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I have only used a coal forge that I built from a porch patio and it has served me very well. From a family friend, I got a literal mound of coal that has lasted me nearly a decade mostly because of intermittent use up to about 2 years ago when I got more serious about forging. Now I'm on my last two buckets of coal and would like to build a propane tank forge. 

 

I have searched through the forum and this is what I came up with. I have some questions on how much of each material I should buy. 

 

  1. I would like the option of welding in this forge and it seems from others that have this burner that 2 of them makes this easier. What do you think? 1 or 2?
  2. What length of Kaowool should I get? Is there a cheaper supplier that you know of?

     

    Black Beauty Burner --- 2x  ~$96.95

    Kast-O-Lite --- High Temp Tools, 20 lb, ~$64.35

    (From Wayne Coe's gas forge build, it took about 15lb to coat the forge with a thicker bottom layer. I think 20lb should give me some left over for repairs and mess ups)

    Plistix --- 1 pint from Wayne Coe  ~$15.00 + shipping

    Kaowool --- High Temp Tools, ~4ft of 1" x 24", ~$38.00

     

    Total ~= $250

    This seems a bit much but this is my first gas rodeo.

     

    Basic Build Progression

    1. Cut front hole probably 4"w x 3"h and cut front lid off to put kaowool in.
      1. Is that front opening big enough for the backpressure?
      2. To put the lid back on without a welder, tabs and sheet screws in the lid and body.
    2. Cut back hole ~2.5"w x 2"h
    3. Drill holes for burner. Align the holes so that the burners are tangent to the top of the inside walls.
    4. Size 1" for 2 layers Kaowool and insert. Cut hole for the burner.
    5. Mix up the KastOLite to spec and layer it in with the bottom thicker.
    6. Cover with plastic wrap and wait to cure. Once its close, dry it out with a heatlamp.
    7. Layer of Plistix.
    8. Slowly fire up the forge with the burners.

     

    Thoughts?

     

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    What you are talking about are venturi burners, or naturally aspirated burners.  There is another option.  If you have not read through this thread, you should.  I have built 50 odd of these and they all will weld with a single burner.  If you have questions about these, please ask me.

    Geoff

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    I found it better to drill the hole for the burner after placing the kaowool lining so by looking into the forge mouth I could better see where it was supposed to go. Remember to allow another half inch or so for the KastOLite.

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    A single black beauty burner is probably plenty for a 20lb propane tank forge, and it will be much easier on gas use.  I currently run 2 of them in a forge made from an old forklift propane tank which is several inches longer than a 20lb tank.  It welds well, but is definitely a gas hog. My last forge had a single homemade burner in a 20lb tank shell, and it welded fine.

     

    Listen to Geoff's advice above.  I don't have electricity in my forging shed, so I can't use a blown burner, but I really wish I could.

     

    I've also found what Charles said to be very true.

     

     

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    Thanks guys. I think I'm going to stick to the black beauty burner, buying the piping and the blower will cost more and I'm on a little bit of a budget right now. I think I will be making a vertical forge at some point that is dedicated to welding and use a blown burner then.

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    Just wondering if I missed something important or if someone might know of a better deal somewhere else before I order everything.

     

    Bill of Materials

    • Black Beauty Burner + shipping  ---  $64.50
    • Plistix (w/o shipping, Wayne Coe) --- $15.00
    • Kast-O-Lite, 20lb (HighTempTools)  ---  $64.35
    • 30 psi regulator + pressure gauge + 5ft hose(HighTempTools)  ---  $55.50
    • 5ft Kaowool + shipping from HighTempTools  ---  $36.00 + $35.43

    Total = ~$270

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    1 hour ago, Mike Ward said:

    I think I will be making a vertical forge at some point that is dedicated to welding and use a blown burner then.

    Mike,

     

    I run into this a lot.  From my point of view (  I have a power hammer and a press in my shop), a vertical forge is what I use for  "everyday" forging and a horizontal forge is what I use for welding.  I make 6-8 inch tall billets, which means that at some point I have to cut the billet into pieces to be able to get it into the press and still reach the controls.  So I want a forge that will heat 16-18 inches at a time.

     

    Most of the rest of the time (forging blades, even long blades) I only want to heat the 3-5 inches that I can forge in that heat, which is why I use a vertical forge for that work.  I have forged a 30 inch blade in that forge.

     

    Now heat treating (normalizing and stuff) I want a long fire box.  That is why I have 4 (5 if you count the electric HT oven) forges.  No one forge will do everything as efficiently as purpose built forges.

     

    This is just my .02 and YMMV

     

    Geoff

     

    BTW,

     

    I believe that you could build the burner I showed in the thread for not much more than the cost of BB.  The cost is in the fan, and you can source the parts locally, so no shipping.

     

    g

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    I respect Geoff's opinion a lot (he gave me pointers on how to build my forge and other stuff). But, For some reason I prefer to weld in a vertical and forge in a horizontal. Mainly because without a handle welded onto whatever it is you are forging in a vertical you have to hold the billet with tongs. Also, my vertical forge just gets hotter and heats more evenly. On top of that, the flux falls to the forge floor that I cast out of Mizzou. And a horizontal forge I have a longer heated area for heat treating big blades, and can cut one burner off to get a hot spot for small blades. I can sit lots of stock in it for mass production of scrolls and stuff too. 

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    21 minutes ago, Zeb Camper said:

    Mainly because without a handle welded onto whatever it is you are forging in a vertical you have to hold the billet with tongs.

     

    Good point. I don't have a welder so a vertical would be annoying.

     

    And honestly I don't really anticipate doing alot of welding maybe just a wrapped hatchet or san mai here and there, not higher layer damascus. I don't have a press or power hammer to help me. As for blade sizes, I'm not planning on doing anything larger than 10" max.

     

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    I do it exactly the same as Geoff. Small vertical forge for 95% of forging with damascus/welding being done in a horizontal. I always felt like most people do it backwards. That short 4-5" heat is really nice. It's really not ideal to keep heating up steel you're not going to be hammering on.

     

    As far as having to have a handle, yes that is true to an extent. A lot of time we're using a long piece of steel already so you don't need anything. If your vertical forge is small enough, then you can lay your piece on the shelves on either side or across the opening without tongs. If you do need to use tongs, it helps to have good tongs for whatever you're doing. In any case, I don't find it to be much of an issue. Once I've cut the forged blade off the bar, most of the time I leave the tongs on the piece just out of convenience. I can usually get by without tongs at all though (except to snag it out of the forge). I very rarely weld a handle on unless it is a small piece that's not a knife. In fact, the only time I've welded a handle on to a knife is when I was starting with a bearing or other large chunk of steel. Of course, you would do that with a horizontal as well, most likely.

     

    I think the only thing that would be better than a horizontal forge for welding (because you really do want a good 16" heated up all at one time for making damascus) is what Ed Caffrey did. He basically took the shell for a horizontal forge and cut it in half (top to bottom if you have it standing up). This way you can weld in extensions, just flat pieces of steel on either side, to essentially create an elongated horizontal forge. This way you have an oval forge that doesn't have quite as large of an interior chamber as some massive 16" round vertical forge but you still get the benefits of a vertical and the length of a horizontal.

     

    I'm also a big proponent of blown burners.

    Edited by Cody Killgore
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    Check out the Build a Gas Forge and the Ribbon Burner attachments on the Forge Supplies page at www.WayneCoeArtistBlacksmith.com.

    Let me know if I can help you.

    If you can't weld it you can use 1/4 20 nuts and bolts for the hinges and can cut and bend the burner holder and attach it with nuts and bolts.

    Do a google search for "Frosty's T burner. much cheaper , easy to build and a good burner.

    Let me know if I can help you.

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    So, I have to ask, why are you guys heating up 16" of Damascus? For the initial weld, or drawing out? I've always just welded up a 4" long billet real tall, popped it in the vertical, set the weld, and drew it out. Maybe it would be better to weld up the 16" bar if you had no press or hammer, but it seems like to me a safer bet to focus on welding 4" and then drawing it out. My vertical will get about 8" up to welding heat. 

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    My press will take 14" at full open.  I have welded an 8" x 1.5" x 6" stack and drawn it out.  When it gets around 24", I have to cut it off because I can't reach the controls.  A billet that big will get to be 7 or 8 feet long, too much to work.  So yes, drawing it out makes an 18" forge convenient.  I also set the first weld in that forge.

     

    I don't think there is a "right" way, it's just the way I work.

     

    Geoff 

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    For me, the length is just to keep heating up the whole billet as it is drawn out. I will use a press or rolling mill to work on the entire billet each heat. Once it gets to about 16”, it’s time to cut and stack for me.

     

    I start with a billet only 6” long or so but also about 5” tall.

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    I’m going to stick to a horizontal forge because the interior is only going to be about 8” long. That’ll help with heat treating longer pieces more evenly. And I definitely am not going to be welding 14-18” pieces, only enough for 1 maybe 2 blades.

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    Another solution to not being able to weld a piece of rebar to your billet to handle it with is to leave one of the middle pieces in the stack a bit on the long side.  You can grip that with you tongs and heat the stack.  You won't have to worry about popping the rebar off due to heating the weld in the forge.

     

    Doug

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    I now have all the material apart from some plumbing. As shown, the most of the kaowool is cut and put in for sizing. Before I go further, what size front and back holes should I cut out? I stayed with a Venturi burner and know that they need good venting to prevent to much back pressure, but am unsure how big or the area needed.
     


     

    D3B0FBD9-F396-4F08-BB95-819229103F9D.jpeg

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    I think the consensus view on the internet (insofar as such a thing is possible) is 7 times the burner port area as the minimum for the combined openings. In most cases, the need to have an opening big enough to get the workpiece in and out will mean that the area of the openings comfortably exceeds this.

     

    Taking a worst-case scenario with a 3/4" burner: the thinnest wall, largest inside-diameter pipe anyone is likely to use is Schedule 5, which has 1.050" OD and .065" wall thickness for an ID of 0.92" and an area of 0.66 sq in. Multiply by 7 to get 4.7 sq in. A 2 1/2" x 2" opening will be enough, even with a 5/8" rebar handle in it. 

     

    From the photo, it looks like the front hole you already have may be big enough, even if you close up the back hole when doing short stuff, and I'm guessing it'll need to be enlarged for workpiece access anyway?

     

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    Is this the right consistency for the kastolite? I can clump together and bounce it in my hand a couple of times before it breaks. I was careful to add only a bit of water at a time, but it seems like it’s clumpy almost in small particles.
     

    83793BAD-5877-4BD7-B0FC-7AE091D849D5.jpeg
    0A6CC08C-5515-4F41-ACFD-BA5DB79ED0F9.jpeg

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    It works!! I left the refractory to cure in a bag with a wet towel for 2 days then let it dry for another. I hooked everything up, checked for leaks, and fired it up. Ran a few short cycles to get rid of any left over moisture and then let’er rip.

    5 psi seems to be a good spot to continuously run it at and ~3 psi is where the burner starts to stutter.


    This is one of the first lower heats.
    898E21B5-8F35-424D-82EE-C2D1CFF0275F.jpeg

    And this is after running it for ~15 minutes. The flame outside is tinged slightly with blue also. Does that mean that it’s not burning all the propane in the tank?


    Also, I forged a knife to test it out and there’s not a lot of scale.

    04EDD495-094E-4164-8362-3F13D56A2804.jpeg


    All in all, I am happy with my first gas forge. I already have plans on how I would make a similar one that would be easier to make.

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    Flame color is going to be wonky for a while, as the castable will burn off different chemicals during extended curing.  See where you are after a good week of firing before making major changes to your burner.

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    I would stuff a bit more wool around the burner on the outside as well. If you don't see yourself pulling the burner out, cover the wool with the kastolite as well. You don't want to run the risk of overheating the burner tube. I don't see it actually melting, but why take the chance?

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    I would not only seal the outside of the forge where the burner tube enters, I would seal the inside as well and use some of the Kast-O-Lite to do it so that something of a nozzle is formed around the pipe or the flame will slowly burn the end of  pipe off.  On one of my older forges I started out with a piece of 12" black pipe that eventually burned down to 6" before I replaced it.

     

    Doug

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    • 2 weeks later...

    SERIOUS, HELP!

     

    Is there any reason why on a new 40 lb tank that the pressure gauge randomly drops to zero and won’t supply gas?

     

    I’ve been using a different 20 lb tank just fine but once I switched tanks it sputters then losses pressure. All lines and fittings are leak free and tight. The openings of the forge are clear. And the tank valve is wide open.

     

    What in the blazes do you think is happening?

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