Howling dog forge

building the Dog box.

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The need of a small-ish 350 in³ single burner that can forge weld,maintain optimum forging temperatures and travel well sets the parameters for this project, lets see what Mr. Murphy can do to discourage me , shall we? 

First, you gotta have a flame.

finished, more or less, two Frosty burners and fired them off. One is as smooth as the xxxxxxxxxxxxxxxxx and the other is a bit ragged. I suspect that the gas tip is slightly out of alignment and I think I can correct that problem. I used Klutch .035 mig tips as they will work in my machine as well, they are only 3/4" long rather than the 1" twecos .IMG_0191.JPG.5f6b3367bc17cff677a5c580a7757812.JPGIMG_0190.JPG.529b27ae23cb59d913d93b6b5ee09456.JPG

I wish I did not have to use quite so many fittings to get what I wanted but if I make the adjustment bolt a bit shorter it won't be quite so extended, a jam nut rather than a regular 1/2-13 will free up some room as well. I can probably take off an inch give or take.  this arrangement makes it pretty easy to tune on the fly                                                                                                             IMG_0186.JPG.da534d108c67b273ffccd143fcdd3ead.JPG

the 3/4" couplings have been internally tapered at 5° and it does seem to have a positive effect on flame. IMG_0187.JPG.2ae468d59903007d26d04c03977496d9.JPG

Tried it from 6 to 15 PSIG with a stable flame throughout. IMG_0182.JPG.a3750e36301fd5ce83fee75935a38007.JPGIMG_0183.JPG.fffee9bd775bef4db7db0883395580d9.JPGIMG_0184.JPG.7fd7eef97ec82f981dc8cbee8f3bc285.JPG

I am surprised at how easy this was, I believe that with all the parts on the bench, even with all the machine time I could build 4 of these in less than an hour and a half. Not I need some malleable couplings that can be welded to the skin for the pyrometer and something suitable size to hold the burner in place, strangely enough not something available at the big box store.

Any critique on the flame geometry? I figure the real proof is in the forge. I am impressed by the amount of heat these things deliver. Wow! 

Now for a box to put one in.

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As for the forge build and the size you want check out the Build a Gas Forge attachment at the Forge Supplies page on my web-site using a Freon tank.  You can probably get a Freon tank for free from your local HVAC company or any auto repair shop that does AC work.  You can get my contact info on my profiles page here.

Let me know if I can help you.

Wayne

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Now for a 350 in ³ box 

start with a hunk of 16 ga. 10" x 48" . Mark from both ends 1", 11",and 19". Make a cut at 19"IMG_0193.JPG.24013f35e62484d8cf7da6758d247bb2.JPG

HF open throat shear is my first choice, quiet and not a lot of sparks and dust. 

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Now to the brake.

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two ,pretty much identical pieces, don't forget to deburr edges they make a very nasty paper cut.

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and if you clamp them together you get a square tube 8" H x 10" W x 10" L. $5 bill for scale.

IMG_0199.JPG.e5dfcf2ffff3efd97101421596956821.JPG

 

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You can see the jet is misaligned in the second pic, probably the cause of the sputter and corrected already. Flames look pretty good from here but won't know for sure till they're in the forge.

Frosty The Lucky.

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that was burner "B" right and left side to show off my screw up as much as possible.  the flame pictures are burner "A". and both will get a little modification when I am in the mood to make chips.

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As long as I am in sheet metal mode I think doors are in order so having one piece of 16 ga 10" x 10" left from the sides and scrounging up another piece put a double 90 that would have been a lot easier in 18 ga. but I think it will work for what I have in mind.  this should conclude the sheet metal portion of our presentation. 

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they will be positioned about like this ,if all goes right. and if not I guess it's back to the drawing board with tail tucked firmly between legs..

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if using 2 1" layers of kaowool.  10"x8"x10" becomes 6"x4"x"10"=240 cubic inch.  probably a little smaller because of kastolite and matrikote. (that is assuming you are following the waynecoe design).

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But if your using a 1" layer of Duraboard LD and 1/2" of Kastolite it is a lot closer to 350 in³. I am thinking I will try a final layer of Zirconium silicate and Bentonite for reflectivity. 

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Yep thats pretty darn close to 350.  Out of curiosity how do you intend to align your burner?  Will you do a straight on flame path or will you angle it in an attempt to get some swirl?  Also how are you attachimg your doors?  Doing a hinge system or some sort of tracking so they are "adjustable" sliding doors?

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I thought I would start with things vertical  dead center striking a kiln shelf, I have a couple thoughts on swirling the flame but I want to see if I get the results I need from this before changing things. Right now I am thinking sliding doors, I think this offers the best option for reflection back into the box at all "open" positions. The mechanics are still on the drawing board . I have made one attempt at this and had so so results. It slid well enough but I decided a solution that did not require a milling machine would be much more elegant.

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Gotcha I ask these questions because I've been looking into building a square Forge myself and was just wondering what you were doing. However one thing I would recommend to you is putting your doors on a vertical slide rather than horizontal so that if you were working with something long you can still get maximum reflection with pass-through

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How do you propose to hold it in position?? Not sure I see an advantage but I shall ponder this further. the only things I can think of that would be a good pass through situation are bar stock and I think that a vertical door may result in me getting burned more often not least is it is a lot easier, I would think some type of counter weight system would be needed to keep it neutral and the door just isn't going to be that heavy.I am not feeling it but please convince me otherwise.

 

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Drill some holes and just use a simple pin to hold it in place not counterweight etc needed.  If you dont do a lot of long work it probably doesnt matter for me it seems every other project is hanging out the back.  By going verticle you could still close off all but a little bit while still keeping your work near the burner flame in the center of the corge over having it jammed up against the side of the forge to still get closure with a horizontal door

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I am hoping that being in the center of the flame is not as important as it has been or has seemed to be in the past but you make valid points. So I am thinking "how about one of each?".  I get a quick open and shut on one end and a diagonal pass through in the burner zone, if so chosen, for long stock. I think this is a very constructive idea, I thank you for your input.:D

Something to add to this is that the "Doors" do not make contact with the shell, they are purely reflective. There will be a 1/2" gap between the door refractory and the shell refractory.   

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You using a naturally-aspirated burner and as such you have to have some exhaust vent so the door is not touching isn't really an issue what I may suggest doing and what I have planned when I built mine was to have the rear door touch so I could fully shut the rear but I intended to have about a half inch gap on the front door to allow 4 exhaust my intention is also to add a 2-inch by 2-inch "viewing window" in the front so that I can still keep an eye on my work when everything is completely shut up

 

Just spit balling ideas and future plans here i see no need to change your set up to this as the gapping is to a degree necesarry for a na burner

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Keep in mind there's a good chance your door will warp due to uneven and repeated heating.  If you have tight tolerances for the tracks you're likely to have problems sliding your door(s) in short order. I visited a smith a few years ago that had a vertical door in some very loose tracks, and he used a counterweight and cable system to keep the door at the desired height.

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46 minutes ago, Irondragon Forge & Clay said:

Another thing to consider about using kiln shelf for the doors. Kiln shelves do not take kindly to the rapid thermal cycling in a forge and they will crack unless heated slowly (ask me how I know).:)

Kiln shelf is for floor in burner zone. Doors are duraboard with kastolite  just like interior walls. right now I am thinking of sliding 1/2" black pipe on 1/2" allthread. pretty sloppy fit. door shell is about 2" away from shell and on the back of refractory will be interesting to see how distorted they become, hopefully minimal.

 

1 hour ago, Buzzkill said:

 I visited a smith a few years ago that had a vertical door in some very loose tracks, and he used a counterweight and cable system to keep the door at the desired height.

I think I could see the counter weight and cable for a forge a bit larger than 300 in³. right now I am thinking a couple of nuts on the allthread to set the opening height.

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I like a nice fly-weighted wingnut - they can remain quite cool in operation:

 

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Robert Taylor

Edited by Anachronist58
Post Assembly

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