Total Newb looking for advice

[kiltedpiper]

Greetings all,

I am an upstart red/blacksmith and I am working putting together a masonry forge. I'm going to have a brake drum made from cast iron as my firepot. My plan is to set said firepot into concrete or at the very least make it removeable for later.

My main question on this is as follows. since the bottom of the brake drum is about 1/4" thick, will I need to weld on a plate to the bottom of it to reinforce the metal? I do not wish to have it melt while I'm using either coal or coke in the process.

Any constructive advice would be appreciated. (I know, I know...brake drum forges are the spawn of khaos but it was what I could afford)

[The Jeff]

Maybe not to constructive, but theres a good bit of info in the  Forges section.

[George N. M.]

Welcome aboard from 7500' in SE Wyoming.  Glad to have you.

I'm sure that you are aware of the drawbacks of brake drum forges regarding depth and difficulty in using longer work pieces and how to mitigate that issue.  However, your statement about setting it in concrete gave me pause for two reasons. One, eventually the metal of the firepot will erode and it will need to be replaced.  It may be years down the road but if it is "glued" down to the concrete it will be a very serious hassle to replace.  Two, and maybe this partially mitigates my first concern, will the heat transmitted through the brake drum degrade the concrete behind it to the point that it breaks down structurally?  You might want to back it up with something more heat resistant like fire brick.

"By hammer and hand all arts do stand."

[arkie]

Cast iron brake drum forges are not all that bad.  Mine has been used continuously for ten years now and shows no signs of degrading.  Just don't dump water on it while hot or it WILL crack.  Also, welding steel to cast iron may be tricky; cast iron takes a certain amount of care and technique to weld.  I would recommend bolting any reinforcement to the bottom if needed.  Bolts can rust, but are easily replaced.  Drum placement in concrete is not what I would want to do as George pointed out.  Mine is just sitting in a hole in 1/4" plate.  The weight of all the air plumbing + the drum keeps it in position.  Brake drums are OK for coal, but charcoal needs a deeper firepot.

[kiltedpiper]

Ok, thank you for the information, I'll keep that in mind.

My plan is to make it so that brake drum can be removed. I plan to set the brake drum on top of a steel plate set in the masonry. On top of said masonry will be a 12" ID IPS steel pipe that surrounds the brake drum. To fill in the space between will be either sand or perlite to back against the heat. This will at least make it easier to replace. I am using CAD to design it. When I am done I will post the PDF files of the forge as well as a tempering furnace. Essentially I was thinking to use a batch box rocket furnace to make that work.

Look up batchrocket.eu to see what you think.

[Frosty]

Disk rotors make excellent fire pots and you can just drop them in place through a hole in the forge table. The disk rests on the table and you can build the table up with rammed clay sand mix for a hard table. Weld a piece of pipe you can make up to your blower hose to a round piece of steel plate that will drop into the rotor hub. It blocks the bolt holes and you're good to go. Make sense?

You can do the same for a brake drum but you run into the too depth problem. You'll just need to cut the table top so the drum rests on the rim flange. Making up to the air and blocking the lug holes is exactly the same. Reduce the depth of the drum by ramming clay sand mix between the drum's bolt flange and the plate used to make up to the hose to the blower. 

Bend 3/8" or so round bar so it lays across the blower port in the plate and you're ready to forge. These air grate bars are wear items so make plenty, replace them as they burn up. 

If you must weld to a brake drum grind it clean and smooth, preheat to 300-350 f and use 7018. No need for cast iron or nickel rod! I've foud welding to the machined hub or rotor plate is easiest.

Frosty The Lucky.