Ravenshurst Posted March 6, 2015 Share Posted March 6, 2015 Hi all. New to the site and to blacksmithing. I have always wanted to learn, but never had the time. I finally have some time, so I am taking a blacksmithing course at the community college. Time to build a forge. After doing some online research, I have decided that a forced air gas forge is what I want for my first project. I have a propane tank which, when cut, will have a length of approx. 12 inches and a diameter of 12 Inches. Approx internal volume 1357 cu inches without insulation. So....insulation recommendations? Material, thickness/weight? If 1 burner is sufficient for 350 cubic inches, how many burners should I plan for after the proper amount of insulation is added? At this time I don't have any preferences as to single or double burner, but as that may change, I would like to build this forge for the future, even if it is overkill now. As I know nothing about building a forge, any and all advice is greatly appreciated. Thanks ! Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 6, 2015 Share Posted March 6, 2015 Welcome aboard, glad to have you. If you'll put your general location in the header you might be surprised how many of the IFI gang live within visiting distance.Two layers of 1" 8lb. Kaowool or the equivalent ceramic blanket refractory works nicely and will reduce a propane tank to a good volume. A good kiln wash is a good idea on several fronts: First it will help prevent fibers from the ceramic blanket becoming airborne and presenting a breathing hazard. It won't cause mesotheleoma but silicosis is a possibility. The other main reason for a good kiln wash is to help resist chemical and mechanical erosion, Welding fluxes are almost all strong bases and at welding temperatures they're strong caustics. Welding flux at temp tends to dissolve silicates like hot water through sugar and ceramic blanket is like cotton candy.How you build end walls and doors is up to you, there are a number of good ways. Determine the internal volume and that'll tell you how many burners you'll need. How many and what size burners is determined by a number of things, volume being #1. As or more important is the shape of the chamber for a simple example let's say it has 700cu/in. By the most basic calc it will need two 3/4" or one 1" NA or gun burners. What if it's 30" long and about 5" in dia.? If you used a single 1" burner it would develop very uneven heat. two 3/4" burners will be more even but four 1/2" burners will have such even heat you could use it for a heat treat oven.Just stuff to think about, do NOT decide anything till you've given it some thought, drawn some dimensioned drawings, graph paper is excellent you don't need the cadd software or a drafting table, T square, etc. Just good enough drawings you can do a little paper roll playing.I'm not a huge fan of propane tank forge bodies. They work fine but it's a lot more work than necessary, heavier and harder to modify. I really prefer SS stove pipe if a cylindrical forge is what you want. A simple brick pile forge is not only easy to make and repair you can change the shape as necessary. I'm a huge fan of versatile.Give it some more thought and give a holler if you have more questions.Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Ravenshurst Posted March 7, 2015 Author Share Posted March 7, 2015 Frosty: Thanks for your advice. What is kiln wash? Unfortunately I haven't run across that in my surfing yet. Is that a semi-liquid/cement type of slop to plaster the interior walls with? I am thinking of using fiore brick on the bottom for a flat floor. End walls: I was going to cut the top/"front" wall more or less flush, to make it easier to get inside the tank for plastering. I am thinking about a door in the back for a pass-through. I need to do a lot more research before I start building. Thanks again. Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 8, 2015 Share Posted March 8, 2015 Kiln wash is a material painted on or soaked into or ? there are lots of ways to apply it but it protects the inside of kilns, furnaces and forges from the conditions on the fire contact surfaces. The ceramics suppliers have many formulae as different glazes, pigments, etc. react differently to refractories, kiln furniture, etc.I still have part of a 1lb. /pint can of ITC-100 which is a zirconia silicate flour in kaolin clay and is probably one of if not the best known kiln washes amongst blacksmiths and metal industries. It's very resistant to high temp caustics like molten borax and it's a high efficiency IR reflector so more heat stays in the forge. The down side is price, last time I checked it was well over $100.00/pt plus shipping.Our club bought zirconium silicate sand and are making our own kiln wash. Unfortunately it's just plain hard to get a 50lb. block of kaolin up here right now so I just sifted out a little of the fines from a bag of 3,000f castable refractory to use as the binder. Time will tell how it works.Kiln washes are NOT plaster, they're like old type whitewash, thinner than ceramic slip. Wet the interior to prevent the wash from flash drying and flaking and brush the wash on. Thick coats tend to flake if you're not lucky so apply thin coats. Let it dry, then wet then apply another coat but not a lot of coats. More in NOT better.Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
WayneCoeArtistBlacksmith Posted March 8, 2015 Share Posted March 8, 2015 Look at my tutorial on the Forge Supplies page on my web-site, www.WayneCoeArtistBlacksmith.com. The Build a Gas Forge attachment was written when I was doing atmospheric forges. The Ribbon Burner attachment is John Emmerling's tutorial on building a Ribbon Burner for a forced air forge with other information that I collected from the forums and from Pine Ridge Burners. You can use the Build a Gas Forge attachment for the general instructions and adapt for the Ribbon Burner. I use a Ribbon Burner now and run the forge at about 1/2 pound pressure and get up to forge welding temperatures very easily. I have more trouble keeping it from getting to hot than not getting hot enough.Call or e-mail me if you would like to discuss this further. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 8, 2015 Share Posted March 8, 2015 Note that I and all my friends buy our refractories from Wayne at Quad-State and have been most pleased with his stuff! Quote Link to comment Share on other sites More sharing options...
Ravenshurst Posted March 9, 2015 Author Share Posted March 9, 2015 Frosty, thanks for the help. Wayne, GREAT tutorial, thanks a lot. Thomas, thanks for the advice. 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.