Forge Pics...in progress...at last!!

Kalindras

Kalindras

Joined
Aug 24, 1999
Messages
933
Well, after plotting and scheming and looking for bits and parts for a year, I'm finally almost done with my gas forge!! It's never gonna win any beauty contests...definitely nothing on the quality of Ron Reill's stuff, but if it heats steel and doesn't put me out of house and home in gas, I'm happy!!

Here she is (her shell, at least):

forge01.jpg


For the lining, I used the Homemade castable refractory, mixing Perlite and Furnace Cement (the recipe is here ). His proportions are a little off, though I had problems with some of my cement being dried out, so they were wonky for me, anyway. The stuff is an unholy mess to mix (much like playing in the mud as a child, though), but easy enough to pour when it's done:

forge04.jpg


I used the caulkable type to seal around the edges, and around the firebrick shelf. While pouring, I used a plastic cup to make a conical opening for the burner (okay, I'm cheating...I ordered a T-Rex from Rex Price, rather than blow myself up :rolleyes: ). I think it approximates the 12-degree cone fairly nicely:

forge03.jpg


Finally, in places where there were air pockets, the Perlite texture came out...I'm gonna try leaving it, but if it becomes an issue (anyone have any predictions?) that's costing me BTUs, then I'll break down, buy some more cement and smooth the insides up:

forge02.jpg


Finally, before I even THINK about calling this puppy complete, I'm trying to head off some possible issues without having to reinvent the wheel:

1) If I block up the back with firebrick, is it going to be necessary to close up the front, to prevent heat loss? The whole forge is 12" d., with the inside being roughly 8" d., to allow for some non-knife 'smithing.

2) If I block up the front, how much would be enough of an opening, to prevent the dreaded back-pressure that will prevent my venturi burner from working well? Any thoughts?

3) Are there any glaring boo-boos you see that I've missed (besides not having a burner mount, yet--I'm still working on finding one)?

Thanks to everyone who has helped, and will help, to get me beating steel!!!

:D ;) :D

Kal
 
This is GREAT info and too much for me to digest on a Friday night. I was thinking about making a forge and this seems to be the ticket. Thank YOU for helping me out.
 
I like it. It reminds me of my first one that I made. I had too much blower and could melt cast iron. I made alot of damascus in it but it is now retired. Mine took a long time to get to welding heat and used alot of propane. I think yours should work better. I think you should build a back door on it but have a slit in the back door if you want to heat treat a sword. It will hold the heat in and you can turn down the propane after it reaches temperature. I also think a front door or front bricks on the sides to also help the heat stay in. I dont think you will restrict the air flow enough to lose the venturi effect. Have fun with it. Tell us how it works
 
Kal, that's great, it's going to change your life. You'll be making damascus next week! Thanks for the refactory recipe too, I'll try that on my next one.

Dave
 
Another good reason for the doors is that you can close them for anealling the steel when you are done forging. It takes several hours to cool off. Works good.
 
Great info, Bruce! Hey, I was also wondering...I pick up some Durablanket, this weekend, and was going to use it to construct a back wall-plug that I could put in or take out as necessary...would this be any better or worse than just blocking it up with firebrick?

Thanks!

Kal
 
1) If I block up the back with firebrick, is it going to be necessary to close up the front, to prevent heat loss? The whole forge is 12" d., with the inside being roughly 8" d., to allow for some non-knife 'smithing.

2) If I block up the front, how much would be enough of an opening, to prevent the dreaded back-pressure that will prevent my venturi burner from working well? Any thoughts?

3) Are there any glaring boo-boos you see that I've missed (besides not having a burner mount, yet--I'm still working on finding one)?

I agree with Bruce, block off the back but either leave a slit or do as I did and use Firebrick to allow swords.

Some of the burners are funny. I built one that a little wind would create enough backpressure to be a problem. I also have one that nothing causes it to flicker. I got fed up and built one with a blower. I use a Kao-wool blanket to cover the front. It keeps the heat in but allows pressure to vent. Hold your breath when using it though.
 
The advantage of the firebrick back is they can be moved or opened up for venting and forging long billets. They should be set into a mild steel channel so they can be slid apart or closed. Mine were just stacked against the back and would get pushed off sometimes when I forged long blades. Have you ever tried picking up a 2000 deg. brick? Ouch! The front side bricks could be adjustable too. Forging is more fun with a well made forge.
Bruce B
 
Anyone ever use the high temp cement and bricks available at hardware stores for fireplaces? Do you think this stuff would work?


Randy
 
I use a Kao-wool blanket to cover the front. It keeps the heat in but allows pressure to vent. Hold your breath when using it though.
Click to expand...

Ah, I was wondering how you'd learned to forge a 12" Bowie in one heat!!! :D

Seriously, though, I'm hip. I hear this stuff does nasty things to your lungs. I plan to 'seal' it with thinned-down furnace cement, to keep the outer layer of fibre from flying away. Would this have any effect on the insulating qualities, do you know?

Kal
 
The only suggestion I have is to angle the burner toward the front slightly. If the forge doesn't act like you want it to, play with the orifice size. I have used refrac coating over kaowool. it doesn't seem to affect it. I just took the kaowool out of my little forge and lined it with mizzou from RHI ind. Wish I had left the kaowool in and refracted over it.
I was looking at heat treat ovens and their deluxe model is built that way.Refrac over kaowool.

The old forge had a 3" hole in the back, I just use loose bricks, but may close the back up with more refrac.

I used a 1-1/2 of refrac and it is not enough, heats good, but I'm loosing heat through the shell.
 
I just finished up this one, to do welding in. It got up to welding heat pretty fast and uses a lot less gas then my 2 burner verturi forge. Get that forge done and get to hammering and have fun.

Bill
 
Bill,

On your Don Fogg forge, how is the burner, blower, etc, affixed? More pics would be great. It looks like a slick one...

JD
 
Just got email from Rex...my burner's ready!!!

For anyone in the area, here's a listing of places where I've gotten bits or work done:

Mobley Pipe (pipe for shell)
972.245.7473
Ask for Don Chapman, he runs the place, and is a knife collector!!!

D&S Tool (Having a flat ground onto my RR Track Anvil)
972.241.5263
Talk to Charles or Curtis, very affordable machining done here.

Turner Hardware (a plethora of gidgets and fittings, furnace cement)

Harbor Freight (Acytelene Regulator, other parts)

Northwest Propane (Propane, Tank, Hoses)
Harry Hines, between Royal and Forest on the West side.

Home Depot (Perlite and assorted bits)

And, of course, Rex Price (T-Rex Burner)
Home of the T-Rex!!

All of these suppliers, in addition to all of the great folks here on the 'Forums, have really helped me get this together. Another GREAT resource has been the NTBA (North Texas Blacksmith's Assoc.). All of the guys, and especially Ron Hardy, have been EXTREMELY helpful in coming up with those head-slappingly obvious solutions to problems that were blocking me for days, weeks, or months.


Once I get all of the final pieces together, and fire this puppy up, I'll get some more pics and let you know how it's working!!!

THANKS!!

Kal

:D :cool: :D
 
Nice setup Bill. I'd love to see a drawing showing how you have your jet fixed and what kind of jet you are using.
 
I don't mean to take over Kals thread, but his forge is horizontal and mine is vertical, so its really good for both I would think. This way you will have an idea for which ever you might want to build.

this vertical is made from a 20" x 12" diameter steel pipe, its walls are 1/2" thick, and I know it doesn't need to be, but this is all I could find. The door holes are 2 1/2" x 3" and the burner hole is 1 5/8". I put 2 -1" layers of kaowool in the bottom, sides and top, and the bottom has a 1 " fire brick cut to fit laid on top of the kaowoll to protect it from flux.
The burner is , starting from the tip, a 45 degree 1" street elbow(black pipe), the 45 shoots the fuel in side ways to give it a vortex affect. from the street 45 is a 6"x 1" black pipe nipple that threads into a 1" to 1 1/2" bushing and that threads into a 1 1/2" to 2" bushing and on to the elbow, from the elbow to the gate valve is a
2" x 6" nipple. then from the gate valve is a 2" plastic thread in coupling, from the 2" coupling a street 90 is glued and a stool flange is sanded to fit the 90 and then also glued, then I just drilled the stool flange to bolt on the blower.
The gas line, I drilled and tapped the 2" nipple to accept a 1/8" brass nipple, used a brass bushing to hook up the nipple to a shut off valve, and put a needle valve in line to hook up the 1/4" ID rubber gas hose. ( Note, get a needle valve made for propane, the water needle valves won't hold up, the propane will eat up the neoprene washer) from the needle valve I have an adjustable regulator on a 100# propane bottle.
The blower is 160 cfm and it appears to be just the right size. If you attempt to build one like this, be careful and do it at your own risk, all I can say is it works for me.
I was welding 1 1/8" cable with it today, with only 1 pound of pressure reading on the regulator and the needle valve was almost closed, so yes you do need the needle valve.
You might have better success with different sized street elbows that go inside the forge, but this appears to be just right for what I wanted. Heres a few pictures to give you a better idea.
 
shut off and needle valve from here the hose hooks to a adjustable regulator at the propane tank
 
one last pic to show the burner hanger, theres a lot of ways you can do this but I like this so I can remove it to light and then put it in place, and when I'm finished with the forge at the end of the day I can turn the gas off at the tank and remove the burner so the heat from the forge doesn't migrate up the burner to my blower. Just make sure not to make to big of a hole in the forge side so the burner end will be held in place,and the burner will be held tight by its own weight.
 
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