Forge building-rough cost?suggestions?

Matt Shade

Matt Shade

Joined
Nov 24, 1999
Messages
4,981
Hey Guys
I'm thinking of building a forge. Main use will be for heat treating at this point in time, so I'd like to make one with pretty good capacity. And then somewhere down the line I'll probably start hammerin some stuff too.

Right now I kind of have an idea, but don't know what it will cost to get it running, or if its even a good one.

I have an old comercial grade propane tank (about the size you use on most grills, but its much heavier steel) that I want to use as the body of the forge. Right now, I'm thinkin cut a hole in the top and bottom of the tank and weld a 3" or so diameter steel pipe through it. Then cut a hole in the top big enough to back fill the tank with refractory around the pipe. Then its just a matter of putting a burner in one end, and maybe a door to control how much its vented. The tank already has a frame around the bottom to hold it up off the floor, and I'll probably weld some legs up so I could sit it horizontally too.
The guy that shoes my horses said that he's made burners before and would show them to me, or I may just buy one depending on how much they cost.
So what do you think? good idea? bad idea?
Whats it going to cost getting the basic hardware together (hoses, regulator, fittings etc.) Can anyone give me a ballpark figure on that?
I'm not real worried on the most efficient gas use or anything like that since this is mainly for heat treat and I probably won't make more than 20-30 knives a year for awhile. It just has to get hot, I'd like to be able to hit about 2000 deg if possible since I'm using the oil quench method on 440C, along with working with O1.

So I'd appreciate any advice before I get in over my head :D
 
Alrighty
Sorry for pretty much duplicating Burchtree's thread. I read it, and alot of my questions were answered(hadn't seen it before I posted this one).

I'd still like to know what you experienced folks think of my initial design idea though.
I've thought about it a little more, and figure on keeping the pipe through the middle surrounded by refractory, but maybe extending it out on the end with the burner and putting a Y on it so I could add a second burner, or blower if necessary.


Also, anyone have a good idea for getting that first hole in the tank? It hasn't been filled in years because its a commercial tank (stamped with Ohio Bell) so they won't fill it for anyone thats not authorized by Ohio Bell (which was bought out by Ameritech, which was bought up by SBC.....) so it should be empty, and I plan on letting it sit outside with the valve all the way open for a few days.
My dad said to drill a small hole in it with a hose running on the bit. I was thinking I'd rather be 100 yards away though. So I need suggestions on caliber....do I try my .22 with stinger solids, my .54 muzzle loader, or call up my buddy with his .270 :confused: ;)

Thanks
 
Matt, 2 questions/observations:

You plan on putting the refractory around the 3" pipe? I've read about forge bodies turning molten when refractory was put around the metal "can", how about lining the empty bottle with refractory?

Just from a safety standpoint wouldn't it be better to get a freon tank or piece of scrap pipe from a junkyard instead of a propane tank. :eek:

Will
 
i vote for the 270, everything else will probably just bounce off :D of course maybe even the 270 may unless you have a solid pointy tip. :footinmou
 
Good idea Matt but a couple of things concern me.

First, you will find that the burner should angle into the side rather than the end. It takes a little piddleing to get the right placement but you will find it.

Second and this is a big one.Do not add a door . On a gas forge it is very dangerous. Sure people do it. I've done it. I've done a lot of things. That's one of the reasons that I came close to checking out last year. I disregarded a lot of safety advice. Remember, that gas forge is a bomb waiting to be created. I wouldn't worry about a real explosion, but a serious gas flash can and will burn you and worse, may blind you. Ain't gonna make many white cane swords.
There are a lot of sites that have a wealth of knowledge about forges. This has been discussed dozens of times here so a little searching will give you plenty to work with.

Third.....if you intend to use the propane tank, pull the valve and fill it all the way to the top with water. Make your first cut and then just empty enough to keep the saw dry.

A better suggestion is to get a freon can. Most heat/AC people will find one for you!

Good luck!
 
hmmm
Hadn't thought of the pipe inside melting, guess I just need to weld it on one end to to mount stuff on, and then use a cardboard tube or something to form the refractory.

I could hunt up a peice of pipe, or a freon tank or somethin, but this one has been sittin in the shop for years. If I use it I save myself two trips cause I don't have to take it to a hazardous waste drop off and I don't have to go find something else.
Shooting it isn't a problem, its a short trip to the middle of nowhere :D I don't think a .270 will bounce off, they're notorious for smoking those pendulum targets they make for .22's. I don't think my .54 plains rifle would bounce off either, I just think it would cave in the side of the tank :o

Thanks guys :D
 
Looks like we were typing at the same time Peter
Thanks for the tip on the door. The guy that shoes my horses has a commercial built forge that has a large swinging door that makes up one side of the box, with vents/openings on the end to put longer stuff in, thats where I got the idea.
I guess I'll have to think over using this tank, if everyone thinks its that bad of an idea.

I'll look for some other forge plans to see about the burner. With my heat shrink torch and firebrick set up I've had much much better luck with vertical L and the torch blowing in the from the side/bottom, so I figured I would want it blowing straight through. Now that you mention it, all the forges I've seen do have the burner on the side though, hmmm.
 
The idea of putting the burner in from the side and an upward angle is to create a vortex. The inside of the forge should be almost as hot as the flame itself. The mini tornado of hot air just helps this along.

PS...Matt, I didn't say it was a bad idea, I just want you to go about it safely. There are plenty of chances to hurt yourself in this business/hobby without thumbing your nose at Mr. Murphy!
 
Originally posted by peter nap
PS...Matt, I didn't say it was a bad idea, I just want you to go about it safely. There are plenty of chances to hurt yourself in this business/hobby without thumbing your nose at Mr. Murphy!
Click to expand...

And I appreciate that. I am very good at hurting myself with everyday things, so when I take on a project like this I need to hear every warning several times before I start :D
 
Matt,

This worked for me with my old 20# propane tank:

I took the empty (mostly empty, it ran a grill 'til it went out) tank and a garden hose and a cordless drill with a 1/4" bit in it about 50' down the driveway - a relatively clear area. Cracked open the valve and there was a short whoosh, then nothing. Opened the valve all the way and filled that sucker with water, drained it, and repeated a few times. Warning: the residue (oily stuff) in the bottom of the tank STINKS - my driveway smelled like a gas leak for days afterwards. Filled the tank one last time, closed the valve, and laid it on its side (to avoid any chance of an air/gas bubble on the bottom). Drilled a single hole through the bottom into the water. Got the drill splashed a little, not too bad - it was less than 20 volts anyway (cordless, remember). Stood the tank back up and let water run through it (taped the hose into the valve) for about a half hour, until the water running away from it on the ground no longer had that oily rainbow sheen on it.
Here's where it got difficult - I was going to unscrew and remove the valve - no way!! Open end wrench on that thing, beat it like crazy, eventually tried the BIG channellocks, but it wouldn't let go no matter what. I wasn't ready to torch or cut the thing out, so I inverted the tank and stuck it out behind the garage, where it still sits. I'm sure by now it's perfectly safe to cut it open as it's been sitting a few months with the valve open and the hole in the bottom - plus a few more extra holes I added later to the area that will be eventually cut out.

I believe this was about the safest way to do it, but I'm not positive. However, I'm still here and alive ;)

Eventually it's going to end up being a cross between Ron Reil's mini-freon tank forge and Indian George's air-blowing beast. Pics of both are on their websites.
 
Thanks
I didn't realize the valve on these things would open up enough to run a hose into them. I'm really not worried about cutting the tank at all now.
Worst case scenario once its been opened up and rinsed good is a little residue left inside flashes. No big explosions or anything. I'll probably do similar to what you did to initially get a hole in it, then hook a grill snap starter up to a length of wire and see if I can't purposely burn off any residue while standing at a safe distance in a safe area :)
 
Two things come to mind here...

1) the addition of some detergent or surfactant like "grease-cutting" dishsoap should help get rid of oily residue

2) dunno exactly what that oily residue is, but trying to burn it out may not be a great idea--if it is volatile you'd be igniting an air/flammable mixture in a confined space. That could generate more excitement than planned.
 
You probably have found it but since I didn't see it posted above here is Ron Reil's website.

I built the "EZ Burner" and used a freon tank someone gave me. I spent something like $150 all together but I had to buy a propane tank and everything. Didn't have squat. :)

I strongly recommend you think a long time about what Peter said about setting your burner so that it creates a vortex inside the forge. I put my burner in at an angle, but it shoots right against the opposite side of the forge so doesn't create the swirl you want to equalize the temp inside.

So now I have a "hotspot" that I have to move the blade through to ensure I get an even heat going. That would be okay for forging but for heat treating you sure want the most even heat you can produce.

You need to set it so the flame comes into the forge at an oblique angle to the "wall". I haven't yet figured out how to do that without welding, so haven't built the next one. Eventually I'll get to it though and weld the mount at the proper angle. You can save yourself some heartache by doing it "right" the first time. :D

Anyway, that's my 2c worth. Good luck and have fun. There's nothing like building your own stuff, is there? :cool:
 
Thanks for the info
I understand about the vortex thing a little better now, the forge I had seen with the burner coming in at a right angle was for horseshoeing and the guy throws the shoes right into the hot spot. That definitely isn't what I want for heat treating though. Probably have to add a 45 degree elbow into the burner design somewhere so it will hit the pipe wall at an angle and make the swirl inside.

I'm going to have to get together a parts list for a few of the different burners on those pages and then head into the welding supply store downtown and see what I can get together. I may just order a premade burner from somebody too (guy that shoes my horses might already have one I could buy) and then I can go straight to figuring out what angle to mount it at and what I need to weld up for it all.
 
Matt,

You can see pictures of mine in the other post. But I have bar stock welded next to the entry hole. The burner is held in place with a simple hose clamp around the burner and bar stock. Then I just bent the bar to adjust the angle the flame enters forge. Nothing more than that.

To do it again I think I'd have the burner hole on the side and angle up. But I do get a pretty good swurl where it is.

Steve

PS, A friend made the shell for me. He'll make you one if you want. Email me.
 
Thanks
I think I'm pretty well set now. Tonight, I ran some water on the valve and then opened it, no hissing or bubbling.
So then I ran more water on it and took the valve apart, it hissed/bubbled a little around the threads and I just stood back and waited for it to quit. (should mention I was out in the open)Then took it clear out. Now its sitting outside with a strong mix of white lightning degreaser concentrate and water in it, clear full.
Tommorrow I'll drain it and then refill it with water and drill a hole in it so I can fill and drain it easier to rinse it good before I start cutting.

One question. How do you attack Kaowool? I'll probably use a mix between it and firebricks to line this thing.
 
You must log in or register to reply here.
Back
Top