Gas forge

[Lukas Jacobs]

Can anyone help me ?
What is the difference in running costs for a gas and a coal forge ?
I am moving into a new building and thinking of building a gas forge instead of a coal forge .
I would appreciate all the advice I can get.

[Rich Hale]

Tough question as I don't kknow what the costs for each of those fuels run in your area. I use both and for the most part it is harder for me to get coal than it is propane. I like to forge with coal. I like the convenience of gas, turn the valve a bit, light it and in a short time I am up to heat. Its a toss up if either one is "better" than the other. One thing nice about gas is I can put several pieces in and not worry about melting one while I am working on another. Your call as to which will work for you..

[ironantlerforge]

Time is money as they say and for me, when I was looking into coal, It seemed like it just took a lot more time to maintain. you have to find a good quality coal source for starters then start the fire and work it a bit, deal with the smoke issue, clean out the clinkers and impurities, watch to make sure you don't burn up your work, and so on. I went with gas because it's quick, If I'm only doing a small project I can get the forge started in seconds, the propane company delivers, I can tap into the propane to operate a hand torch as well as a heater for my shop, and I have found the gas forges to be pretty efficient. I think I like coal better for forge welding but my experience with that is limited. When I get a bigger shop some day I think I will have a coal forge just for grins but the gas I believe will always be the workhorse of my shop.

[djhammerd]

Lukas.... I would recommend you plan for both gas and coal forges. If you have welding and scrounging skills, a gas forge can be built easily and very economically (at least compared to commercial models).

Nothing replaces the versatility and wonderment of working with a coal forge, and depending upon what you want to make/create/repair, a coal forge may be the only reasonable option (size and shape of some things are not gas-forge friendly). A gas forge is VERY convenient and more suitable for many things.

Assuming you have the necessary skills, I recommend building a small gas forge first, play with it, and learn what your needs/wants might be for one. The simplest one I've made is illustrated below. It has a 6 inch pipe body, with channel iron welded on each end to hold a soft firebrick. Soft firebrick is EASILY sawed to desired shape with any type of handsaw (be sure to wear a mask while doing it, and/or have ventilation (a fan) that blows dust away from you while cutting them). Some folks just set bricks in front (and back) of a forge, but I like to have them held in place without the likelyhood of falling (soft firebricks will sometimes break just falling over).. I also weld a small 3/4" pipe coupler on the bottom of the forge, so I can put the forge on a pipe petastal and not require a table for it (I cut the couplers in half so they are shorter, and I can use the forge on a table if I wish to).

One more thing.... a lot of folks like to make a forge light (by weight). Personally, I don't. Although light forges work fine, I like the tools I make heavy, so they can be moved around without being damaged.

Although it is not difficult to build them, if you're a little hesitant to make the burners, they (burners) can be purchased online without great cost (google Larry Zoeller, and look for forge parts on his website). For this small forge I used a single piece of 1-inch thermal blanket (like koa-wool) and (initially) a small semi-hard firebrick for the floor. The thermal blanket should be put in first (all the way around), then the brick nestled in on the bottom. Soft brick (cut to shape) could be used for the floor IF you are never going use flux in the forge. I have starting using flux resistant refactory for my floors, but hard brick is more economical and actually worked well. Only one brick is needed for the floor of this forge.

Good Luck....

[John B]

Do you have to use a flare on the end of the burner?

[Lukas Jacobs]

Thanks for all the helpful replies.
One more question. What is koa-wool ? Can I use something else ?

[djhammerd]

John B...

Aspirated burners do seem to work better with a flare on them. You can generally buy stainless steel flares (online and at tail-gating sales) for about 6-10 dollars, depending upon the source and the size of the pipe. If you are making your burners and want to save a few dollars, that flare can just be the next size pipe (about three inches long) slid over the burner pipe (and tightened to it with a set screw). The position of that kind of flare is a little more critical on the pipe (tune it outside the forge). A flare is almost a necessity if you are trying to "tune" the burner outside of a forge (a burner, outside a forge, without a flare doesn't want to stay burning), but that same burner will run in a forge without a flare.

Lukas Jacobs...

Kao-wool is a thermal blanket (insulation), which looks similiar to fiberglas insulation batting, but much denser (and heavier). It is used to line most commercial propane forges I am familiar with. Kao-wool is a brand name, among many (Dura-blanket is another brand). Thermal blanket comes in various grades and densities, varying in the amount of heat it can stand without damage (2300 to 3000+ degrees F). Most folks don't get their propane forges hotter than 2300 degrees, so the least expensive thermal blanket is usually used. Thermal blanket is usually bought in 1 or 2" thicknesses, 24 inches wide. The difference in prices for varying temperature ratings, may be substantial. Castable refactory (usually hard cement type coating) can be used to line an entire forge, but the forge will take longer to heat up to get ready for heating metal. A thermal blanket, with a sealing reflecltive coating (like ITC-100, or Plistix-900) on it, is the fastest heating environment in a forge. Thermal blanket (and its coating) must be considered a consumable, and needs to be replaced occasionally (once every couple years or so). A hard refactory, although it causes you to use a lot more propane to get to forging heat, should last for many more years before replacement is necessary (if ever). For me, the thermal blanket (and its time to forging heat) is more desirable for the walls and ceiling of the forge. I always use a hard floor, be it a soft brick, semi-hard brick, or castable (or ramable plastic) refactory (cement). When you shop for thermal blanket, fire bricks or castable refactory (or anything you are going to line a forge with, you shoud ask what maximum temperature the product is rated for (and already have a good idea what your actual needs are. If all you are going to do is heat metal for forging, 2300 degree rated materials are probably OK. If you are going to forge weld or melt metal for pouring, higher temperature ratings may be necessary.

There is a great deal of information available online if you Google "making propane forges".

[m_brothers]

Here's a nice photo of a sweet stand, that I'm gonna do with my gasser.

http://www.fredlyfx.com/others/Dave%...20finished.jpg

[bipolarandy]

quite a few regs on that forge... i wonder what thats about?

[Jymm Hoffman]

take a look at my response to this thread in blacksmithing: coal vs gas