inazuma_x Posted September 1, 2008 Share Posted September 1, 2008 i know this is a pretty common theme but i had a quick search on this forum and didnt find much in the way of a full(ish) list of pros and cons of both forges. so i was wondering if we could get one going. coal: pros: more olde worlde cons: fuel can be hard to find and vary in quality, odor gas: pros: ? cons: harder to weld in? Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted September 2, 2008 Share Posted September 2, 2008 My gas forges won't weld reliably but my coal forge will so that's why I keep it around. If my propane forges welded every time, I wouldn't need coal at all - except maybe if I were working on something large that would not fit in the gas forge. Depending on what type work you are doing, this may not be an issue. Gas may not be such an advantage where coal or charcoal are readily available, but a lot of the country does not have readily available solid fuels. Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 2, 2008 Author Share Posted September 2, 2008 well i do wanna do alot of welding...in particular pattern welding...is this impossible with gas? Quote Link to comment Share on other sites More sharing options...
maddog Posted September 2, 2008 Share Posted September 2, 2008 Coal is dirty. The smoke eats your clothing and the soot will foul your shop. Its not that good for your lungs. It can be hard to find suitable coal and you have to have somewhere to store it. The fire needs constant management and periodic cleaning. Its very easy to burn the work in a coal fire A coal fire is very versatile. It can be constructed to suit the work. It has no trouble reaching welding heat and can go from idle to welding in a few mins or less. The chemistry of the combustion is very kind to the steel and welding is a cinch. Its easy to get a localized heat which means you dont have to work with 8" of white hot steel and you can do a weld without ruining other delicate parts of the work. In a coal fire, the fuel is the refractory so you dont have to try and heat a chamber to working heat. I will add some notes on propane forges later Quote Link to comment Share on other sites More sharing options...
Jymm Hoffman Posted September 2, 2008 Share Posted September 2, 2008 (edited) Gas: Pros: much cleaner, especially in and around the shop. Can forge weld in my gas forges, in a matter of minutes. I have not had coal in my shop since 1993, that is how much I like propane. Plus, I do not have to go get it, shovel it, it is fast to start, fast to shut down (turn off and walk away,) I don't blow black buggers out of my nose and I think I am healthier. Cons, can restrict the size of projects, with creativity and knowing how to build them, I don't have any problems. The picture of me working on a trunion plate made from 1/2" X 3 1/2" HR steel, (canon barrel rests on this on top of a field carriage,) was made in my smaller 2 burner forge, a larger project than many will work. The shell is from a 20 pound propane tank. The larger 3 burner forge shell is made from a cut down 100 pound propane tank. It has a side cut out for shapes that won't fit straight through the front. I have since made a smaller cart to keep the 2 burner mounted so I roll one out of the way to use the other. The smaller one gets to welding temperature faster than the larger one, only a few minutes difference. I also posted photos of burner tips and manifold systems. The manifold made of only T's works better, but I can make both types work. Edited September 2, 2008 by Jymm Hoffman Quote Link to comment Share on other sites More sharing options...
civilwarblacksmith Posted September 2, 2008 Share Posted September 2, 2008 This is from the WebHome < BlacksmithInfo < TWiki that the guild I belong to host as an public domain site Blacksmith Guild of Central Maryland This was written by Albin Drzewianowski, who is in charge of our Blacksmithing Academy.Coal Forge vs. Propane Forge by Albin Drzewianowski In order to blacksmith, you basically need 3 things: heat, anvil and hammer. Let's address how you are going to heat up your steel. Generally speaking, you have 2 options: coal or propane gas. The ideal blacksmith shop would have both. Each type of forge has positive and negative features. I have to admit, I am biased toward the coal forge. Overall, I think it is more versatile. However, it has one really major negative feature - COAL SMOKE. Many blacksmiths, due to their circumstances, neighbors, etc, can not be generating coal smoke in their home forges. (We will discuss how to minimize coal smoke when we talk about fire management in a future installment.) Also, if you are forging inside, you must have a chimney. So if you are going to use coal, you need to deal with the smoke issue. When you situate your blacksmith shop, take into consideration, if possible, which way the prevailing winds blow. Will the smoke be blown toward your neighbor's house?? If you forge in your driveway or patio, which way will the smoke blow?? Remember, the smoke contains soot which can precipitate out down wind. When you build your blacksmith shop, if you use a coal forge you will need a chimney. It should be, at a minimum, 10" round, 12" is better, or the equivalent if square or rectangular. In my opinion, 8" stovepipe just will not handle the amount of smoke generated when starting up the fire or when adding fresh coal to the fire. Some people add a blower to the chimney to help exhaust the smoke. Just remember, that coal smoke is quite corrosive and if you put a fan or blower inside the stove pipe, it probably won't last. You need to mount the blower out side the pipe and direct the output from the blower into the chimney to push or pull the smoke along. Having a good draft in the chimney is critical to successfully dealing with the smoke from your forge. The positive features of a coal forge: You can fit pretty much any size piece of metal into the fire. You can get a localized heat. It is easier to forge weld (in my opinion). You have less scaling compared to a propane forge. Adds less heat to your shop in the summertime, as compared to a gas forge. The negative features: If you are not careful, you can easily burn up your work. It is difficult to have multiple pieces in the fire at the same time, for example when making keychains, you want to have a half dozen or so in the fire at the same time. Tends to be dirty/sooty. You get more dirty and your shop is more dirty. Can be difficult to obtain good blacksmithing coal. Coal takes up more storage space. Takes longer to get the fire going. A little more of a fire danger since this is an open flame. Pretty much all of the above applies to using commercial coke vs. coal. There are a few differences. With coke you still need a chimney, but the smoke is not objectionable, the way coal smoke is. You will need to have a steady flow of air into the fire, or the fire goes out. Forging with coke if you use a bellows or hand crank blower is problematic. Coke burns hotter, this can be both a positive and a negative feature. You need a heavier/thicker fire pot. Coke burns cleaner, preferable for forge welding. Commercial coke in a good size for blacksmithing is even more difficult to locate than good blacksmithing coal. Now, looking at the propane forge. Positive features: The propane forge is more convenient. Don't need a chimney when used indoors. It fires up quickly and you can be ready to forge in as little as 5 minutes. *Can be set so that your work does not burn up. You can have a lot of blanks in the forge at the same time; very handy when making multiples of small items, like hooks or keychains. Propane is readily available pretty much everywhere. Adds more heat to the shop in the winter time. Overall cleaner. Don't need the storage space you would need for coal. More portable.Negative features of a propane forge: Limited to the sized of the forge box, can be difficult to get large or assembled pieces into the Forge. Can't get a localized heat, generally the entire piece is heated up. Need to use tongs more than when working with coal. More difficult to weld. If used inside, there is a greater danger from carbon monoxide. The steel scales more. Some say that the scale from a propane forge is more difficult to get off than the scale from a coal forge. Adds more heat to the shop in the summer time. Unless you build it yourself, probably more expensive to purchase. The positives and negatives of propane gas apply pretty much to natural gas with the following differences. Natural gas does not burn quite as hot as propane. You will need to run pipe from where the natural gas comes into your property to your blacksmithing area. Does not have the portability that propane as. Sometimes residential natural gas service is at too low a pressure. Some blacksmiths have had hassles with the local gas company over pressure and regulators. Each blacksmith has to look at his/her own circumstances and weigh the pluses and minuses and determine what will work best. Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 2, 2008 Author Share Posted September 2, 2008 wow...that is some serious kit...for the future i think i would attempt a custom gas forge...but for now i think an off-the-shelf model would be a better starting point...dont wanna go bleve'ing my house... Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted September 2, 2008 Share Posted September 2, 2008 IMHO, I think this should be a "sticky" - it is a very good summary of the various fuels and advantages/disadvantages to each. Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 2, 2008 Author Share Posted September 2, 2008 i agree! along that line...what do you guys think of these burners?Hybridburners.com Products $185 for the 1" forge burner nozzle doesnt seem like alot compared to the $2000 i've been quoted for an imported, off-the-shelf gas forge... Quote Link to comment Share on other sites More sharing options...
Jymm Hoffman Posted September 2, 2008 Share Posted September 2, 2008 (edited) Why would you not want to try to build one that would cost less and possibly get hotter faster without these expensive burners? Or is it that you just want to build with these? If you want to build with these, then just buy them and start building. Many of the commercially built ones that are natrually asperated with more than one burnere can forge weld if you run high enough pressure. However, they use more fuel and take longer to get to welding temprature than those I have pictured. Edited September 2, 2008 by Jymm Hoffman Quote Link to comment Share on other sites More sharing options...
Alwin Posted September 2, 2008 Share Posted September 2, 2008 I am curious about whether people have had much luck with drop the tong welds in a propane forge, and if so how they set the forges and steel up to do it. I also wanted to add that I use an 8" pipe for my side draft coal forge and my shop is smoke free even when I'm starting the fire. One just has to keep coke in the middle and coal on the edges. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 2, 2008 Share Posted September 2, 2008 As to welding in a propane forges a *LOT* of the top blademakers use nothing but propane for welding up pattern welded billets. As I recall James Hrisoulas uses an aspirated propane forge for his welding and he does a *lot* of it! He's not at sea level either. I have always been bemused that folks say that propane scales more than coal. If so then they need to adjust their burner! I tend to tweak my burner so that very little scale at all forms until I take the metal out into the open air. Another possible issue is that folks get used to leaving a piece in the propane forge for long periods of time serene in the knowledge that it won't burn up---though I recently melted a piece in my gasser. Anyway if you leave the piece in while doing other things of course it will build up more scale! Coal forges are a lot more impressive at Demo's though and just like having a ringing anvil what brings in a crowd doesn't do you any good healthwise... Quote Link to comment Share on other sites More sharing options...
bipolarandy Posted September 2, 2008 Share Posted September 2, 2008 Inazuma, the hybrid burners are very good and probably the best of the aspirated burners sold. I use two of the 3/4" t-rex on my forge, but like Jymm said , they take much longer to heat up and use more fuel then a well made system like his. The appealing part of naturally aspirated forges is the control of the flame from reducing to neutral to oxidizing which might be important for some people, but overall is kinda useless. Quote Link to comment Share on other sites More sharing options...
Ratel10mm Posted September 2, 2008 Share Posted September 2, 2008 Inazuma, there's probably a BP on building gas forges here. But as Thomas says, they're very popular in the bladesmithing fraternity. Check out the BP's here, and also search Don Fogg's site and British Blades. You'll find a heck of a lot of ideas. Many of my friends have even made thier own burners, and one or 2 use burners from tar torches (the sort you use to seal tar roofs). Also I recall that burners can be had in the U.K. for a bit less than the $187 you've been quoted, but I'm hazy on that one. Drop me a line if you want to talk it through - I've not yet built mine, but I've been paying attention! ;) Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 2, 2008 Author Share Posted September 2, 2008 Inazuma, the hybrid burners are very good and probably the best of the aspirated burners sold. I use two of the 3/4" t-rex on my forge, but like Jymm said , they take much longer to heat up and use more fuel then a well made system like his. The appealing part of naturally aspirated forges is the control of the flame from reducing to neutral to oxidizing which might be important for some people, but overall is kinda useless. does it not help in controlling scale? do you have any pictures of your rig? would love to see those burners in use! Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 2, 2008 Share Posted September 2, 2008 Actually aspirated burners are much trickier to adjust for atmosphere than blown burners. Blown burners do not depend on the fuel gas stream to entrap the combustion air and so you can run them anywhere from zero with the entire flame plume basically coming out the door of the forge to so oxidizing you can actually use it as a texturing process---I textured a dragon's head this way once running the forge very oxidixing and then chipping off the heavy scale leaving a finely pebbled texture on the steel. I have both types of forges and so have experience with both types of burners. Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 2, 2008 Author Share Posted September 2, 2008 (edited) i did like what Jymm did with the manifold and the whole rig looked very industrial and kinda steam-punkie...but to be honest it kinda scared me. i spose if you turn the blower on first and then the gas...and turn the gas off first and then the blower the risk of explosion would be reduced... i am really only familiar with coal forges and although i am excited about getting into gas forging the prospect does frighten me slightly...hence my tendency to look for off-the-shelf components rather than trying to slap something together myself when i am not really aware of the risks to the same level as i am with coal... another thing i've been wondering about is how you attach the kaowool to the inside of the modified gas cylinder? is there a need for the nozzles of the burners (as in jymm's forge) to be replaced? i would imagine the ends would become burned... Edited September 2, 2008 by inazuma_x Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 3, 2008 Share Posted September 3, 2008 (edited) hmm steampunk, now you make me want to add a bunch of damaged guages to my system in dummy positions with the indicators redlined... in most tube forges you bend the kaowool into a circle and place it in the forge the natural arch holds it in place. Yes the ends of the burners do degrade with time. Designing them to be easily replaced is a good idea. To light my blown gasser I 1: turn on the blower; but with the air gate closed 2: light a wooden match and place it at the front entrance to the forge 3: turn on the gas 4: after it lights add air until I get the proper mix for what I wish to do. (Often it start at neutral/oxidizing for fast heating of the forge and then go towards reducing for blade forging once the forge is hot.) Edited September 3, 2008 by ThomasPowers Quote Link to comment Share on other sites More sharing options...
bipolarandy Posted September 3, 2008 Share Posted September 3, 2008 hmm steampunk, now you make me want to add a bunch of damaged guages to my system in dummy positions with the indicators redlined... ) Best post ever Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 3, 2008 Author Share Posted September 3, 2008 hmm steampunk, now you make me want to add a bunch of damaged guages to my system in dummy positions with the indicators redlined... haha well the big valve and pipes was what gave me the steampunk impression...in most tube forges you bend the kaowool into a circle and place it in the forge the natural arch holds it in place. oh thats good to know...i was imagining something a little less rigid...guess its alot like fibreglass in the handling department?Yes the ends of the burners do degrade with time. Designing them to be easily replaces is a good idea. to this end would it be a good idea to weld the screw ends of some pipe on the inside of the forge so the nozzles can be screwed on/off as needed? how do you deal with it? in jymm's forge they appear to be welded in place... Quote Link to comment Share on other sites More sharing options...
Jymm Hoffman Posted September 3, 2008 Share Posted September 3, 2008 Drop tong welding is no problem, it is like any other forge welding. By the way, the forges that I put a water gate valve on the air line and needle valve on the gas line give me the most control. I make these forges to get really hot really fast, so the valves help me cool them down for certain jobs. The "official" way to light a blown forge is to use a small amount of paper waded up. Light the paper, put it into the forge, turn on blower, turn on gas. I set up my forges up so the blower is on a light switch and the gas valve is down for the off position. That way up is on for both and down is off for both. It is also very natural to turn the gas off before turning off the blower since the light switch to the blower is below the gas valve. Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 3, 2008 Author Share Posted September 3, 2008 is there a need for a waste gate (or blow off valve) on the section of pipe from the blower to the water gate valve? i would have thought the pressure buildup behind the water gate would be substantial...though this could just be me over engineering things again :) Quote Link to comment Share on other sites More sharing options...
Jymm Hoffman Posted September 3, 2008 Share Posted September 3, 2008 Over engineering for the blowers I use. For me the more I engineer and complicate things, the more things go wrong. Keep it simple works best for me. I use at least one of these systems most every day. The small one I call Ugly Betty and the lareger one Bertha. I could pretty them up, but don't have the time. My goal is to make them work, and get them working so I can make money with them. Quote Link to comment Share on other sites More sharing options...
inazuma_x Posted September 3, 2008 Author Share Posted September 3, 2008 how many cubic feet per minute do your blowers push? Quote Link to comment Share on other sites More sharing options...
Jymm Hoffman Posted September 3, 2008 Share Posted September 3, 2008 Blacksmiths Depot | 112 CFM Blower These are the blowers I am using, they work great and 1 1/2" black pipe slip right into the opening as shown in my previous photos. Quote Link to comment Share on other sites More sharing options...
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