welding with charcoal

[connor bachmann]

Hey everybody. My coal supply has run out until the winter and, at least for now, I'm back to using charcoal. I don't remember how i used to forge weld with charcoal. I used to be able to, and now I can't get anything above an orange heat (which is also problematic when working with wrought iron). I'm wondering if anybody knows if i need to use a certain type, what air blast to use, insulation, etc. Help would be very much appreciated

[Marksnagel]

Hey Connor,
What type of charcoal are you using now? If you are using briquets, there are a lot of impurities in them. Lump charcoal will work better for you and you will definately have to experiment with your air supply since the change from coal to charcoal requires some changes to be made. Since Your forge type is unknown any answers would only be a guess. If you can post a picture of your forge and its air supply I'm sure that someone here will be able to guide you on the right path.

Good luck!

Mark <º))><

[pkrankow]

I will assume that you have good lump charcoal.

You need a deeper fire than coal, and much less air than coal.

Phil

[connor bachmann]

ok. yes i'm using lump charcoal, homemade in fact. I'm not sure about direct or indirect charcoal though.

my forge is a bottom blast with a shallow firepot. it's made from an old grill. the air source is a hairdryer. I tried using that, then i tried using a brick construction with a hand pumped mattress inflator. then with a hairdryer again. neither are getting a welding heat. I'm using charcoal produced through the direct method, should i attempt to use charcoal produced with the indirect method?

[evfreek]

ok. yes i'm using lump charcoal, homemade in fact. I'm not sure about direct or indirect charcoal though.

my forge is a bottom blast with a shallow firepot. it's made from an old grill. the air source is a hairdryer. I tried using that, then i tried using a brick construction with a hand pumped mattress inflator. then with a hairdryer again. neither are getting a welding heat. I'm using charcoal produced through the direct method, should i attempt to use charcoal produced with the indirect method?

The most common problem with forge welding when using charcoal is an oxidizing fire, often caused by an insufficiently deep bed. Other problems are bad charcoal. I once saw a smith at a demo reject all the charcoal because of unsuitability for welding. The conference organizers had to sell it as BBQ charcoal at a loss. He explained in detail how the ash from some hardwood charcoal contaminates the weld.

If the forge is not getting hot enough, you just need to make sure that the pieces are small enough, the bed is deep enough, and there is enough air. A hair dryer is usually sufficient, if the holes in your grate are large enough. Also, chop the charcoal to walnut or smaller size. Provide some pics, or even better, videos with sound.

[Frosty]

You can build the depth of the firepot by putting bricks around it. In general deeper fire, careful blast is the secret. Hardwood charcoal last longer but softwood charcoal makes a hotter fire. This is absolute temp terms the actual BTUs/lb may be equivalent.

Breaking the lumps into fairly small pieces, say walnut +/- increases the surface area and helps use all the oxy in the blast so deeper and smaller lumps helps. Once you remember the tricks welding with charcoal is actually easier than coal.

Frosty the Lucky.

[ThomasPowers]

Charcoal forges generally need a narrower and taller forge pot. Ge a ruler out and look at what a 6-8" pile of charcoal should look like.

Charcoal needs "softer" air than a coal forge---ie you don't need as strong a blast and a strong blast will actually be worse than a slow one!

For a smallish forge the charcoal should be fairly small too---say 1" cubes; I usually put the big stuff on top and when it's burning tapping it with the forge rake makes it subdivide.

As coal was not used for smithing until the high middle ages all the viking swords were forge welded in charcoal fires and traditionally made japanese swords are forged in charcoal fired forges to this day. It can be done!