ytuyuty Posted March 7, 2016 Share Posted March 7, 2016 I put my gas forge on a portable stand with wheels. I can wheel my forge out into the driveway and hammer away. No more bending over. It's working out perfectly. Link to comment Share on other sites More sharing options...
JME1149 Posted March 7, 2016 Share Posted March 7, 2016 Just add a little tray underneath to put the propane tank on and you're good to go. I like it. Link to comment Share on other sites More sharing options...
Frosty Posted March 7, 2016 Share Posted March 7, 2016 Nice. I picked up a steel serving tray kind of cart thing on wheels a couple years ago at a yard sale. There were a couple things on it I was interested but they wanted everything gone so I made them throw in the cart. I throw a piece of plywood on the spreaders for a shelf underneath. It's ugly, the wheels squeak, one is a wobbler and I love it. It sure as winters are long here doesn't look near as nice as yours. The longer you use it the better you'll like it. Frosty The Lucky. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 7, 2016 Share Posted March 7, 2016 Hi Harry, The stand looks fine to me, but please don't let anyone talk you into positioning a propane cylinder underneath a heat source; that's like begging for trouble with your local fire department. People see propane cylinders placed under barbecues and some shop heaters, and assume doing so with homemade heating equipment is okay; it's not. The commercially built examples I used are "grandfathered in" exceptions to national and local fire codes; if not, they would not be allowed under today's fire codes. Link to comment Share on other sites More sharing options...
ytuyuty Posted March 7, 2016 Author Share Posted March 7, 2016 Notice the very long gas line. I keep my propane cylinder as far away from the forge as possible. Link to comment Share on other sites More sharing options...
Frosty Posted March 7, 2016 Share Posted March 7, 2016 I run mine off a 100lb. cylinder and a 8' hose so it sets back a ways. I highly recommend keeping the tank back aways and paying close attention to the relation of rubber hose and forge heat. I run the rubber hose to a manifold and run copper lines to the burners. It makes zero difference if the copper gets HOT other than maybe improving mixing and combustion. I haven't experimented with preheating the propane though it's common practice where efficient BTU output counts. Frosty The Lucky. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 9, 2016 Share Posted March 9, 2016 Preheating propane was a long running debate on the various home casting groups; I didn't get involved, because I felt it was two steps back for one step forward, trading away safety for some increased flame temperature; not my kind of deal. Link to comment Share on other sites More sharing options...
Latticino Posted March 9, 2016 Share Posted March 9, 2016 I've never heard of preheating the fuel source in a burner system, and agree with Mikey that it sounds a bit dangerous. However I have certainly heard of using a heat exchanger to preheat the air for the burner with the other side of the equation being the heat being thrown away in the flue gasses. For an industrial or light commercial application, where the forge is running continuously for long shifts this might be worth considering, though it adds a lot of complication to the design. I find it hard to imagine it being a worthwhile trade off for a hobby smith. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 9, 2016 Share Posted March 9, 2016 With one, and only one, exception. preheated air must be introduced into a flame nozzle (usually ceramic) separate from the fuel, which means no mixing chamber other than the nozzle. The generally accepted central principle behind preheating the air is that, being about 80% nitrogen, a boost in flame temperature comes from the combustion process being saved the energy loss from heating all that useless nitrogen content. There are various other claims made for other preheat schemes, which are dear to the people pushing them, but which are just as enthusiastically disputed by others. Getting back to the single exception: There was an all stainless steel forge burner system developed at a national government laboratory, which preheats both fuel and air in its mixing chamber. Although there are accounts of this burner system's success, and no accounts disputing it, the inventor himself pointed out that the rather expensive tubing had to be replaced every few months, and that it had to be stainless steel; not such a good deal overall. Certainly, some warming of propane that is barely above freezing temperature in winter is worthwhile and safe. However, one of the reasons cold propane is my preference is the very convenient refrigeration effect, which I depend on for added safety in my burners, which set a little way inside of very hot equipment. Frosty likes to mount his burners on the outside of heating equipment and use an opening in the brick to form a flame nozzle; this scheme isn't going to need as much cooling of the burner, and so with his system you might push the warming a little more. Why warm the propane at all then? Because tiny pieces of frozen propane can be blown into the burner if it isn't kept warm enough to be pure gas; they disrupt the flame, and if ignored, could snuff it out. In my world safety is first, performance is second, and most other factors a distant third. Okay, frozen, is the wrong word; liquid is the right word. Link to comment Share on other sites More sharing options...
ThomasPowers Posted March 9, 2016 Share Posted March 9, 2016 wow none of you have seen the old gasoline torches or the old white gas camping stoves or a propane fired balloon? All of which preheat the fuel to turn it from a liquid to a gas... Link to comment Share on other sites More sharing options...
Frosty Posted March 10, 2016 Share Posted March 10, 2016 A few years back, when I was still tinkering the T I spent quite a bit of time on websites for English made products that preheated the propane in different ways. One really impressive little unit wasn't much larger than a pack of cigarettes and used a battery powered arc to superheat the propane before injecting it into the combustion air. The video demo showed torch welding mild steel with an AIR propane torch with a flame smaller than a Bic lighter. There were larger units including furnace burners that brought the propane to temps in excess of 2,000f. The numbers they were claiming was the efficiency was much greater than preheating the air. They cited hot air balloon burners as primitive versions of the principle. Something that struck me was how much safer it was than preheating the combustion air. A flammable air propane mix flashes around 1,000f IIRC. so it's not possible to inject propane into an air stream in excess of that temp and get a clean burn as it will combust before it's thoroughly mixed. Superheating the propane on the other hand causes it to expand to the limits of the available air much faster than the explosive wave front. Superheated propane also mixes exponentially more easily than cold. Maybe Ron still has the link but he wasn't interested and that was I don't know how many computers ago. At this point my memories of the super burners are anecdotal at best. Frosty The Lucky. Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 13, 2016 Share Posted March 13, 2016 No dispute here. But what someone designs into a commercial product, and what it is safe and sane to recommend that newbies try are worlds apart. I built all kinds of little safety features into my early burner designs, and still got presented with changes that gave me the willies; all by people claiming to have built their burners "exactly per my instructions" Link to comment Share on other sites More sharing options...
Mikey98118 Posted March 13, 2016 Share Posted March 13, 2016 Thomas, Liquid fuel burners, especially gasoline and kerosene, are an interest of mine. I spent some time researching gasoline blow torches on the net, and purchased one of the the new Chinese steel head blow torches; will be experimenting with it this summer. Gasoline is a fuel rated at a little higher energy density than propane, yet the accepted figure for a gasoline flame is only 2000 F degrees, which is why I'm only beginning experiments with it. Personally I'm counting on figuring what exactly is wrong with these flames, and coming up with much higher heat figures, but tools are as tools do; if someone figures out the underlying problem great; if not, than it's just another dead end research project. Link to comment Share on other sites More sharing options...
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