Bram Posted June 26, 2005 Share Posted June 26, 2005 Helo, I am new in the blacksmithing business and just now building my gas forge and need some advice: I use a standard home gas tank & regulator and fan for forced air but do not get enough heat. The 1/2" bar I am trying to work with stays black. Some facts: - Color of flame is blue. - The forge chamber is not isolated (working on it...) - Gas orifice is 1/16" - I tried all variations of air and gas flow with no success. Can anybody help? Quote Link to comment Share on other sites More sharing options...
Ralph Posted June 26, 2005 Share Posted June 26, 2005 standard regulator? as in for a BBQ? If so that is your probelm. Will not allow enought pressure. Go to the propane place and ask for a high press regulator. Around here they call them red hat ( no clue as to why). 8) Quote Link to comment Share on other sites More sharing options...
Bram Posted June 27, 2005 Author Share Posted June 27, 2005 Yes, same as for BBQ. Can you tell what should be the pressure? Quote Link to comment Share on other sites More sharing options...
Ralph Posted June 27, 2005 Share Posted June 27, 2005 If you ask the local propane place they have to correct one. The one you have might go as high as 10 lbs not high enough. Do any of yall know the pressure ranges? I was thinking 0-60 but I am just guessing here. Quote Link to comment Share on other sites More sharing options...
Shane Stegmeier Posted June 27, 2005 Share Posted June 27, 2005 0-30 PSI is prefered... Most gas forges run on 7-15 PSI, so really efficient ones can run on a LOT less, and some big ones with bigger tanks can run on 20-30 (Think cuopola with a couple of 1.25" T Rex burners:-) I believe that Red Hat is the brand name, that is most common, they are normally painted, you guessed it Red:-) Around here, west central Indiana TSC farm stores carry them as well as 100# propane cyclinders, and high temp stove cement. To get the most proformance out of your forge you need combination of types of REFRACTORY, hard resistant refactory, and soft insulative refactory. Silicon Carbide Kiln shelf is a popular hard refactory, and reasonably easy to aquire material, it resists most fluxs well and absorbs some heat, and is pretty durable. Hard high temp fire brick also works, as well as a hard investment type refactory. The kiln shelf absorbing heat can be a good thing if the forge is designed properly, with a fire box in the middle of the forge out of the kiln shelf the hot box helps with combustion, and speeds reheat time. It does not make a good material to build your entire forge out of since you will radiate heat through the kiln shelf... Kaowool and Inswool are available as insulative ceramic? fiber blankets and also as boards that reflects heat pretty well, they are however not very durable, but they can isolate the heat inside the forge where it will do the most good:-) They should be coated with ITC100, or a diluted slurry of high temp stove cement to protect the friable fibers of the bats of wool from degrading and putting dangerous fibers into the air you are breathing.... The soft superlight weight fire brick is also quite useful... Having a durable firebox where your work can rest, and absorb heat from the floor of the forge as well as the burning gas, is good... Being able to get close to the forge, because you and your surrounding work space are insulated from the radiant heat is also good. You can do little about the excess heat bled off of your forge in the dragons breath exhaust, unless you build a recuperative forge. All forges have a certain amount of venting that they must have to work efficiently, and your work space must have a certain amount of venting so you have sufficient FRESH air to continue to function (ie live:-) If your burner design is not right and it is not tuned correctly you could be pumping deadly carbon monoxide, and dioxide into your workspace, it had better be WELL vented and supplied with fresh air. Bottom line is the best advice is to Go to Ron Reils website, and read everything written there, and get Neil Porters book on "Burner and Forge Design", and it probably wouldn't hurt to cough up and buy a couple of T Rex burners from Hybridburners.com, and some Kaowool & ITC100 from the Anvilfire store. It is one thing to play with hot metal if you don't quite know what you are doing, it is quite another to play with flamable gases:-) It is hard to explain everything you need to know, and even if I did I would be replicating a much of the material on Ron's site and in Neil's book (and I wouldn't do as good a job, especially at this time of night;-) Building a really good homebuilt gas forge is relatively easy... WITH THE RIGHT INFORMATION:-) DO a little more indepth research, and understand how and why a gas forge works, then build one. I don't want to offend, but there is a little too much information you need, and it really works better to understand how a forge opperates, so you know why you need to design your forge a certain way. Hope this helps:-)edit: URL's added Quote Link to comment Share on other sites More sharing options...
Bram Posted June 27, 2005 Author Share Posted June 27, 2005 Thank you for the information. A lot of homework to read... Quote Link to comment Share on other sites More sharing options...
Ralph Posted June 27, 2005 Share Posted June 27, 2005 Bram, when I built my first gasser 12 years back, I read Ron's page. Thought about it got confused, and so emailed him. He and I emailed for quite a while. But the end result was for a me a good first attempt. Just as a warning Ron is much less likely to talk with folks today. But if you really read his stuff and all and you still have questions it will not hurt to ask him. He believes that you need to have a certain 'native' inteligence to do this so often times cuts people off. Since then I have been to Ron's ond place once or twice. And look forward to visitiing his new place. Also feel more than free to ask us here. Quote Link to comment Share on other sites More sharing options...
Bram Posted June 27, 2005 Author Share Posted June 27, 2005 Thank's for the advice. Just talked to my gas supplier. I want to hook up to my bulk tank (much cheaper comparing to 40 kg cylinder) but need him to do that due to our local safety laws. He will install the needed regulator with gauge at cost charge only. Quote Link to comment Share on other sites More sharing options...
Marc Posted June 27, 2005 Share Posted June 27, 2005 Just a little filler information, because it sounds like you're well on your way - The "red hat" is probably because of its shape and color. Fisher makes them, and they come in all sizes. The 0 - 30 is what works with the Reil, T-Rex, etc. burners. BBQ regulators usually only deliver 11" of water column (wc), which works out to about 0.3-0.4 PSI (if I remember correctly). You can design a burner to work on that little pressure, but it needs a blower. However, the BBQ regulators can't deliver the BTUs/hr you need for a forge. Over in my neck of the woods, New Hampshire, no supplier will deliver any more than 5 lbs of pressure to a residence. That's in the National Fire Protection Code. There were a few who wouldn't deliver more than 11" wc just to be safe. But having a bulk tank is sooooo convenient that I went with a blown burner. No more freeze-ups, no more running out on Sunday afternoon, no tanks stored in the shop, ... And now my grill has gas once again :D Quote Link to comment Share on other sites More sharing options...
the other dave Posted June 27, 2005 Share Posted June 27, 2005 I'm confused. If you are using a blown burner, (fan-forced air), then I think you should try the North Texas Blacksmith Site, http://home.flash.net/~dwwilson/forge/forgeplans.html. On the other hand, if you want to use an atmospheric burner, (venturi), then Ron Reils web site is great. Remember that if you use a blown burner system that the gas pressure is not important and rather the amount of gas you can get to the burner becomes the limiting factor, whereas, in the atmosmpheric burner you are relying on the pressure of the gas to move the air into and through the burner. Quote Link to comment Share on other sites More sharing options...
Bram Posted June 28, 2005 Author Share Posted June 28, 2005 Yes, I am making a forced air burner and what counts is amount of gas flowing into the forge. Now I am thinking that I might play with the orifice size... but first going to have a look at the site you quoted. Quote Link to comment Share on other sites More sharing options...
Marc Posted June 28, 2005 Share Posted June 28, 2005 A blown burner changes things. You might want to consider having a low pressure regulator run to the shop. With a blower, you can get by with any pressure, but you need to specify that you'll be wanting 100,000 BTU/hr delivery. You probably won't use that much normally, but it's nice to have it available if you do. However, the lower pressure you get, the bigger the piping to the forge you'll need. With a lot of gas going through, there will be some pressure drop through the system. I don't know the specifics off-hand, but there are tables on the 'net that tell you how much, depending on pipe size and length. If you've got 30psi, then a few pounds of drop don't make much difference. But at 11"wc, the system could be limiting. I've got 5psi coming into the shop and that goes through about 16ft of 1/2" copper tubing. I get plenty of heat when needed with this. If I were to go with lower pressure, I would probably need at least 3/4" pipe. 1" would be better and doesn't cost much more. The reason for low pressure is safety. At 30psi a broken pipe/tube/hose can pour a whole bunch of propane into a shop in a short time, a whole lot more than 100,000 BTU/hr. With low pressure, the system will limit that amount. And low pressure is easier to contain. Systems that show no leakage at all at 5psi could leak at 30. Blown burners are much more forgiving to build, because they take out that air intake question. And I'm told that Doug Wilson's "flame holder" really quiets things down. I'm going to experiment with that concept more on my forge. Quiet is good. But you can't do that with an aspirated burner because they're real sensitive to any obstruction in the flow. However, natural aspiration makes the forge more portable. Good luck. Stay safe. Check all piping for leaks (soapy water works well). Quote Link to comment Share on other sites More sharing options...
Bram Posted June 28, 2005 Author Share Posted June 28, 2005 Thank's Marc. So I am back with the question, maybe my problem is too small orifice? (I am using 1/16" hole). If I'll try the current BBQ regulator with higher flow (bigger orifice), will I have more heat? (I have big enough fan) Safety: My shop is outdoor. ie, I have only roof and 2 walls so there is less risk of CO ect. Quote Link to comment Share on other sites More sharing options...
Marc Posted June 28, 2005 Share Posted June 28, 2005 The orifice might be a problem. At 11"wc, I think you need to go to 1/8". But the BBQ regulator, if it's from a standard grill, probably won't allow a lot of gas to pass through it. They'll handle what the grill is spec'ed for, 35,000BTU, 50,000BTU? That might be enough to get steel hot, though, but maybe not to welding heat. At this point, a lot depends on the forge contruction itself. You can get to welding heat in one of those coffee-can forges with a little propane torch. So it's all relative. Ron Reil's site does have some guidelines on forge sizes and BTU requirements, so you can start there to find your burner needs. Then, if the BBQ regulator fits, play with the orifice. Quote Link to comment Share on other sites More sharing options...
Marc Posted June 28, 2005 Share Posted June 28, 2005 I just re-read your initial post. You said the chamber was not isolated. Do you mean insulated? If not insulated, then you're no better off than forging in a gas grill. All your heat is just escaping. You really, really, need to insulate. Propane doesn't have the heat content as coal and the flame needs to be contained. Finn's previous post covered that very nicely. Quote Link to comment Share on other sites More sharing options...
T-Gold Posted June 28, 2005 Share Posted June 28, 2005 Trying to quiet down a forge? Blown burners? I can't imagine smithing without the happy purr of my gasser :) Quote Link to comment Share on other sites More sharing options...
Bram Posted June 28, 2005 Author Share Posted June 28, 2005 Yes, I meant insolated. Just now chamber is build from roof tiles held by metal welded frame. New construction will be based on light bricks. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted June 28, 2005 Share Posted June 28, 2005 I run on 4 lbs of pressure thru a standard acetylene regulator with no orifice. I dump the gas thru a 3/8 line and meter with a needle valve before it goes into the airstream. I also have a completely enclosed box with a door on the front so the interior can heat up properly. I use a 60 cfm squirrel cage from WW Grainger. This was an old Sandia style, naturally aspirated forge but was subject to performance fluctuations depending on the weather so I added the blower and changed the burners. Although it is still not as hot as the coal forge, it will forge weld with no problem. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.