Fondy_Iron

Brake Drum forge build, opinion and guidance needed

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Hi all,

Finally got the time to hit the junkyard and get a few parts for a forge.

Here is the brake drum I am using it is 13" across and about 4-1/2" deep
(post-26699-0-55072200-1353890983_thumb.j)
The back of the brake drum has a large hole about 5" across
(post-26699-0-55527600-1353890987_thumb.j)
The backing is the wheel bearing that I cut down
(post-26699-0-69535700-1353890985_thumb.j)

And here are the pieces as I would be assembling them
(post-26699-0-43530300-1353891007_thumb.j)

My question is this, the hole in the bearing that I can use for the tuyere, is only about 1-1/4" across and I plan on using 2" pipe
for the rest of the construction, is this hole too small? Will reducing the pipe from 2" to 1-1/4" create too much force in the
forge and blow the coal out of the forge?

I do not have a very strong blower, the only thing I could get my hands on (for the moment) was a 2 speed hair dryer that I've
stripped the heating element out of.

Is there another approach to reducing that 5" hole? I figured since I found the wheel bearing that fit I could cut it down and
then weld it in place. But the size of the tuyere has me worried.

Any and all information is welcome


Thanks in advance,

-Jeff

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I've done the hole, it tends to focus the airflow to the center of the coal bed. I made a grate from a piece of plate and cut 3 slits to spread the airflow. It worked much better.

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My forge has a 2-1/4 inch opening and I use a 1/2 inch bolt welded across the opening as a grate / twyere. I burn fines or coal dust and do not have an issue with the opening being too large.

No welder, then bend some round bar to fit into two of the lug bolt holes and cross the opening.

Make a table and cut a hole so you can drop in the drum into the hole and it will catch on the rim. Makes like so much simpler. Look for a piece of 10-12 inch pipe, tube, whatever and cut a mouse hole at the bottom. Stand it up for a chimney with the mouse hole a couple of inches from the edge of the drum.

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When I built mine I used a disc brake rotor in the center. This gave me a 2 in opening into which I placed a piece of exhaust pipe that I flared over the horn of my anvil. This arrangement also covers the lug bolt holes in the brake drum. A piece of 1/4" plate with a bunch of holes drilled in it completed the package.

Daniel

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I used the flange same as pugman, but I cut a piece of sheetmetal that fit flush with a lip that ran around the inside of the drum. I drilled holes in the sheet metal to match the lug bolt holes and bolted it all together, which helps keeps the flange in place. I also punched a series of small holes in the sheet to act as a grate. Generally I'm pretty happy with the set up, but the sheetmetal is a bit light and distorts a fair amount once the forge gets hot. When it comes time to replace it, I'm going to try and find something heavier, like 1/4" plate.

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on my brake drum forge I used two floor flanges one above the hole and one below it to trap the pipe nipple in position.

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Is that a brake drum or brake disc? (Gathering as much info and knowledge as I can while trying to piece together my own.)

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Appears to be a brake rotor (disc) but the main thing is the bowl for the fire pot. What it did before is irrelevant as long as it does what you want in its new life :)

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I was just curious. I'm building one myself and am using a brake rotor from a house trailer. I didn't know if it is too big or shallow or whatnot. I've fired it up in a temporary state balanced on cinder blocks. Will be setting it into a metal table I have as soon as I can. I'll try to post a link to a picture of some of the components including the drum.

Forgebits2.jpg



Forgebits1.jpg


I hope I'm not doing wrong posting this here... should I have started a new thread? I don't want to cause problems by hijacking someone else's thread.

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Here is a picture of the brake drum I am starting with. Its a brake drum off of a 48ft box trailer. I will use a 3/8 plate on the bottom and 2" pipe to build the air intake structure and the ash dump. I will also build a grate to go in the bottom out of 1/2 round bar.
post-29274-0-85934600-1354323008_thumb.j
post-29274-0-34082200-1354323018_thumb.j

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I dont know correct terminology but the depth from the bottome of the cut out section to the base of the drum is about 2". Time I build a 1/2" grate in the bottom it will raise that to approx 1.5" in depth from the bottom of the cut out. I also want to cut a smaller window on the opposite side of the big opening that can stay covered unless I need to pass through something longer to heat in the center of the work piece. Atleast that is the plan.

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I can tell you that 1 1/2 inches of fuel under your workpiece is not enough. However there are many choices to elevate your work in the fire to the 4-6 inch area. Bricks are a personal favorite.

I did rebuild my brake drum forge to get this desired depth so my bricks are now simply fuel containment.

Phil

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Just plain old bricks work well for me also. They eventually crack and break, but they are easy to replace. Firebrick is likely a better option, but use what you have. My firepot is ~4 inches, but with a few bricks I can bump it up to 6-8 inches easily.

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The heavy firebricks cut very nicely with an angle grinder. Makes them easy to fit into the a brakedrum firepot and get another couple of inches of fuel under the iron.

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I just went and checked my brake drum. It has an outer diameter of 13" and an inner diameter of 12". It's only 2 1/2" deep. Using a 2" endcap that rests about 1/2" into the bottom... that would leave only about 1 1/2" of fuel. So... I have a 16" long piece of pipe that has an inner diameter of 13" and is about 3/8-7/16" thick. It slides over the drum, barely. I am thinking of using it to extend my firepit depth to the 4-6" that Phil recommended. Anyone see a flaw in my theory?

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LR, you don't have to go that far.

The principle that Phil was talking about is the distance from your air entering the fire to the piece being worked. This area is often referred to as the 'neutral zone' because this is the area where the oxygen has been burned up the most. If you get your iron too close to the air entrance, it will still get hot, but you'll have excessive scaling. Same as if you had the iron sitting on top of the fire so one side was exposed to the open air.

By getting a 4" thick bed of coals surrounding your work, between the iron and the air, you're giving a bunch of time for the O2 to burn up in the coals. Basically, your workpiece should be in the center of a ball of fire that measures at least 8" in diameter.

What you need to do is get a piece of sheet metal (like the door from an old clothes dryer) and cut a hole in it so that your brake drum sits down in it, catching on the lip of the drum. Maybe the big hole in the center of the deck of an old lawnmower would be the right size.

This gives you a large table that you can build your coal UP on. A big mountain of coal, so to speak. To be honest, I had never considered using a brake drum like you have, and I'm really impressed with how good of a fire pot it looks to be. The conical shape of the inside is very reminiscent of the coke pots being sold by Centaur Forge and others, and the depth doesn't look bad at all. I'll certainly have to keep my eyes open for one!

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Vaughn, thanks for the information. I am definitely taking all info I get in and sifting through to find what works for me. I have a LARGE metal table in the shop I'm gonna drop it into.The inside isn't conical, it is the same depth across, the shape of the outside bottom part is misleading I believe. There are 'fins' that create the taper look from the bearing hub to the drum itself. I had coal piled into it with just a piece of metal with holes drilled in it for a grate fush with the bottom... it got real hot and heated up the metal I stuck in it real quick, or so it seemed to me.

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Instead of building a table for my drum forge,I took an old push mower removed the motor wheels ect. and flipped it. The break drum sits down into it nicely.

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I don't have to build a table. I already have one. I actually set it into the table last night. Now I need to work on a base for my anvil.

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