Blacksmith's Coal Forge

[Frazer]

Hey folks,

This isn't necessarily hearth related, but it's something I thought some of you guys might find interesting nonetheless.

Disclaimer: In case some future blacksmith stumbles across this thread, I am going to start by saying this is not intended to be a tutorial. Just because my setup is legal in my town does not mean it will be allowed for you. Always consult your AHJ to determine their requirements prior to starting your build.

I closed on a house back in December with the intention of moving my shop into the detached "garage" (more on the scare quotes later). In my naivety, I thought, "I just need a chimney put in, how hard can that be?". :eyeroll: This was my first time moving everything indoors and for safety/insurance purposes I wanted to keep everything above board. At the end of the day, I'm glad I did. That being said, with it being such a unique request in my area it took about 5 months to find a company willing to do the installation, obtain a permit, get parts in and do the installation. Some of that time was due to CV19 related delays, but much of it was spent jumping through hoops with the town.

So, what is a coal forge, in a legal sense? In my town it is an unlisted solid fuel burning appliance. This means I was required to maintain a 36" clearance from the forge and hood/support frame to any combustibles. I fabricated side draft hood as well as the frame the whole stack sits on.

Unfortunately, to save some money, I see quite a few blacksmiths who use single wall and/or galvanized spiral duct for their chimney. For several reasons this is not allowed in residential applications near me. I have however seen 12" spiral used in a local school, but they have a much more involved exhaust system. Not having the code in front of me I can’t quote chapter and verse of NFPA 211 that gives the reasons, but suffice it say it’s not a smart move.

I went back and forth between going through the wall or straight up and out through the roof. I ended up going with a 10” SS DuraTech system going straight up and out. The stack is 14’ tall and to keep the smoke away from the neighbors the top of the cap is 7’ above the peak of the roof. It is quite impressive looking from the road.

I can already hear some of you saying, “You put an exposed coal fire in a garage? But NFPA 211 §13.2.4!”. I agree with you, and I think this is a stumbling block for many who try to install a solid fuel-burning appliance in such a structure. After the code office passed my permit application over to the fire marshal with a shrug of the shoulders not knowing how to handle a forge, I got a call from him. One of the additional requirements for me to be able to proceed with the installation was to submit, in writing, a letter to the town agreeing that, “Neither flammable liquids nor equipment such as vehicles, lawnmowers, weedwhackers, etc. which operate through the burning of fuel in an internal combustion engine are to be stored within the structure at any time while the solid fuel-burning appliance is also present.”. While I was on the phone with the fire marshal, he even said, “Well, I guess we can’t really call it a garage anymore.”. Nice guy. He was very understanding during the whole process. I also had to agree to a couple of other stipulations that they had, but they aren’t worth getting into here.

If anyone is interested, here’s a video of the first fire:

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I’ve been using the forge for about 2 months now and the performance has been excellent. It was certainly worth the investment of time and money. Speaking of money… They must line this pipe with platinum or something, phew! That stuff is expensive! I probably could have done the installation myself, but with the amount I was spending on parts alone, I figured it’s best to let the pro’s handle it.

Anyway, thanks for reading. I'm happy to answer any other questions if you guys have them. I left out some of the details for the sake of brevity.

-Frazer

P.S. No that isn't a filter on the photos. I don't have a smartphone so the image quality is pretty bad.. It doesn't really help that my lens was dirty

P.P.S. Hopefully I posted in the right section. Feel free to move my post if necessary.

 

[clancey]

Did not know anything about "BlackSmithing" or even what a forge was and so I went on u-tube to find out--what an eye opener for me to see--wow--talk about labor--wow....This is a art that is a lost art and these people built our nations.. I watched The Last blacksmith and really enjoyed it...Thanks for the start of knowledge for me in checking out your posting. mrs clancey

 

[SpaceBus]

I'd like to build a forced air charcoal forge myself, but that's a while off since I don't even have a workshop!

 

[begreen]

What sort of work will you be creating?
Looks like some heavy metal there. Cue Black Sabbath.

 

[stoveliker]

Good for you doing everything right and legal!
Cool looking coal fire!

 

[Frazer]

Mrs Clancy, YouTube is a great thing, there are actually quite a few of us out there and the community seems to be growing. Most of the blacksmiths I have met are all great folks. I little dusty and of the "no-nonsense" variety, but good people overall.

Spacebus, psh, who needs a shop, my first setup was a weber grill lid, flipped upside-down, some black iron pipe, a hairdryer and an improvised anvil (piece of steel I found at the scrapyard). I think I got myself setup for $20-$30. It was a little (okay maybe a lot) janky, but it at least it was outside and let me decide whether this was something I wanted to pursue or not. Knowing what I know now I probably could have started for even less than that. It's taken me years to acquire all the toys -- *ahem*-- I mean tools I have now. You really don't need much to get started, but a little training goes a long way. Charcoal is nice, quite a few people use it very successfully, but IMHO the stuff you tend to find nowadays isn't fully pyrolyzed .. Lets off a lot of sparks (fire-fleas) if you give it too much air. If you can find it, bituminous coal or coke is the way to go. Just don't buy the expensive stuff online. I get 50# bags at $10/bag, fortunately coal is pretty cheap.

begreen, you'll have to pardon the photo dump... These are just a few things I've made somewhat recently; I don't mean to take up unnecessary bandwidth. What I make really depends on what I need or am asked to make. Generally speaking, I make a lot of tools. I always say, "if it's made of steel and of reasonable size/dimensions, I'll try to make it". I'd apologize for the mess in the shop, but an organized workspace is a sign of a lack of creativity... That's my story anyway and I'm sticking to it! I was raised on Ozzy Osborne, Randy Rhoads was one of the all-time greats. However, my all time favorite band is tool. A tongue and cheek comment, but apt nonetheless.

Stoveliker, IMO if you play with fire as a hobby , you might as well play with fire legally!

 

[SpaceBus]

I don't like the toxic ash and smoke that comes off of coal, but otherwise I see the appeal. Traditional Japanese blacksmiths used softwood charcoal and were able to forge weld. Living in a softwood forest it seems very appealing. When I catch up on some other projects perhaps I'll give it a try. I need a hobby that's not developing infrastructure for our tiny farm The last month I've been looking into a modest stick welder I can run off my portable generator. I've got some expired 20lb propane tanks that would be a perfect candidate to be cut up and welded into a charcoal retort and a charcoal forge. My plan is to try and make a retort that fits into my Solostove Yukon smokeless firepit and then the smoke associated with making charcoal can be burned with the wood gases from the fire pit fuel wood.

 

[Frazer]

I hear you there, coal can be a messy business and it isn't for everyone. I don't mean to speak ill of charcoal, it's a perfectly viable fuel source and has been used a lot longer than coal has. Many people use gas forges as well. Naturally, each have their pros and cons.

Wait, you have a farm but no welder?? *gasp* How do you fuse the spurving bearings on your encabulator's reciprocating dingle arm without an inverse capacitive current concentration box?!? ...I'm not crazy.. someone out there will get it.

It's funny,.. It seems the more I weld, the better I get at grinding. *grin*

That sounds like a nice setup. I've never made charcoal myself, but I'm all about using what you have available.

 

[SpaceBus]

I hear you there, coal can be a messy business and it isn't for everyone. I don't mean to speak ill of charcoal, it's a perfectly viable fuel source and has been used a lot longer than coal has. Many people use gas forges as well. Naturally, each have their pros and cons.

Wait, you have a farm but no welder?? *gasp* How do you fuse the spurving bearings on your encabulator's reciprocating dingle arm without an inverse capacitive current concentration box?!? ...I'm not crazy.. someone out there will get it.

It's funny,.. It seems the more I weld, the better I get at grinding. *grin*

That sounds like a nice setup. I've never made charcoal myself, but I'm all about using what you have available.

I see you are also knowledgeable about turbo encabulators. So far I haven't had any equipment failures, but this is only my second season with livestock and third with the tractor/equipment. I haven't welded anything in several years, and I wasn't the best at it to begin with.


Gas forges definitely seem convenient and probably the easiest for someone like me with no experience. Coal definitely gets a lot hotter than charcoal, so there are definite advantages.

 

[begreen]

Very cool work Frazer. Thanks for sharing. You are a talented man.

 

[peakbagger]

I missed out by a generation, my grandfather was killed in an industrial accident in 1921. He had a home forge and his brother was a black smith for a pulp and paper mill. When he retired he had his own shop for about 20 years. I worked in three places that had blacksmith shops but the blacksmiths had retired and they never replaced them. One place had an electric induction forge that they still used on occasion. Just turn it on with the right size induction coil, slide the piece of steel into the coil and it turned red quickly. They still had a coal forge but the crew claimed the old smith used the induction rig most of the time. I dont hear much about electric forges but my guess is it needs a pretty hefty power feed.

 

[Frazer]

Spacebus, under the right conditions gas, coal and charcoal can all get hot enough to melt steel. While coal does burn the hottest of the three, a fire really only needs to be so hot. If a forge is able to reach and maintain a welding temperature then that is all you really need. I think the most common downsides associated with each fuel are:
Gas: Can be tricky to tune, you are limited to what will fit in the forge, slightly longer heating times
Charcoal: Rapid fuel consumption
Coal: Dirty, dusty, often smokey

begreen, thank you. I started a little over 3 years ago and, while I have come a long way, I still consider myself to be a novice in the grand scheme of things. So far the whole learning process would make for an interesting case study of the Dunning-Kruger effect.

Peakbagger, for what it's worth I'm sorry to hear about your grandfather. Blacksmith shops used to be just about everywhere and luckily many of the tools from that time period (and before) are still around today. My anvil was cast in 1920 in Stockholm, Sweden and is still considered young as far as blacksmith's tools go. I have seen a few people with induction rigs and they like them. I think 15kw is pretty standard for household unit. Certainly not that much power compared to the commercial units, but 240V @ 60A is still nothing to sneeze at. I've never used one, but the people that do say that they have their place , but switching over entirely would be difficult.