Well, I've suffered a bit from workus interruptus the last two days so I haven't made the progress on the forge that I wanted to. Tomorrow will be more of the same, I'm afraid, as a last-minute job came in and I have to do that because I get to roast them on the fee.

I did workout the solution to holding the doors snug against the shell at all opening height.  I'll make four gravity-operated pressure rollers  that will hold the door frame against the track it rides on, but will allow it to be pulled away a fraction of an inch to move it up or down easily.

This is not the simplest forge I've ever made by any stretch of the imagination.  It's actually quite involved but it will be extremely versatile and comfortable to use, so I think all the work will be worth it. I'm also trying to work out everything well enough to eventually sell plans for the forge.

To answer a couple of questions you guys have raised:

Having the burners in the floor does present the possibility of debris getting into them, but a buddy of mine has a forge set up this way and he has cranked out a couple of thousand hammer heads using it with no problems. As I noted earlier, I also put a couple of ports in the shell so I can easily change if I need to.  Belt and suspenders theory of design, y'know?

I have always been able to get my gas forges to attain a welding heat.  I can usually get them to attain a heat that will melt cast iron and burn up high carbon steel, too.   The heat a forge will produce is primarily a function of the number of Btu's dumped into it and the size of the chamber.  There are a number of other factors as well, but these are the primary ones.  Many people make forges that are too big for single burner they install so they can't develop enough heat.  Another thing is that many people have their burners running way too lean - that's just extra cold air you're putting into the forge.  To see if this is the case in your forge, try closing off he intake air a bit and/or closing down the opening of the forge until the burner is almost suffering.  

Gimperfi, those forges that Ken Scharabok makes are fine little units for the money.  If you want to get more heat out of one, add another layer of Kaowool inside.  Less volume plus lower heat loss equals higher heat.  Forge welding wire is always a pain in the rear.  Too much surface area for the volume of metal and too little volume of metal to hold the heat long enough to weld.  The trick on that is to get a chunk of red-hard steel like H13 or D2 that will just fit inside your forge and heat it to a red heat and set it next to the forge door - this will be your welding "anvil."  Now heat your work as hot as you can get it and go quickly to your pre-heated anvil to stick the weld.  You'll be able to get as much as fifteen seconds of working heat this way.  Using a room temp anvil that is three feet from the forge means the work will be too cool by the time you get there and the cold anvil will suck the heat from the work on the first blow.

For really small pieces I use a pair of short-jawed tongs and just reach into the forge and pinch the weld together in the fire.  That gets it "stuck" and I can then go to the anvil and work it down a bit without too many problems.  Easier still is to just TIG it together and then forge out the weld.  That one never fails.  :-)

More to come...

Rich

Great info Rich! People have forged welded in my forge at my yearly I.B.A. meetings that I have every year, but not me. :) I just "Jump Weld" as my buddy Charlie calls it. (I jump over to the TIG and weld it. :) :)
But your suggestion of the little heated anvil makes GREAT common sense!!! That's a great tip. Now I want to try that! :)
This thread has prompted me to do what I have been wanting to for some time: post pix of some of the tools I've made in hopes some of you can get some ideas for yourselves. I want to contribute in some way and a couple things I've made turned out to be pretty handy.
My forge "shell" is something you might take a look at. I used 3/4' #9 stainless expanded metal and Kaowool. (It may not need to be stainless but I have it.) I form the shell to the size I want with the x-metal. I stack two pieces of wool together- 4" and 5" wide by the length of the forge - and fold the strips in half and in the crease I stick a piece of hardware that is a 1/4" rod with 1/4" bolts welded perpendicular to it. I then stick the bolts thru the kaowool and fold them over the rod. The bolts then stick thru the x-metal shell and you put a nut on the outside. Make sure the kaowool will be about 2" thick when installed. The hardware is also protected that way and will never burn up.
I hope you understand my jibberish as I am no great literary figure. But if you think about what it looks like when you are done, on the inside of the forge, it can be likened to the edges of the pages of a book or layers.
I show people when they come in the studio and see it glowing yellow inside that I can turn a piece of mild steel into a sparkler and yet put my finger on the wool on the outside of the forge thru the x-metal and not get burnt. (It's amazing stuff, isn't it!) Just BE SURE to NEVER touch any metal or near the openings. I also use ITC 100.
Also, having fire brick around the base of the shell allows me to slide one out of the way in case my scroll or piece I am working on requires it. I can also lift the whole shell up as well.
You have some interesting ideas with what you are doing and I am looking forward to seeing what it looks like.
Thank you for all your help and suggestions!!! Hope I didn't impose on your thread too much.

Much appreciative,
Chaz

No fear on the thread hijack, Chaz - I put this stuff out here to share information with everyone and more information is a good thing. I understand what you're doing with the Kaowool on the roof of the forge - I've done a similar thing myself by accordion folding the Kaowool and then "sewing" the folds together with a piece of inconel wire. (Interesting, the spell checker didn't recognize "inconel" and suggested I might have actually wanted "incontinent" - not!) Pleating the wool actually seems to make the forge more efficient as it increases the surface area which in turn increases radiant heat.

For this iteration of the forge I'm gong with two layers of 1" Kaowool laid in flat on the arch. When it is time to replace it I'll probably try another idea I have in my head, another way to increase radiant area by as much as 80%. That will be a whole 'nother project, though! :-)

One thing I'm doing differently on this forge than any others I've built previously is making the "foundation" (base, shell, doors, etc) with the intent that they will be relatively permanent items and only the linings will be sacrificial. In the past I've always figured that when it was time to reline would just whip up a new forge entirely, but this design is pretty damn labor intensive so I hope it will be a long-term investment. If it works out as planned, it will definitely be worth all the work. If, however, it doesn't work as planned, I'll probably stick my head in the oven. (grin)

I sent the bulk of today doing paying work and only managed to steal a couple hours for the forge project. I got the plenum for the air curtain fabbed up and installed and settled on a blower mounting method and location. Tomorrow is more paying work for half the day and the rest on the forge. Once again, I forgot to bring the camera over from the shop, so pictures are still a day or two away.

Rich

Cool Rich. Thanx for the info. (Good choice on the spell check!! LOLOL I didn't know this site had it. Can you tell? :) )
Looking forward to your pix. If you get a chance to look at my other thread on tools, there is a place where I have pix of my forge posted. I "think" I did what you are talking about making the base fairly permanent on a rolling cart with a steel floor, layer of wool, and then fire brick. The brick right under the flame is starting to erode a little but not a concern yet. I have used it for about 7-8 years, altho not continously, quite a bit. I even use it to anneal copper AND to heat my studio! :) Mine uses 10# pressure nature gas.
I did not realize that about the surface area and pleating the wool. I just know it is a great way to hold the wool and not burn up the hardware. The stainless x-metal shell obviously holds up good as well. It does get a little burnt at the openings but it's still all there. I did not get real elaborate with my doors, on the front,just two pieces of fire brick that slide on the floor of the forge with a 3/8" s.s. rod along the top to hold them up. So far so good!
On the back, one piece of fire brick that lifts up and down and hold in place with a bar that goes from side to side and has bolts thru it and into "couple nuts" that are welded to the forge body. (probably clear as mud, I know :) :) LOL)

Thanx again for all yor info! Lookin forward to pix!!
Chaz

Hi Rich, I'm qurious if you have ever posted pictures of your shop? Having read your post for awhile now I would love to see what it looks like. How a man keeps his shop is a window into his soul. I have also learned alot from reading your post. Thanks for sharing your knowledge.
Gimperfi

GImperfi,

Hmmmm....I don't think I have posted any pictures of my shop, now that you mention it. I'll see if I can rectify that in the next couple of days. I'm sure I have some in one of my demo folders.

Rich

Hi Rich, the forge looks great and really user friendly. If you ever decide to draw up plans I will definitely buy a set. I have a few questions, first, does the removable side panel just rest in place? Second, what are the gray L shaped brackets with the rollers that are directly behind the vertical tubes for? Third, can you post more picts/info on the air curtain and the idle shift? Both of those ideas might be something I can do the forge i have now.

This really makes me want to build a new forge.

jake

Jake Balcom
Mettle Design
Lincoln, NE

Jake,

The air curtain is just a blower of any sort hooked up to a plenum below the forge table. That plenum is necked down to a narrow slot the width of the front opening and about 3/16" wide - i.e., a narrow slot that turn the air into a thin curtain of moving air. I use a fan control to regulate the speed, though it could be as well done with a choke plate on the blower intake. Dead simple and really effective at diverting the dragon's breath up and away.

The L-brackets and rollers on the doors are pressure devices to keep the door snug against the front of the forge body in all positions. The L-brackets are counterweighted to pull down, and the "L" configuration changes the direction of force to horizontal to push the roller against the back side of the square tube guide the door rides against. There's probably a better way to do this, but I made those doors really heavy (20# each) because I didn't want them to rust out, so I needed some way to hold them shut that didn't interfere with sliding them up and down. This was my solution, I should think you could come up with a more elegant one. Or make the doors from thinner sheet and Kaowool board instead of 1/8" plate and firebricks.

The removable side panel simply rests on the forge base, and is connected to a rod-in-tube arrangement to allow me to pull it open and then swing it down out of the way. The firebrick liner for it is held to it with both stove cement and a couple of stainless steel bolts. Easy to replace if I crack it somehow.

The sides of the forge body are likewise firebrick for the first three inches up from the floor. These, with a heavy coating of Plistix 900F, are much more durable than Kaowool when getting jabbed with iron repeatedly. Again, they are held to the body shell with stove cement and stainless bolts for easy replacement.

Hope this clears up those questions for you, and feel free to ask any others you have. I'll be working on a set of "plans" in the future. When/if I get them complete I'll let you know. I don't want to finalize them until I've had a chance to use the forge for a few months to determine if I need to modify anything.

Rich

Gerald,

Glad to hear you're inspired, and I hope you get busy on it and make improvements while you're at it.  Here's some pictures of the bottom, as well a sI could get them with everything in my way.  :-)Forge PlumbingForge Plumbing 2

Plumbing 3

Hopefully this will be useful.  The stainless steel canister thing is my punching lube and swings in or out as needed.  The plenum for the air curtain has a clean-out plug on the bottom, since I'm sure it will eventually fill with scale.  The rest you can figure out, I'm sure.  If not, ask away.

Rich 

I'm willing to bet that if you put your mind to it you can not only copy the t hing, but improve on it. I've noticed over the decades that no matter how much they protest, most blacksmiths can improve almost anything if they want to. I always hope that whatever I post someone will improve on it and then I can swipe their improvements for myself. (grin)

Rich

Thats a really nice forge ....in the days when I used coke for my ovens we had similar lifting doors and sides ...the only problem was that we had to keep a hose nearby because the blast of heat was too great when working with large blocks of steel and we would need to cool ourselves down whilst moving to the hammers ....
Just a thought ... all the industrial forges had a pipe running in front of the doors with a row of holes for air ...the good thing about these was that you could rotate the pipe to change the air direction and force the heat back and up ...mind you, they were powerfull fans because they also provided the blast for an oil furnace...
thanks for all your details, I hope it works well for you
Giusseppe

Giuseppe,

The pipe with the holes is a good idea for a way to do the air curtain - I like the notion of being able to adjust the angle. I just used a slot outlet on the plenum and placed it where it would cut off the dragon's breath. Would definitely be nice to have it adjustable, though. Ah well, there's always something to improve on and I'll make a mental note of that suggestion for the next iteration. Thanks!

No matter how well the air curtain works, when you haul out a 20+ pound piece of steel at a high yellow heat that thing is going to try to roast the front of you! I've made a couple of thin stainless steel sheet metal shields that can be secured to the tongs with a hose clamp to shield my hand and arm from the worst of it and they really help. I do the same thing when chasing or chiseling sometimes, if the piece is radiating uncomfortable amounts of heat.

Rich