While I have had good luck heating sheet metal (for forging bowls) with a rosebud tip on my oxypropane torch, it is rather a fuel hog, plus I’m paying for the O2.  However, my regular gas forge doesn’t accommodate bowls very well until they’re practically finished. This problem didn’t seem to have a great solution, but then I ran across Eric Thing’s article on Anvilfire about his armor forge. (IFI doesn't allow links to AF, but a websearch for "Eric Thing" and "forge" will get you there.) 

So, here’s my version, with some modifications. First, I replaced the burner with a 1/2” Frosty T- burner powering a 12-hole NARB. Second, instead of Eric’s threaded rod height adjustment, I mounted the forge on a tilting arm, which itself pivots on a support that can be adjusted vertically. Here it is fully assembled:

As you can see, it’s mounted on the back of my gas forge cart. However, it can be removed if I need to run long pieces through the tunnel forge. 

I also made the shell by welding up an octagonal taper rather than Eric’s original frustum of a cone, mostly to make more efficient use of my sheet metal stock. 

This was lined with two 1” layers of rigidized ceramic wool:

And then given a layer of kastolite-30 (not shown). I molded the top with a plastic container that originally held Parmesan cheese, so that it would match the taper of the burner block (see below).

 Here’s the arm welded onto the back of the forge, along with a diagonal brace:

Here’s another Parmesan container set up with the crayons for the burner block. These were first set in holes drilled in the bottom of the container, but then I melted some more wax around their bases to hold them more securely.

Getting the kastolite between the crayons was a bit of a pain, but I managed to ram some in with an icing spatula and a popsicle stick. Then I inserted the plenum (made from the cutout from the mouth of the forge with a 90 degree elbow welded on) and packed some more kastolite around it.

After curing, I melted the extra wax off the bottom with a plumber’s torch and reamed most of the wax out of the holes with a heated piece of thick wire:

Here’s the block removed from its mold, showing the taper from the Parmesan container:

Which fits neatly in the tapered top opening of the forge:

The base of the forge (what Eric calls the "deck") is a 2-1/2” deep octagonal tray, with the bottom lined with a 1” layer (and a few extra chunks) of rigidized ceramic wool:

The finished base can be seen in the picture below of the tilting mechanism. 

(Not shown are two solid blocks I cast in another Parmesan container and a yoghurt container, to support bowls under the forge.)

 Here’s the burner fired up. Lots of calcite and crayon wax burning out:

 First firing of the forge (note the water vapor cooking out of the top):

 And here’s the tilting mechanism:

Even though the refractory isn’t fully fired, it still got a scrap of 16 gauge mild steel up to a respectable glow:

After the first firing, I brought the parts back into the house to cure in the basement some more, where they’ll be warmer than out in the garage. I’ll do another firing tomorrow. 

So far, so good!

Pretty neat forge John. 

Unless I'm mistaken the octagonal prism is hollow. If so it's a natural for hanging a single light bulb in to keep warm so you don't have to pack it in the house every night till it's cured. It wouldn't take much wattage as small and well insulated as it is, 20watt night light or old school Christmas light would be plenty.

Frosty The Lucky.

With the temperatures dropping into the 30s, I don’t think the lightbulb would be enough. The good news is that it’s pretty easy to move: the diagonal brace makes a natural carrying handle. 

Super cool forge. I take it that you make a lot of bowls but that would be handy for a lot of shapes. 

It was originally designed for forging armor, but yes, I make a fair number of bowls. Most of these are yarn bowls for my wife’s yarn shop. 

 

Addendum: one significant difference between Eric's forge and mine is that his deck is at the end of an arm, which allows the smith to get further into a deeply hollowed form like a helmet:

(Apologies for the low-resolution photo; this was a screen grab from someone else's video of their forge.)

I have some ideas for this, should it become an issue in my own forging. We shall see.

 

Update: I decided to go ahead and make such an arm to hold a block of refractory. So, here’s the whole process of setting the entire rig up for forging. 

Here’s the empty cart, showing the mounting bracket:

Here’s the vertical support set in the brackets and pinned at medium height:

Here’s the bottom deck set in place:

Here’s the arm and its pin set in the vertical support, but not yet at working height:

The forge is set in place and pinned:

The arm is brought to the top position and pinned in place:

The forge is tilted up and the refractory block is set in its bracket on the end of the arm:

When the arm is in its top position (as here), the top of the block is about level with the opening of the forge, holding the workpiece in place:

The arm can also be set slightly lower:

Allowing more clearance around the workpiece:

And here’s the entire setup.

The only thing remaining is to upgrade the fuel supply from a single hose (with a basic regulator and running from a single tank, as shown here) to dual hoses, each with its own proper regulator, piped into a braided metal fuel hose. I have all the pieces for this already assembled; I just need to make a mounting bracket to hold the Y-junction in place. 

Addendum: ended up just wiring it to the frame of the cart:

 

That's quite a forge John, how do you like it?

Frosty The Lucky.

Haven’t had a chance to forge with it yet, what with making (and eating!) Thanksgiving dinner. The next couple of days are going to be really busy in the yarn shop, but I’m hoping to fire it up on Sunday.

I hear you, after making and eating thanksgiving dinner all I was up to was a nap.

Frosty The Lucky.

Thank you for the additional pics/explanation as I was unfamiliar with how you intended to use it. Will certainly look forward to your assessment once you've used it for a bit.

One thought that came to mind: a cartoon image from the 50/60s of the salon hairdryers... You'd have a real hothead on your hands!

--Larry

With an opening of about 4", they'd be a real pinhead as well!

A thought: it occurs to me that it would be reasonably easy to add a foot pedal to the tilt mechanism, to make it easier to put the workpieces into the forge and take them back out again. More to think about.

Update: I’ve finally put this to use forging bowls, and it has worked fairly well (once I figured out that the reason the burning wasn’t working was because of the mud dauber nests inside…). 

The support arm wasn’t holding the bowls very securely:

So I moved the whole assembly down a bit. The workpieces are now supported both by the arm and the bottom deck:

I’ve been having some issues with the burner popping, which I suspect may be the result of heated gases feeding back into the air intake after escaping around the edge of the forge:

So I added a bit of sheet metal as a guard, which hopefully will improve things. 

More to come…

(One other thing: the Kastolite I used for both the forge and the ribbon blower was past its use-by date and has been slowly crumbling away. I’ll probably need to replace that sooner or later.)

What configruation did you use as a flame retention nozzle on its burner? One of the many things I like about Frosty "T" burners is how well they work with a variety of nozzle designs.

Yet, I have also noticed reluctance to experiment this way, in spite of the great success a few have enjoyed with them. I suspect that a multi-flame nozzle on the end of your burner would greatly enhance that  forge--just a thought.

I've never gotten satisfactory results from an elbow instead of a flare, even 3/4" x 1" didn't work well. A 45 works well but not as well as a simple thread protector.

If this were up for a vote mine would be for introducing the burner nozzle tangentially at the top of the refractory cone at a slight down angle. It would extend the time in the burner cone for complete combustion and eliminate back pressure. Other than maybe melting the liner out of it there wouldn't be a limit to the size T inducer you used.

Kind of makes me wish I were still paying around with burners, I think this is a near perfect use for a multi-nozzle Ring burner. Make the pipe ring slightly larger dia. than the bowl blanks with the nozzlettes directed towards the center of the disk from vertical. 

Hang the T induction engine straight down screwed into a an inverted acute tubing V that joins the plenum ring and then to the outlets. Might have to figure a way to keep exhaust gasses from choking the T but that's just a tweak if the ring burner itself works.

Frosty The Lucky.