RainsFire Posted October 9, 2007 Share Posted October 9, 2007 My father and I are finishing up a project that has taken us for ever to complete, being a gas forge.. We took a 12in diamater tube and lined it with kaol wool, and refractory cement.. so it was done right.. Then we got a venturi blower from a friend of ours who is a brilliant inventor, but seems to have skimped on his blower designs.. We are running it without a regulator, which may be part of the problem.. but when we do use the reg, not nearly enough pressure is built up to acchieve the venturi effect.. And when we do get it going, the flame spurts, and is not constant.. I can only hit about an oarnge red heat, which sucks.. so basically, why cant I get above red/orange heat? and why wont my flame stay constant? IT might be the burner, but it is simple and should work fine.. there's no real choke design, but there is a choke in the pipe going to the fire box, (torch tip) which seems to adjust heat, but not really oxy content.. please help me out, thankyou.. Quote Link to comment Share on other sites More sharing options...
Dodge Posted October 9, 2007 Share Posted October 9, 2007 You MUST have a regulator. 0 - 30 psi. Is your gas line too small? Your jet diameter may be too small, or you may not be getting enough air or you may be getting too much. Many, many factors involved it venturi effect. BTW, not familiar with venturi blowers. Usually categorized as blown burners (burners that use a blower, and are usually easiest to make work correctly) or venturi or naturally aspirated burners (those that don't use a blower). Please look at this site: Forge and Burner Design Page #1 alsoRon's Forge Page He was a physics instructor and has done his homework (no pun intended). Especially, absorb his safety precautions! Seriously look at the "Reil" and "EZ Burner" designs. These are the most copied burners in use today. I use a variation of them and I can get weld heat. P.S. in case I forgot to mention it, please read and heed his safety precautions!! :) Quote Link to comment Share on other sites More sharing options...
Mithral Posted October 9, 2007 Share Posted October 9, 2007 I use a variation on Reil's design that a friend came up with, and it works quite nicely for us. Unfortunately we can't seem to find reducing bells with the right shape anymore, but melting metal in a home foundry, backyard metalcasting, metal casting has a propane burner design that is naturally aspirated without a reducing bell. It's just a length of pipe with some holes for air intakes, and it looks an awful lot like a crude version of my blowtorch. I'm still waiting till I have the time and the inclination to try it out (I hate drilling in pipe without a drill press, it bugs the bajeebers out of me.) Our jet was drilled with a #60 bit, but I've heard of people who don't like those little fiddly drill bits drilling a bigger hole and tapping it so they could put in welding tips (never tried it myself.) Definitely use a regulator, preferrably with an emergency on/off valve. We've got a cheapo red regulator with a gauge on our burner, our hose is the standard stuff you can buy at the hardware store as replacement propane hose for BBQ grills. Quote Link to comment Share on other sites More sharing options...
KevinD Posted October 9, 2007 Share Posted October 9, 2007 I am also trying to build a burner. I have been buying parts from Home Depot and Ace Hardware and have not yet been able to find all the parts needed in one place. I'm sure I need to find a "real" plumbing supply store to get the required parts. I got so frustrated that I ordered a Side Arm burner kit and a single burner connection kit from Zoeller Forge. The invoice was $115 for both to my door. Burner Flares & Gas Forge Parts I can't wait till it gets here... Quote Link to comment Share on other sites More sharing options...
Pault17 Posted October 9, 2007 Share Posted October 9, 2007 KevinD and all, I have mentioned, in the past, that I went with a rex price shorty (Welcome to Hybridburners.com) burner. Looking at his price list, it is the least expensive of his line ($118 for a complete burner). I have been using mine since just after christmas with absolutely no problems. I could have built one but had to make the decision of "build burner or bang iron". Eventually I may build my own or just go with a coal/charcoal forge. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 9, 2007 Share Posted October 9, 2007 The big question is what regulator are you using? One from a typical gas grill will not go to high enough pressure for an aspirated forge. You need a "high pressure" propane regulator. "Redhat" is a common industry brand. Second is to make sure there is no crud in the system that can clog the hole, teflon tape scraps are famous for this. Final is alignment, particularly with improvised bells the hole needs to shoot straight down the middle of the pipe. Some folks hook it up to water for testing and adjustment, (only the burner NOT the regulator!!!) as the water stream can be seen and centered. Thomas Quote Link to comment Share on other sites More sharing options...
Jmercier Posted October 9, 2007 Share Posted October 9, 2007 Venturi burners also work differnetly based on the forge they're put in. Different forges produce different back pressures and air currents. In general when making your own forge it tends to be much easier to make a blown propane forge and not a venturi one. You can tune a blown propane forge much easier, and there's a lot more leeway for error. Quote Link to comment Share on other sites More sharing options...
RainsFire Posted October 10, 2007 Author Share Posted October 10, 2007 so, I think it may have actually been my tank if thats possible.. because today when I got home I fired it up to temper a blade I made, (gets hot enough for that atleast..) and after it had a small blow back issue.. which isnt a big deal It sort of warmed up and started growling.. Lots of heat, not quite welding temp, but definatly yellow.. so im pretty happy. It might have just been teflon tape.. and the blowback melted it or something.. Thankyou for your help yall. Quote Link to comment Share on other sites More sharing options...
KevinD Posted October 10, 2007 Share Posted October 10, 2007 Pault17 said: KevinD and all, I have mentioned, in the past, that I went with a rex price shorty (Welcome to Hybridburners.com) burner. Looking at his price list, it is the least expensive of his line ($118 for a complete burner). I'm with you on the Rex Price burners but I'm on a budget and for the same price as the shorty I got the burner and connection kit from Zoeller. Also I'm currently in the "learning" mode and have learned a lot about these burners from trial and error...and a lot of reading. I'm as excited about "tuning" this side arm burner as I am looking forward to actually using it to heat metal. ThomasPowers said: The big question is what regulator are you using? One from a typical gas grill will not go to high enough pressure for an aspirated forge. Another plus for the Zoeller kits. I don't have to piece together the burner OR the plumbing...but I DO have to put it all together which adds to the learning aspect and the comprehension of how it all works. I got some Kaowool off ebay and some ITC100 from on line. Now to find a suitable forge body and put it all together... RainsFire said: today when I got home I fired it up to temper a blade I made, (gets hot enough for that atleast..) and after it had a small blow back issue.. which isnt a big deal It sort of warmed up and started growling.. Lots of heat Good for you! Quote Link to comment Share on other sites More sharing options...
Mithral Posted October 10, 2007 Share Posted October 10, 2007 By the way, quick tip for anyone in need of a forge body for a gas forge. Head on down to your local flea market or military surplus store and try to find an ammo can for 5.56mm rounds, the cans marked 800 rounds are perfect. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 10, 2007 Share Posted October 10, 2007 My propane forges are "pipe" forges; one 10" grain auger pipe the other a tad smaller and was the body of an O2 welding cylinder. The auger pipe forge is light and portable, the O2 cylinder is heavy stable and you can weld on lots of bells and whistles. Kaowool will hold an arch form in a pipe forge naturally, no clips of supports needed. Quote Link to comment Share on other sites More sharing options...
Mithral Posted October 11, 2007 Share Posted October 11, 2007 I'll never know if the kaowool would have held it's arch in the ammo box forge, because I coated down the inside of that sucker with fireclay and ITC 100 on top of that. Quote Link to comment Share on other sites More sharing options...
Ian Posted October 11, 2007 Share Posted October 11, 2007 I bought a flare from Larry a long time ago for my furnace and I also got his version of ITC100 at the same time. Don't know if he still sells it but I remember it being a heck of a lot cheaper than Jock at Anvilfire's ITC100 Quote Link to comment Share on other sites More sharing options...
sdalcher Posted October 12, 2007 Share Posted October 12, 2007 Your problem may have been the overfill prevention device (OPD) on your tank. If the tank is filled full+ sometimes the OPD can get jimmied in an awkward place and will limit the amount of gas delivered. The cure is to run at very low pressure for a short period of time to allow the OPD to essentially reset itself. Steve Quote Link to comment Share on other sites More sharing options...
RainsFire Posted October 12, 2007 Author Share Posted October 12, 2007 ^^that could have definatly been it, because after we tried out the crummy bbq reg, which ran at a super low pressure it began to work. Thanks again for all your help! Quote Link to comment Share on other sites More sharing options...
Pault17 Posted October 13, 2007 Share Posted October 13, 2007 Another good idea for a gasser body is an old 7 or 10 air tank, new for about $25-35. cut the frotn off and hinge it. cut a port in the back, bolt or weld on legs/supports, line the bottom with a layer or two fo fire brick and fill the rest with a double layer of kaowool. You could also just kaowool the whole thing and do that neat poured refractory floor thing. I like to coat the wool with several layers of satanite or like material, then coat every thing with a nice layer of itc100. To dry out/bake the inside I did the expedient of putting a bare 100-watt light in the cavity for a day or so. It was really amazing how hot it got in there and how little heat got out.:) Quote Link to comment Share on other sites More sharing options...
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