long since I got that one, I forget exactly where I did get it, so it's quite possible it was from a coleman stove. I know it was hard to get a consistant flame in it and after an hour or so, when the tank got colder the volumne would decrease significantly. The new one I ran for at least a hour with no sign of decreased volumne. I guess I'll just have to run it and see how slow or quickly I go through this tank. Good thing I filled it recently! Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 16, 2008 Share Posted July 16, 2008 I'm just going by the general looks of it. I could be completely wrong but it's performance reinforces my opinion. Actually what the old one is doesn't matter, the new one is working properly. Yes? Frosty Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 16, 2008 Author Share Posted July 16, 2008 I would have to say, YES!!! it is working properly. A very high heat output that makes forging easier. Though there is a higher amount of scale due to the increase in air flow. I just need to remember that not everything needs to be welding heat hot before I hammer it! Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 16, 2008 Share Posted July 16, 2008 Is it scaling in the forge or after you pull it out? If it's after you pull it out, that's just the way it is unless your flux to prevent it. If it's scaling in the forge it's burning lean and you can richen it up to eliminate the problem. Frosty Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 16, 2008 Author Share Posted July 16, 2008 I would say it's scaling in the forge, it doesn't matter if I'm using flux or not. As soon as I take it from the fire and hammer on it, large chunks of scale start flying off. When you say richer, I'm guessing you mean more gas less air. I'll have to play with it to see if I can get the right combo of air to gas to still get welding heat but without the dragonsbreath 2 feet out of the forge. Quote Link to comment Share on other sites More sharing options...
Chuck Richards Posted July 17, 2008 Share Posted July 17, 2008 What is the opening on your gas line into your forge?? If you are looking for a little more control try making the opening smaller. I used to pinch the end of some 1/4 inch copper pipe and drill a hole in it to the size I want. I used to use a #54 drill. You may need to play with it to get optimum performance. I have since gone to a design based on Kevin Cashin's forge set up On his web site. It uses a needle valve to control the amount of gas allowed into the forge and a gate valve to control the air flow. Much better efficiency that the old forge and easy to control at lower temps. Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted July 17, 2008 Share Posted July 17, 2008 Larrynjr... You mentioned a few posts ago .........I know it was hard to get a consistant flame in it and after an hour or so, when the tank got colder the volume would decrease significantly. The new one I ran for at least a hour with no sign of decreased volume. When your tank gets low, and you are using a fair amount of gas, it is normal for the tank to frost up and give you decreased propane flow (lower pressure in the tank). When you have a full tank, this doesn't happen, so your experience with a near-empty tank, then a full tank, is normal. Make your judgements on your equipment with a full tank only. I have lessened the effect from a frosty tank in the past by putting the propane tank in my slack tub (now I have ganged two small tanks together to avoid the problem). If you do put the tank in your slack tub (or some other tub), be sure it stays upright. You DO NOT WANT the tank to tip and deliver liquid propane to your forge. It would not be pretty. Quote Link to comment Share on other sites More sharing options...
Chuck Richards Posted July 17, 2008 Share Posted July 17, 2008 DJ A larger tank will help. I use 100lb tanks. They hold 20 gals of propane and eliminates freeze up. One tank will last for 3 days of forge welding. Thats about 6 hrs a day so 18 yours. That is a little over 1 gal/hour. my forge is 8" id and 18" long with 4" of cerachem wool and a layer of castable. Freezing is common if you are drawing gas too fast so the old slack tub trick works well also. Like you said just keep it from tipping. Wayne Goddard goes even further and puts a heater into his slack tub. Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 17, 2008 Author Share Posted July 17, 2008 The opening for the gas is fairly large; 1/4" maybe? The overall design is based on the hand drawn plans given out by Jerry Culberson at his course at Old Cedar Forge. I guess I need to start playing with that end if I want to achieve more control over the fire. I forged tonight for almost 3 hours. I did increase the gas pressure a bit and decrease the air flow which lowered the overall temp a bit but I'll figure out something for the gas pipe to reduce the output hole. I have a 25gal. propane tank that I use and with the old regulator it would still start to frost up as it got empty. With the old regulator the flow would decrease after an hour or so even with a full tank. Depending on how much or little the volumne decreases as the tank gets empty using the new regulator I may spring for a second 25gal. tank and use them in tandem. Quote Link to comment Share on other sites More sharing options...
Chuck Richards Posted July 17, 2008 Share Posted July 17, 2008 Larry How fast are you going thru propane?? If you smash the end of your copper tubing and then drill with the #54 drill it will help a lot. If your blower is going full blast it is probably too much air. Make a gate for the input and damp it back. You r pressure may go up on your guage but pressure and flow are connected. Smaller hole higher pressure for same flow. My forge I had the air gate on the input almost completely closed and still had plenty of air for the fire. Also the forge should be really quiet. If it sounds like a jet engine it is not efficient. Let me know if I can be f firther assistance. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 17, 2008 Share Posted July 17, 2008 (edited) Sounds like your old regulator was icing up and lowering delivery. This shouldn't be a problem with the new reg. but if it is make the orifice smaller. With a 1/4" orifice there is a significant pressure drop across the regulator which can cause icing. A smaller orifice will keep the differential smaller so there is less chance of icing. And yes, either increase the gas a little or decrease the air a little. When you have a neutral flame it will be hotter. What you describe though is scaling outside the forge which is a natural outcome of bringing hot steel into the open air. A layer of borax will stop the scaling till you've beaten it off the piece. You'll still end up with less scaling and more holes burned in your clothes and hide from molten borax splatter. Molten borax splatter . . . Mmmmmmm. Frosty Edited July 17, 2008 by Frosty Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 18, 2008 Author Share Posted July 18, 2008 So I went to the hardware store and picked up a new piece of copper pipe with an end cap to replace my existing steel pipe with no cap. BUT I got ahead of myself and drilled the hole for the gas without checking for proper placement and made the hole in the middle of the pipe and it needs to be closer to the cap to actually be inside the gas / air intake pipe of the forge. I've taken pictures so you can see what I've been using and how large the original pipe oriface is / was compared to what the new one will be. Would it be safe to solder the small hole that's in the wrong place closed and drill a new hole closer to the cap it would there be too much pressure that might blow the solder out and cause explosion issues? Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 18, 2008 Share Posted July 18, 2008 No problem Larry, there's no way it'll build enough pressure to blow a solder plug out of so small a hole. Heck, it'd probably take full tank pressure. NOT that I'm saying you should give it a try! Frosty Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 18, 2008 Author Share Posted July 18, 2008 Thanks Frosty, I'll give it a try and let you all know how it goes! Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 18, 2008 Share Posted July 18, 2008 Thanks Frosty, I'll give it a try and let you all know how it goes! My pleasure Larry. Another solution if you think solder won't hold is to tap the hole and install a set screw with some high temp locktight to seal it. I still don't think solder's a problem in this application but just thought of putting a screw plug in the hole and thought it worth a mention. Frosty Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted July 18, 2008 Share Posted July 18, 2008 When I built a forge I had to try several jet sizes to get it right. When I went too far and drilled too large a hole I would solder the hole shut and redrill it smaller,, worked fine. however after useing the forge for long periods then turning it off the solder would melt out. When the forge is running and gas is flowing it worked I think the gas kept the solder cool enough to stay intact. I believe you could braze that and it would work. Or plug like suggested above. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 18, 2008 Share Posted July 18, 2008 A good thing to do whenever building a gun burner is run the mixing tube around a 90* bend after introducing the gas. This does several things: First, it really aids in mixing the air and gas. Propane and air do not mix well without some extra turbulence. Second, it reduces (not eliminates) the chances of a backfire. Flame fronts don't like going around corners, they will but they don't like it. Third, it lets you put the blower and gas jet where convection won't heat it up when you shut it down. Fourth, It allows a more compact design by letting you put the blower in the stand under the forge furnace. No problem running it around more than one bend as long as you don't get too carried away. Each bend will require more pressure from the blower to overcome the backpressure but one or two won't effect it much. Frosty Quote Link to comment Share on other sites More sharing options...
larrynjr Posted July 21, 2008 Author Share Posted July 21, 2008 So here is what I ended up doing with that piece of pipe. I tried soldering it but wasn't satisfied with the results so decided to give this a go instead. I drilled the air pipe all the way through then passed the jet pipe all the way through so that the original hole is centered (more or less) and the pipe itself acts as a gas / air mixer. So the net effect is that I'm running at a higher pressure, about 10lbs. and should be lower volumne but I have no way to acurately guage that. The flame torch as it burns inside the forge is blue and the forge is a bright orange heat with little dragonsbreath unless I close the air intake on the fan all the way. The air intake is closed 4/5th of the way. I didn't have time to try it last night but I'm guessing to get that white hot welding heat again, I would need to either increase the pressure to increase the volumne of gas or to enlarge the jet hole to get more volumne. Overall I'm pleased with the current results, as I'm getting a more consistent fire. Quote Link to comment Share on other sites More sharing options...
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