Dave Hammer Posted November 22, 2012 Share Posted November 22, 2012 I recently put up a new video on YouTube showing how I build one type of propane forge I use. http://www.youtube.com/watch?v=PbvG4vVJqCw&feature=channel&list=UL This video shows only how I build the shell of the forge. I expect to be putting up another video within a couple weeks showing how I make the refractory floor for it, line the forge with thermal blanket (with a ceramic coating on the blanket), and shape Insulating Fire Brick (IFB) to be used for the doors and horizontal opening cover. Quote Link to comment Share on other sites More sharing options...
jsmbrown Posted November 27, 2012 Share Posted November 27, 2012 Very nice video. Thank you for sharing. I love the design. It allows you to forge long pieces like knives and fat pieces for decorative depending on the opening you close. Best of both worlds. I have a 5 gallon air tank I might try for this design. I hope it is thick enough. The tank you use looks very thick. Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted November 29, 2012 Author Share Posted November 29, 2012 I like the forges I build to be heavy so heat or rust doesn't destroy anything. I have used lighter cylinders. The issue with using a light cylinder is flexing of the "C"....., something you don't want. To avoid flexing, weld a stabilizer between the door channels (on the "C" side) and the "C" shouldn't flex (assuming the stabilizer is heavy enough not to twist or flex). A five gallon tank would be a large forge for me. It would take a lot of fuel to get to and maintain forging temperatures. Almost all the forging I do can be done with my 8" (outside diameter) forge, which is very economical to use. When I need to heat a large object, I put together a free form forge using light fire bricks. I will be putting up a video later about free form forges. I don't see a way to add a photo during an edit of an existing post. My next post has a picture of a free form forge I used to heat a 4 inch diameter pipe. Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted November 29, 2012 Author Share Posted November 29, 2012 Free form forge... I will be putting a ceramic refractory coating on the brick (for more efficiency and longevity) in the video. I did find the way to add an image during an edit (use full editor). Quote Link to comment Share on other sites More sharing options...
jsmbrown Posted November 29, 2012 Share Posted November 29, 2012 I definitely want efficiency. Perhaps I will use an old freon tank and try adding the stabilizers. It looks like you use atmosphere burners. Are you able to get to welding temps with them in your C shaped forge? Would a blown burner be more efficient and worth the extra cost? Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted November 30, 2012 Author Share Posted November 30, 2012 I don't do a lot of forge welding, but... yes, I have easily forge welded in my forges (layered billets, faggot welds and other types of welds). I don't do enough forge welding to be good at it. The burner type is not the only issue. I believe effective forge lining (including a refractory coating, if thermal blanket is used) is as important (including what is used for the floor), if not more important than the type of burner you use. Also, the heat needs to be contained effectively (no excessive openings). I have played with blown burners, but always come back to atmospheric. Some claim higher temps with blown burners, but I cannot testify to that (others may). I'm not sure about efficiency, but remember... it's the BTUs that do the work, not the method of delivery. I believe the management of those BTUs is the key to success. The blown burner itself is not necessarily more expensive to make (buying blown burners, such as ribbon burners can be expensive). Finding a blower that works for you can be both challenging and expensive (unless you get lucky at tailgating or a yard sale). The type of burner you use can affect forge design. The type of blown burner affects the type of blower you need. Some blown burners need a "pressurized" environment most blowers will not provide (think plenum). Sometimes a minimum pressure, with a range of pressure is needed to get higher temps (think inches of water column, using a manometer to measure pressure). I have no doubt the "C" design will work effectively with either type of burner (the burner holder may be different). If you want to try a blown burner, find a design which includes a specified blower (by name and model) and make (or buy) that one. In my opinion, anything else is a crap shoot till you have success. Quote Link to comment Share on other sites More sharing options...
AJAX Posted November 30, 2012 Share Posted November 30, 2012 I have an old oxy tank around, I'm not sure how safe it is to cut into the tank. I don't even know if it has in gas left in it. How should I go about doing this safely? Quote Link to comment Share on other sites More sharing options...
Dave Hammer Posted November 30, 2012 Author Share Posted November 30, 2012 I have an old oxy tank around, I'm not sure how safe it is to cut into the tank. I don't even know if it has in gas left in it. How should I go about doing this safely? I can't offer advice about this.... I never start with a tank with a vave on it. I buy old tanks at a steel recycling yard. The valves are already off them, so I know they empty and safe to cut. You could call a business that sells oxygen (like a welding supply store) or visit a steel recycling yard and talk to someone about how to make them safe to cut. Others may chime in here.... Quote Link to comment Share on other sites More sharing options...
metalanton Posted January 9, 2013 Share Posted January 9, 2013 thanks Dave so much for this contribution, extremely thorough, informative, and a quite flawless design, I really really am looking foward to the insulating the forge video as well! Quote Link to comment Share on other sites More sharing options...
C.D. Mitchell Posted January 10, 2013 Share Posted January 10, 2013 The safest way to cut on a tank is to not do it at all. If you're wondering why, spend 30 seconds on youtube and google looking up explosions from welding and cutting on drums and tanks that had flammable gas or liquid in it. A lot of people have been hurt or killed doing stuff like that, so do yourself a favor and don't add to the statistics. Even filling a tank with water doesn't clean it out enough to make it completely safe. With some flammable liquids and gases, even the smallest trace left in a tank can create enough fumes to cause an explosion. Probably not a lesson you'd want to learn the hard way. There's always other ways to get a pipe. Quote Link to comment Share on other sites More sharing options...
Backwoods Blacksmith Posted January 11, 2013 Share Posted January 11, 2013 If the valve is open on an oxy tank and nothing comes out it is empty. I recently modified a 30 gal propane tank to add to my air compressor. I ran a hose from the exaust from my quad to the fully opened valve. I then drilled a 1/4 hole in the tank where I wanted to weld a coupling. After a minute or so to fill the tank with exaust, using a hole saw, I cut the right size hole in the tank and then welded my pipe fitting. Exaust will force out any propane fumes and oxygen, blanketing the atmosphere with a nonflamiable gas. This method is commonly used to weld up fuel tanks with no problems. I am sure I will hear a bunch of nonsence about this but it has been done for years with few problems. This will work very well on an oxy tank that has no pressure. This seems to be what was used in the video with the valve removed. Open the valve and you will have the same situation. If you want fill it with water, forceing out any gas. Once the first section is cut the the atmosphere is common. Wear safety glasses, wear gloves and long sleeve shirt. Maybe ear plugs. Safety concerns are valid and should be thought out. There are many ways to safely do things that are inhearently hazardes. lighting compressed gas in an enclosed area is dangerous, but it is done every time a gas forge is lit. Use you head, protect youself, and get the job done. Quote Link to comment Share on other sites More sharing options...
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