Forge fuels

[hellbound911]

what are you planning to do with your forge? that dictates what type of fuel you'll want to use.

Propane, more expensive overall but heats up extremely fast. So if you only have short periods of time to work with the forge propane is likely your better option, even if its typically more expensive. Will reach forging heat for non-stainless damascus, can weld damascus steel if its a blown burner, venturi burner will weld but forge needs to be well insulated.

Coal, I've used limited amounts of it others have mentioned the different types. Coal will get hotter and typically is cheaper to use if you have a local supplier of it vs propane. takes longer to heat up to use but costs less in the long run. It will need a vent hood due to smoke and fumes.

wood and as mentioned nuts can work as well, they have a harder time forge welding due to lower heat compared to coal but they will forge anything and can forge weld but takes time.

Coal and wood need a blower for it to work, hand cranks work well but you'll need to learn how to manage that. A hand crank gives you a bit more precise control over the temp when you get used to them. A fan can work on a coal forge as well, it needs to be a strong fan as it must blow air through the coal to heat it up so squirrel cage fans don't do well in this application, where as they do well with propane.

[Dantheharleyman99]

Sorry for the confusion about the power plant fuel type I stated earlier in this post, I was conveying information given to me by a friend who worked at a nuclear power plant that also ran coal burning power systems. There could have been a mis communication. None the less... I have learned that the type of hard fuel used (coal/wood/charcoal.etc) is not as important as the forge it's used in.

I have run hard coal, soft coal, wood, and both lump and briquette charcoal in my forge! All have preformed well with some modification to the fire pot and air volume. When I built my forge I made it as versitile as I could, I can change my fire pot depth from 2" to 6" by changing plates in the pot. I can also adjust my air from almost nothing all the way to category 5 hurricane speeds.

The second most important thing is fuel size and quantity. With clean coal I can run my 3" depth plate and only run the fan when there is material in the heat, sometimes I get 2-3 heats before I need air flow as long as I use pea size coal. For larger coal and lump charcoal I use the 4" plate to achive the same heat and the 6" plate for wood chunks and briquettes.
The simple math is.... More surface area of the fuel = more heat and a cleaner burn. So use the smallest sized fuel your forge will run.

I have used all the mentioned fuels for multiple forgings with respectable results. I do prefer good coal over all others for the fact it heats quickly and is very low maintenance compared to "dirty" coal ( pulling klinker) and wood or charcoal (burns very quick) but if you don't have good coal available you can use any of the fuels I mentioned and I'm sure many more I have not used with good results as long as the equipment is designed to run that fuel, people have been using whatever they could get to burn for thousands of years!

On a side note I wouldn't suggest using wood chunks if you have access to lump charcoal or briquettes. I was able to achieve forging temps with the raw wood chunks fairly easily by putting small log halves on the sides of my fire pot and building sort of a little log kiln but it eats fuel very very fast, that means you spend about half your day feeding the fire!
Wood lump charcoal works very well if you break it into smaller pieces but it also burns quite a bit of fuel to keep it hot... But it has a hidden advantage!... You can idle the forge as long as you want without loosing the fire and you can cook a steak on it when your ready for some grub!

Hopefully this helps clear some of the "can and can't use" fuels for anyone looking to forge but doesn't have access to clean coal.... There are many options available!

[AR. Hillbilly]

Ok y'all I have questions. I built my forge pot similar to DSW's. I bought a small bit of various sized coal from Vinita Ok. It worked perfect. The coal is random sized and produces some clinkers. I then bought what was called stoker coal. It was smaller and more even in size. It lights very easy. It all turns to ash and falls to the bottom and plugs off air flow. I can't get anything hot without poking it deep and verticle and only get the end hot. When the forge is very low on coal and the air can blast through it makes a very hot fire. but it will not reach high enough to heat 3/8' rebar. All the coal around the edges turns white and turns to ash and the ash falls to the bottom. You have to constantly dig down deep and stirr the fire to get any heat. This coal is a dull black/gray in color and comes from Wyoming. I'm just curious what it is? I got my hopes up because it's cheap and easy to get. They use it to heat chicken houses and green houses. One more thing. I light the Vinita coal with news paper and very little air.

[DSW]

Post up some picts of your fire grate in your forge thread. In my forge I have a clinker breaker, and by twisting it, I can drop the ash etc down into the ash collector down below where the air intake comes in. In my small hand pumped forge with a grate with holes, I have to manipulate the fire manually to get the ash to drop down into the ash collector. It takes a bit to get the process down and you have to do a bit more in constant maintenance of the fire. I take my fire rake and slide it back and forth to knock the ash down into the holes and keep the airway clear. You might also find bigger holes in the grate helps. The "holes" on the side of my clinker breaker are big enough I can easily get my finger in them, and they are about 3" long. That's a lot more room to "drop" things than a grate with a few 1/4" holes in it. Bigger or more holes may help with your issue.


I bet if you go over to IforgeIron and ask those guys, I bet some one there from out your way can tell you a bit more about what your coal actually is. There's a lot of very experienced smiths there who are willing to help as long as you make an attempt to search yourself for info 1st.

[drujinin]

Wyoming Coal is junk! It isn't as hard or old as Pennsylvania Coal or even West Virginia Coal. Do a GOOGLE SEARCH and you will find that the coal from Wyoming is almost a Lignite meaning it doesn't have the Carbon content as Eastern Coal. This is why it doesn't make heat and burns up rather quickly.

[AR. Hillbilly]

Thanks y'all. My grate is 3/8" thick. It has one slot in the middle that's 3/8" wide by 3" long and it has a 1/2" hole on either side of the slot. Plenty of the ash gets through the holes. I dump the ash gate every few minutes and get a big pile of ash and red hot coals. With the Oklahoma coal I get maybe a small handfull of clinker/ash after a few hrs of use. I have the forge cleaned out until I get better coal. I'll get a pic of the grate. I will join I forge iron. I got up at 3 am this morning and started reading on there. Again thanks for the help guys. I'm a beginner with very little knowledge on the subject. I hope this is something I can keep at for a long time.There are some things I'd like to learn to make and use in my work but right now I'm just trying things for the practice and learning some of the processes. I want to take classes but so far they haven't worked with my work schedule. We have a Blacksmith group near here that I plan to join in hopes of some learning. One of the members is a member of this forum and has been a big help. My reason for asking about the coal is so that I don't make the same mistake again.

[shortfuse]

Ok y'all I have questions. I built my forge pot similar to DSW's. I bought a small bit of various sized coal from Vinita Ok. It worked perfect. The coal is random sized and produces some clinkers. I then bought what was called stoker coal. It was smaller and more even in size. It lights very easy. It all turns to ash and falls to the bottom and plugs off air flow. I can't get anything hot without poking it deep and verticle and only get the end hot. When the forge is very low on coal and the air can blast through it makes a very hot fire. but it will not reach high enough to heat 3/8' rebar. All the coal around the edges turns white and turns to ash and the ash falls to the bottom. You have to constantly dig down deep and stirr the fire to get any heat. This coal is a dull black/gray in color and comes from Wyoming. I'm just curious what it is? I got my hopes up because it's cheap and easy to get. They use it to heat chicken houses and green houses. One more thing. I light the Vinita coal with news paper and very little air.

I posted some info on your "Wyoming coal" in one of your other threads, don't know if you have read it yet or not. The Vinita coal you have is what all our association members (some 140 of them) generally use. It is bituminous, soft, and suitable for smithing. It will occasionally build considerable clinkers, but you just have to notice if your airflow has to be stepped up to keep up your heat...a sure sign of clinkers. Shut down your fire, let it cool for a couple of minutes, then rake the coal out quickly and get the clinker(s) out. You can usually quickly rake the coal embers back in your firepot and pour the air to it to relight. DSW had some good tips on his firepot and clinker solution.

I get confused when you say one time you are using Wyoming coal, then you say you are using Vinita coal. I don't know exactly which one you are having problems with. They are two different coals. In my other post, I mentioned stoker coal. That is a SIZE description. Stoker can be bituminous, antracite or even sub-bituminous, being anywhere from 1" to maybe 3" in size, mostly used in power plants and heating.

Wyoming produces about 39-40% of the coal used in the US, primarily for power gen and heating. Reason is that it is more acceptable by environmental regs requiring low sulphur. It is mostly sub-bituminous, being lower in heat value than the bituminous Vinita coal, and softer. Therein may lie your problem using it for forging in that it may produce ash more quickly and readily than bituminous. Once again, stoker is not a type of coal but rather a size description. You may have been getting some erroneous info from the vendor.

Your ash problem blocking air flow is most likely due to small openings in your tuyere, or grating. Our club forge has an opening about 1/4" wide and 3" long. We get no ash buildup but will get a sizeable pie-shaped clinker after a couple of hours of moderate forging...time to kick it outa there. Make a poker out of rebar with a tip about 1/4" diameter and about 3" long. Use that to poke around on your firepot openings frequently to move the ash out. The Vinita coal we use is jet black and usually fairly shiny (not as shiny as antracite coal).

Give me a PM and I'll be glad to discuss the coal issue with you further, and maybe clear up some of your forging problems.

[shortfuse]

AR, I think you were posting while I was rambling on.....it may be that your coal size is small compared to your tuyere slot and you are losing some coal (red hot coals) along with the ash down the ash dump. At least you are getting rid of the ash buildup, it seems. If you have a lot of fines in your coal, it can either (1) be lost down your ash dump or (2) clog up smaller openings in your tuyere, but it seems you have a large enough opening, much like the club forge I mentioned above.

If you do have a lot of fines, you can sift them out with something like a 1/2" or 1/4" screen then put them in a spot on your forge table, wet them down (don't get water on your firepot!!), then pile them on the side of your fire and let the wet mass form a nice coke lump. Some folks say they wet their fines and make "coal balls" but mine never stick together, just fall apart.

[shortfuse]

AR, got your PM, everything is clear now. Thanks.