Forge Help

[cstark]

Hello All,

I'm new to blacksmithing but I'm trying to learn, slow process I've come to realize! I went and built myself a wood burning forge out of an old 55gal drum and some pipe. Basically I cut from the top rib of the barrel up and flipped it so the solid bottom was against the solid top. Welded them together and cut out a square for me to put the metal I'll be working on. Put some concrete along the inside and a funnel of concrete towards the middle. I also have a basic air set-up, a T of pipe leading to the bottom of the fire box where the air is sent and a "drain" cap where I empty the ash that falls down, and I have an air compressor hooked up with a valve which lets me control the air flow. And my anvil is a 12in piece of train track that I cut out a horn and shined it up.

I haven't had much success, which I expected, trial and error at the moment... My main issues at the moment are I can get my metal hot enough to manage but I can usually only get about 20 seconds (rough estimate) of time to do anything with it. The piece I'm working on right now is 1/4" thick which I know the thinner it is the faster it cools but do I need to get it hotter? It gets light yellow at times. 

Also, with a wood forge, should I have a thick, thick layer of coals on the bottom? I never thought about it but my metal is usually pretty close to where my air is fed, I'm assuming that isn't a good thing. Forgive the questions, I'm just very interested in this and could use some help. Any advice would be appreciated. Thanks!

[jjhend28]

My experience isn't with wood forges, and I have very little coal forge experience.  So my 2 cents would be to post some pictures of what you have built. and make sure you get one with the fire going.  It just helps to see what you have going on vs. reading what you have. 

[ThomasPowers]

Lets see you shouldn't use concrete in the hot zone of a forge; clay from a local creek is better!   Air compressors are much worse for blowing a forge than a cheap blow dryer and a possibly free exhaust assist fan from an HVAC company's bone pile would be better than either.  For a charcoal forge you need low pressure air; using a compressor is like driving a dump truck to the store---sure it works but it's an expensive way to go. Please describe how the air gets into the forge?  Tuyere/grate/side blast/?

Preheating your anvil and tools till they are warm to the touch will help extend working time as will hitting at a fast rate!  As you have noticed 1/4" stock cools quickly.  Is it mild?  If so you can hammer it down till black; A36 possibly and high carbon NO!

[cstark]

Thanks guys, I'll post pics after work today. I've got a pipe coming out the side that connects to the T and my air compressor hooks into that. And I can take out the concrete if it's a bad idea, figured it would be better than nothing to protect the barrel itself. Maybe line it with firebrick then fill with the clay? I don't know if I'll be able to get enough clay for the job... And how the air gets to the fire box is I have a metal cap on the pipe that has small holes drilled through so the air can get out to the fire. Like I said I'll post pictures with and without fire. 

As far as metal and grades of metal go I'm not certain. I started with an old shop file I had that never gets used and that turned out to be brittle when I tried to fold it (I was practicing techniques rather than trying to make something), so I went to the hardware store and just bought a 1/4" x 46" piece of hot-rolled steel. I have to go back today anyway so I can see if there are any more specs on the steel. I also got an old leaf spring yesterday, are those good to work with? 

So would a hand-crank blower be ideal? Or what is the best? I'm not opposed to spending money on this project, it's a fun hobby that I would like to turn into a skill.

Thanks, much appreciated!

[Michael Cochran]

Wood fired forges are workable but you really have to let some wood burn to coals to fill the firepot area. One draw back is you're gonna have to be constantly feeding more wood into it. I have used wood a few times and when I do I have the air turned way down to a very gentle breeze otherwise the air cools the metal. When I run wood I use a bathroom exhaust fan that isn't connected to the pipe on the forge, I leave a good air gap around it to let extra blow away. I would suggest buying a bag of lump charcoal. You'll get plenty of heat and it's not nearly as hard on you trying to keep the fire fed and trying to hammer at the same time. 

[gote]

Wood by itself does not get very hot since there is so much volatile matter (including residual moisture) that will suck up much of the heat generated. More air than what is needed to keep the fire going will also take heat away. The high temperature comes when the wood has turned into charcoal. Thomas' and Michael's advice is good. I agree on all points. Figure out how you are going to hit the stock when it is in the fire and then hit as fast as you can without missing. There are smiths that make a show of hitting a thin piece of steel so quickly and hard that it turns red and can lit a fire. I prefer an electric fan rather than a crank since it frees me when the stock is in the fire. It also allows me to keep one piece in the fire when a second is on the anvil. You must be able to regulate the flow. Rheostate, valve, dump valve ...

.

[ThomasPowers]

Charcoal, real charcoal not briquettes, has been used for smithing for over 2000 years, didn't start to use coal to the high to late middle ages so all the viking pattern welded swords were made in charcoal forges. ("Cathedral Forge and Waterwheel"  Gies & Gies) When I use charcoal I tend to build a wood fire in a separate raised firepit downwind of the forge and just shift the hot coals over to the forge---much more pleasant that way.  Might look up the 'Tim Lively washtub forge' for some ideas.

Trying to learn on high carbon steel is not a good idea it's fussy on temperatures, quenching, harder under the hammer, etc and so on.

What you generally get from the rack at the hardware store as  "weldable steel" is A36; also I can generally buy a 20' long piece from a steel supply store for the same price as a 4' long one from a hardware store.

Small holes are not suggested, 1/4" is the SMALLEST I would use.

Hand crank blowers are excellent for charcoal forges; the bigger blowers running slowly are nicer to use than the small one cranked fast to get the same airflow.

Don't know where you are at; but here in America the cheapest NON-CLUMPING cat litter is actually clay and can be used for forge lining after rehydrating---don't employ the cats to do that step!

[Frosty]

Welcome aboard, glad to have you. If you'll put your general location in the header you  might be surprised how many Iforge members live within visiting distance.

You're making a common beginner's mistake looking for "the best". It isn't the tool that does the best work, it's the worker. You just want tools that will work, you can look for what works best for you after you know what you're doing with them.

As Thomas suggests buy your steel from the local steel supply and I suggest you start with 3/8" square or 1/2" round, hot rolled steel. 1/4" cools too quickly especially in contact with an anvil. You only have seconds before 1/4" stock is too cold to work, it's not really good for beginner projects that aren't extremely simple. I only use it for nails, rivets, simple hooks and occasional hangers and racks.

You need to know what you're going to do when you pull the steel out of the fire, NOT lay it on the anvil and think about what to do, the anvil will draw the heat out of your stock very quickly. Have your hammer in your hammer hand when you draw the stock. Do your thinking and planning while its heating.

Frosty The Lucky.

[cstark]

I've attached some pictures of my forge and anvil. You may have to really look at the fire box to see the cap I have holes drilled into (it's a 1" cap). I hook a 17gal air compressor up to the valve on the side and have it open as little as possible unless I'm stoking the fire to get the coals going. That fire isn't what I use to heat my metal, that's when I first lit it to get the coals going. And with the wood I have a huge supply from scrap wood to split firewood. I'm in a family of carpenters and I always have bits from that and I cut firewood for my home. Wood is convenient for me but I am definitely going to try all of my options. 

I actually have a fire pit just a few feet away from the forge and thought about making my coals there and then moving them to the forge but I wasn't sure if it would matter, I'll try it that way as well. 

I'm in Ohio, with the cat litter do I have to filter anything else out of it or just re-hydrate? I'll look into that, interesting idea. 

Also, I read somewhere that with some metals I had to "normalize" I believe the term was? Such as files. Is that necessary for things like leaf springs and track spikes? 

[ThomasPowers]

Normalization is generally used when working higher carbon steels for tool making and blade making.  It's letting the steel cool down in still air from above critical temperature.  When I forge A36 I tend to let it normalize too but by tossing it in a safe place to cool on it's own.  Sometimes A36 will harden if quenched and I only want my steel to harden when I want my steel to harden---I don't like surprises!  Leaf Spring and RR spikes:  Yes for leaf springs after forging and no RR spikes don't profit from it as they are low carbon steel.

Where's the mousehole opposite the entrance so you can heat the middle of a long piece?  If you get the cheapest kitty litter that only lists "clay" as it's contents you are good to go.

I built a "shovel" out of shale shaker screen to transfer coals, I get a big scoop, shake out the ash and smaller bits and dump the good coals in the forge as needed.  With a good supply of wood you may want to look up making your own charcoal from it for the forge.  Got some threads here on it...

[Frosty]

Just dampen bentonite (clay) kitty litter so it squeezes into a lump then ram it into your forge, don't wet it into mud like plaster, it WILL shrink check when it dries like a mud puddle.

You need a proper stand for your anvil, that table has too much flex in it. It would work better sitting on the ground. Screw 4" x 4" together stood on end makes an EXCELLENT anvil stand and you can custom fit it to your anvil's size. Then just forge spikes or use wood screws ad washers to clamp your anvil down.

Frosty The Lucky.

[cstark]

That's a good idea with screen shovel I'll have to try that. When I built this forge all I was planing on doing was small, small stuff like RR spikes but today I got into that leaf spring and I started working on a mouse hole. I think I'm going to make a new forge with a whole new design with the clay lining and a different air set-up. 

I threw the anvil on that stand because I wasn't (still am not) done with the anvil but now that I've started using it I feel it's good enough for now. I'm definitely replacing that stand with a much more solid stand. 

Thank you for the help guys, greatly appreciate it. I believe any other questions I come up with would be in a thread somewhere here