I finally got my new forge running and I was rather disappointed in it. Before I go back to the drawing board, I was hoping that you fine folks might offer some simple tweaks that might improve performance.

In an effort to avoid confrontation with my local home owner's association (hopefully, I can start making presents for them soon, but first things first), I decided to use charcoal. This is available to me year round and is not too expensive for the amount of forging that I do. I constructed a small forge out of a discarded lawnmower body and am using an adobe-filled bucket with a one inch pipe passing through it for a fire pot. The pipe has two 1/8" holes drilled in it. I constructed a small, double-chambered bellows (about 18" in diameter) which has a 1/2" pipe nipple protruding from it. This is attached to the tuyere pipe via a piece of 3/4" flexible water heater conduit.

I have never really used charcoal before (I have always used coal) and am unfamiliar with its nuances. When lighting the fire, I put a lit piece of newspaper over the tuyere and got it going like the flame coming out of a blow torch (in terms of sound), but It took a long time and a LOT of pumping to get the fire hot. I put a piece of 3/8" rebar in to the fire and it seemed to take a long time to get hot. Additionally, I couldn't get the steel above orange heat (although it was hard to judge in the light). I was using natural lump charcoal, not briquettes, by the way.

Does anyone see any obvious tweaks here?

I would also like to add that the shop has no power (or I would have used a hair dryer) and I have limited tooling (my arc welder is in storage and I have nothing to plug it in to).

Thanks,
Rob

My impression is that there is not enough air. You need bigger pipes to deliver the air.

Yes, larger and more holes in your air grate and a full sized bellows or at least twice as large as you made. The air output of a bellows is exponential compared to it's size, one twice as large puts out 4x the air so shrinking them means you get to the "why bother" point quickly.

Frosty

So it can't be saved?

Rob

Hook up a shop vac for the time being while you build larger bellows. Make your air delivery system larger and have fun.
Finnr

Hi Rob
i'm sure i've seen antique commercially manufactured 'portable' forges with 18 inch diameter bellows. I think they had a 1 inch air outlet all the way, even try a couple of sizes bigger. Old catalogues such as linked recently on the forum often have specifications eg;
http://www.iforgeiron.com/forum/f7/old-belgian-blacksmith-catalog-12213/?highlight=belgian

good luck, i had the same problem matching tuyere size to a large blower i had to use.

Andrew.

If I understand your description right the the air gets to the fire through two 1/8 inch holes. If so, I don't expect you are getting enough air through those holes. Increase both the number and size and try again.

ron

The key to a forge fire is volume of air, not air velocity, smaller holes will restrict volume (and increase velocity) which is not a good thing. Also the bellows do sound small. Over the last 3 weeks I built a pair of great bellows myself, and just the air chamber (without measuring the front 'cone' part is 48 inches long by 32 inches wide (overall length around 5 foot 3 inches long)

I feed my tuyere through a 3 inch flex hose. I have an electric blower with plenty of capacity and had to use a speed control on the motor, plus I have a shutoff damper. Into the bottom of the fire box I cut two slots about 3/8" wide and 2 1/2" long. That allows all the air I need until the clinkers build up.

Jmercier, that is a great looking bellows. What size is your pipe at the end of the cone?

That's a 2 inch pipe

Rob,

I would change the nipple out of your bellows to at least 1.5" and get some more holes in the tuyere. Mine is actually a grate made form 3/8 rebar welded so it has a 3/8 space between the bars.

Air is the answer and it sounds like you are short on it.

Good luck.