nick1018 Posted March 12, 2014 Share Posted March 12, 2014 Hey guys, name's Nick. I am quite new to gas forging, my only previous experience being with a really bad soup can forge. i was going to use coal but an very on the fence, due to the fact that i live in the city and and my coal supplier is very far out of town, because of this, i want an equally effective gas forge where i can hopefully even attempt forge welding. i have been looking around and decided on the reil burner design using a .75 inch burner tube. i have found a company that sells kaowool in the 2 inch thick range. because i have never built a gas forge, i am unsure about what dimensions i should use. i wish to get it up to welding heat and so i assume that the smaller the inside diameter, the more heat that burner will put out. i also am unsure wether i should put the burner on the top or side. I've been kicking around the idea of ether using a coffee can or a 20 lb. propane can. i don't want something super huge but need it big enough to work in and hopefully weld, nothing big but say large enough to make a pattern welded blade in the future. i know it is a lot to ask but i am just starting out and need someone to point me in the right direction. thanks Quote Link to comment Share on other sites More sharing options...
VaughnT Posted March 12, 2014 Share Posted March 12, 2014 There are probably a thousand forge build threads on IFI, explaining it all in incredible detail, including all the many variations and why. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 12, 2014 Share Posted March 12, 2014 OK this reads to me as "I've never drive a stick shift vehicle and would like you to help me choose one that is easy to learn on and economical to run" got that picture in your mind? "Once I've learned how to drive stick I want to use it to carry 16 tons of gravel." How did this changer your mind picture? Mine ran into a bridge abutment... Note that the size of the forge does not have anything to do with how much heat the burner puts out. (unless back pressure cause problem with the burner) The burner puts out the heat it was designed for and the size of the forge then deals with how it is distributed and lost. Most burners have a rating of how many cubic inches of forge they can heat. Thicker insulation or better types of insulation can allow a burner to do a bit more but that's through controlling heat losses rather than burner output. I am not a fan of top burners due to chimney effects when you shut them down *and* the greater tendency to re-run the exhaust through and so shoot up the CO production. So find out how many cubic inches of forge your burner is rated for and figure out a way to build that or a bit less. Don't expect this to be your only forge. If you stick with smithing you will probably end up with "minivan, sports car and dump truck" forges over time. I feel for your coal issues my coal supplier is about 5 hours away from where I live. Luckily I don't buy coal very often and I buy a year's supply at a time so the trip isn't too bad. Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 12, 2014 Share Posted March 12, 2014 Hiya Nick: A good place to start reading is the gas burner section. This will help in two major ways, first you may learn all you need and you can get on with building, smithing and shooting the breeze with the gang. Second it will at least give you enough information to ask good questions and understand the answers. Just so this isn't a total bust, don't use 2" ceramic blanket in a cylindrical forge. It doesn't roll smoothly and wrinkles mess up the flow of the flame so it heats unevenly. Two layers of 1" solves the wrinkle problem and makes repairing damage very much easier. Once you have a decent handle on things we'll talk kiln wash and why. By handle I mean have a better idea of what you want: scale, processes, room to work, etc. You actually seem to have a decent idea of what you're looking for, pattern welded knife billets puts a bit of scale on it but there's more. Hmmmmm, probably ought to start reading the knife sections too so you'll have an idea what it takes to make a Seax as opposed to a hook knife. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Bruno C. Posted March 13, 2014 Share Posted March 13, 2014 Nick, Save your money and buy a manufactured forge from an established manufacturer. I understand, if you are even here in these forums you enjoy making things with your own hands. Many of us are like minded. But for what you will ultimately spend building/fixing/tuning your own forge you can buy one for only a little bit more (if not less). As Mr. ThomasPowers has stated, you are likely to have more than one forge. I say get a good one to start forging and learn how it works and what to expect from a decent forge, then you will have some more information under your belt that will allow you to decide what you need to be more effective at what you are trying to do. To give an estimate, if you want to build something like a forge out of a propane tank, and do it properly, assuming you have the tools at hand, you can expect to spend at least $250 to $300 if you are careful. But then again, what is your time worth ? If you want to forge, buy a forge. If you want to delve into the dynamics of forge building, then do as others have suggested and do plenty of research on burner design, forge construction, maximum volumes for specified burner designs and all the safety requirements there in, as many of the materials (if not all) required to build a forge are hazardous to your health and those around you. I've built two of my own forges and found it rewarding, but I also spent lots of time researching, at least $300 on the forge/propane materials and (extras), and a bunch more money working with scrap and gas for trips to where I need to go. In the end, had I simply bought the right length of material in the first place (forge shell), I could have avoided a lot of work and saved some time and money after you calculate what I spent on cutting disks, paint, welding rod, grinding wheels, gas, electricity and any incidentals along the way, that $300 could probably buy me a really nice reliable forge that works out of the box. Building a forge is a very rewarding prospect if done right. I'm happy with what I came up with. But you'll get a whole lot more bang for your buck if you let someone that knows all about it do it for you instead. It's a lot of work. My .02 cents. -Bruno Quote Link to comment Share on other sites More sharing options...
nick1018 Posted March 13, 2014 Author Share Posted March 13, 2014 so from what i am understanding, it sounds like the most important thing i need to know to start designing is how many cubic inches one of these .75 inch reil burners will bring up to welding heat. once i have that figure, i can start designing the forge to fit that requirment. i am planning on lining with at least 2 inches of kaowool and using a few firebricks as a floor. ive scene that most are saying in the range of 300-400 cubic inches is about what these little guys will heat up that high. if someone could give me a closer range so i can start finding possable containers. thanks Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 13, 2014 Share Posted March 13, 2014 OK how many fingers am I holding up? Once you can tell me how many fingers I'm holding up I can tell you how good a job you did building the burner and if it should run at the upper or lower limits given. If you are intent of using it for welding shoot for a lower number rather than a higher one... There are a huge number of factors that come into play---like: are you at 7000' above sea leval or 7' above sea level? Btu content of the propane mix you are using? (it does vary you know) However if you want to weld be sure you line the kaowool with a flux resistant coating! Quote Link to comment Share on other sites More sharing options...
nick1018 Posted March 13, 2014 Author Share Posted March 13, 2014 i dont need it to be that spesific, all i need is a rough range to start in and then i can fine tune it from there. Quote Link to comment Share on other sites More sharing options...
Dodge Posted March 13, 2014 Share Posted March 13, 2014 so from what i am understanding, it sounds like the most important thing i need to know to start designing is how many cubic inches one of these .75 inch reil burners will bring up to welding heat. once i have that figure, i can start designing the forge to fit that requirment. i am planning on lining with at least 2 inches of kaowool and using a few firebricks as a floor. ive scene that most are saying in the range of 300-400 cubic inches is about what these little guys will heat up that high. if someone could give me a closer range so i can start finding possable containers. thanks iirc, 400ci would be too large to get welding heat from a 3/4" burner. I believe 350 would be the largest and even then, I think it would require the higher end of fuel consumption, imho Quote Link to comment Share on other sites More sharing options...
nick1018 Posted March 13, 2014 Author Share Posted March 13, 2014 Thank you very much dodge, this was the info i needed to start looking at possible forge bodies. thanks Quote Link to comment Share on other sites More sharing options...
nick1018 Posted March 14, 2014 Author Share Posted March 14, 2014 I have more or less settled on a design. i am going to use 2, .75 inch burners in a forge that is 8 inches wide, 8 inches high and about 10 inches deep. this gives me 640 cubic inches or about 320 cubic inches per burner. i will have the burners about 3 inches from each end of the forge, set about 3 inches from the top of the shell to the top of the flare. i will use fire bricks for the floor so there is something flat to put material on. the burners will be conected to 20 lb lp tanks using valve to limit the flow into the hose and a ball valve to control amount of gas into burner. i will post drawings when i get them made up. the lining will be between 2 and 3 inches of kaowool. Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 14, 2014 Share Posted March 14, 2014 Nick: 0.75" Reil burners need to be very well made and adjusted to bring 350 cu/in to welding heat because they're linear type NA burners. Excellent burners, just a little more limited. however, 640 cu/in isn't really out of range. I think your intended dimensions will make a good shape forge. We usually plan our first forge WAY too big or small. Good start. If you aim the burner closest to the door back a little it'll help prevent as much heat being blown out the door. A 2lb. tank will NOT run two 0.75" burners more than half an hour or so before freezing up. You can get around it by putting the bottle in the slack tub but the best solution is a larger tank, I run mine off a 100lb tank and it will freeze in a couple hours if the ambient temp is below freezing. I put a couple magnetic engine heaters on it and it's o-k-a-y. Sometimes at demos I use 40lb bottles and the slack tub. The thing you REALLY have to watch using a slack tub for a heat sink this way is keeping the bottle secure so it can't tip over. You REALLY don't want the bottle tipping over and sending a shot of liquid propane to the burners. That is a B-A-D-N-E-S-S thing. Frosty The Lucky. 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.