Propane tank/fueled furnace build

Discussion in 'Furnaces and their construction' started by Shawno, Dec 27, 2020.

  1. FishbonzWV

    FishbonzWV Silver Banner Member

    Hello Shawn,
    A6 is the size you need.
    Here's what I built.
    You need 4 sq ft of 2" wool, 1 for lid, 1 for floor, 2 for body.
    I put a drain in with a 7/8" step drill.
    If you want a flat floor, tamp some clay laden soil in and put the wool over it.
    I tacked 4 bolts to the lid and pressed the wool over them with small washers/nuts to hold in place.Then coated with 2 layers of Satanite.
    Welded a 1" x 4" pipe nipple for tuyere.
    Furnace1.jpg

    Here's my modified weed burner.
    Burner1-horz.jpg Burner2-horz.jpg
    3/4" x 8" pipe, fits in the 1" tuyere with a little hand grinding.
    I put a propane orifice in the end of the wand.

    When I built a larger A10 size furnace, I added a blower by modifying the burner.
    Burner4.JPG

    I've been using this rig for 7 years now.

    Applying the Satanite.


    You'll love the quick, easy use of the furnace.
     
    Last edited: Dec 31, 2020
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  2. Shawno

    Shawno Copper

    Thanks FishbonzWV.
    I had found the Insulating Wool/Satanite video couple of days ago but it was great to watch the whole process play out in the second video. Despite ordering too large a crucible for my planned furnace, I will go ahead and make the original propane tank furnace and use a smaller crucible. As someone else suggested, start with my original plan of a steel crucible, then maybe get a proper one once I get the hang of the process. I think my melts will be smaller ones anyways, compared to this one I watched in the video. I may shoot for a larger furnace in the future.

    Thanks
    Cheers,
    Shawn
    Happy New Year!
     
  3. Zapins

    Zapins Gold

    Keep the burner simple. I use a 1/8" black steel pipe from home depot or lowes plumbing isle connected to a pipe end cap. Then you have to order and use a #57 drill bit to get the perfect orifice size. Its that simple.

    You can get plumbing fittings that connect up to propane line too.

    IMG_20140304_013236_385[1].jpg
     
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  4. Shawno

    Shawno Copper

    Thanks Zapins. I have seen plans calling for .025 to .035" Mig tips. A #57 bit is .o47". That sounds huge. Does it matter on what size material the burner is ? ie 1/2" pipe? 3/4" pipe"?

    Because I wanted to move forward and experiment a but, I pieced together a burner today. 1/2" tee fitting to a 1/2"x6" pipe to a 1/2" coupling for a flare. The Mig tip orifice was .025, all as suggested in post #18. I figured I could size up if necessary, as Zapins suggests by drilling out the mig fitting to a larger one. I ended up soldering it in so it would be easier to drill up than size down.
    And if I botch it, I can replace it. I will try to get some photos in the next day or two.

    Running the burner in open air, it kept going out. I do not have a gauge on my propane supply (yet) so not sure what I was running at but I started low and worked up. The flame always went out til I started choking off the air supply. So thinking that with a .o25 orifice, 1/2" burner, a tee fitting as an air inlet is too much. So do I choke it down or go with bigger orifice as the next step? This will be a propane tank sized furnace. I guess what I am wondering/asking...for a given size furnace, what size burner? I see burner plans most often calling for a 3/4" burner pipe. But in the metal casting pdf I have, it suggests half inch pipe, and I had it all in stock so just experimenting now. Cool to see a burner in action. I feel like I got something done today! :)

    Also, does anyone know who makes Satanite? All I can find is a non-descript bag advertised and it is very rare (at least in Canada) What is with the plain brown bag wrapping? I found a local supplier who has stock on Kastite GP. Googling it, it seems like it will work. But I am wondering if I can coat ceramic insulation with it like Satanite or is Satanite really a unique product? Or should I mix the Kastite with Perlite and just cast my furnace with that? 4:1 ratio seems like a pretty consistent ration amongst the information I can find. I do have a small amount of Satanite coming but just trying to get my head around the various products and options (already thinking of my next furnace...;-) ) And my local suppler says the ceramic insulation is no problem so things are looking up.

    Any input for me?
    Thanks
    Cheers,
    Shawn
     
    Last edited: Jan 4, 2021
  5. Shawno

    Shawno Copper

    OK, so, to answer my own question, a company called Harbinson Walker International makes Satanite. MSDS sheet attached. Maybe for you in the USA, it is not an elusive product, but, apparently, from my last couple of weeks of searching, it is a unicorn in Canada (and Amazon.ca). I am looking alternatives to coat the Ceramic insulation.
     

    Attached Files:

  6. Petee716

    Petee716 Gold Banner Member

  7. Shawno

    Shawno Copper

    Out of stock
     
  8. Zapins

    Zapins Gold

    Hmm I had always thought it was made in hell but apparently they lost their license to Harbinson walker.

    What propane design are you using? A lot of the funky sideways L shaped burners use 3/4" pipe for the main tube. I think this is a bit unnecessary and difficult to make. Literally a straight pipe with a cap on the end with the hole drilled in the cap is all you need. You don't need an overly complicated L shape and vent holes drilled down the side.

    If you use the straight pipe design a 1/4" tube is all you need although if you already have the material then use the 1/2" it won't matter much.

    Running the burner in open air is not the same as in the furnace there is no back pressure or mixing effect like in the furnace. Though my burner does stay lit out of the furnace easily. I do not know if that is orifice size dependent. I'd guess that a smaller hole means faster flowing gas which might blow out the flame or cause too much turbulence to stay lit.

    I used #57 because an old post on backyardfoundry.com extensively tested many orifice sizes including the smaller ones and found the optimal size was #57. I've never personally had an issue with it and I have never personally tested smaller sized orifices (orifi?) So I can't add any new info on comparisons.
     
  9. Jason

    Jason Gold

    To add fuel to the fire (tongue in cheek) Furnaces can and do behave differently with the lid open or not!

    This is one of those things where you say to yourself you are building a furnace. Find something you can see that works and duplicate it. Cars work well with all the pieces in place, but it's kinda hard to ride an engine down the street sitting on the ground. Shawno, expect things to change as you still have to stick it in a furnace and shove some blown air at it.
    Fuel mixture can be a tricky thing at first, but it's not. It will take some experimentation because no two builds are exactly the same. Learning how to work through these problems will only make you smarter in the end and help you really understand what is happening. I tell guys, if you want easy, maybe consider taking up knitting.
    Stay the course, work the build and lean on us. I can promise one of us here will help you get it dialed in.

    I can easily light off my burner in open air, but it wouldn't melt a stick of butter like that! It's not until I stick it in my furnace and flip on the air will it get HOT. Even then, I still have to add more fuel to match the mixture to my blown air. If one of these things isn't correct, it will blow out.
     
  10. Shawno

    Shawno Copper

    Oh Oh ....it sounds like I am giving the impression that I am getting frustrated. I am getting sucked in deep into this rabbit hole....and having fun but not seriously frustrated...yet.

    I actually started a furnace years ago but only go as far as cutting the propane tank up. (which I saved and will be my furnace) I think back then I gave up before I did this amount of research, got distracted or something and moved on. At least, I started this time with the propane tank ready to go, and a renewed enthusiasm.

    I guess there is a little frustration but only because I find it hard to believe only one company makes the goto product Satanite. But, apparently, as Zapins commented, "Hmm I had always thought it was made in hell but apparently they lost their license to Harbinson walker."..lol And then throw in the closed borders, and no stock issues here in Canada. If things were normal, I would order it up to Minnesota, drive over and get it. Different times these days. So now I am just researching and experimenting with things. Making the burner was/is interesting. Working with an open flame is new to me....I am off to work today but will take a video tomorrow and post it to show it, but probably most of you know exactly what I am seeing. It won't be new to you.

    So, not seriously frustrated, just trying to keep this thread alive and show what I am finding, with the odd question thrown in...

    Thank you all for the input!
    Cheers,
    Shawno
     
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  11. FishbonzWV

    FishbonzWV Silver Banner Member

    I thought Rocco was going to check on this since it's down the road from him???

    Before you start drilling the orifice, try a 3/4" x 8" pipe. I think your short, skinny pipe doesn't give the gas time to mix properly.
    Burning outside the furnace...you need a flare on the end. (3/4" to 1" adapter)
     
    Last edited: Jan 5, 2021
  12. Zapins

    Zapins Gold

    This is for the L shaped burner where the tube mixes air with propane
     
  13. FishbonzWV

    FishbonzWV Silver Banner Member

    Everything needs to be proportional.
    Remember Metalabs 1" burner that didn't work? He reduced it to 3/4" and fixed the problem.
     
  14. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I don't think I would say just, but very similar. That's why it can be reconstituted with water if it hasn't been fired. It was formulated to be fire brick mortar.

    SATANITE Tech Data.jpg

    Probably worth noting as mentioned at Mark's link, Mullite is relatively inert and thus chemically resistant, which is aanother reason the the Smiths like it as a forge coating since they often use fluxes, so you will get some similar benefit by using it as a foundry coating on more susceptible materials.

    Best,
    Kelly
     
  15. Billy Elmore

    Billy Elmore Silver

    I will try to get some pics of my burner design. Simple as shit and will blow the lid off if I crank it up too high. I used a 3/4" black pipe and a .043 mig tip. Straight into the back of the pipe with no air restrictions. I cut a tee out and brass and mounted the mig tip in the center of the tee. Works very well for me so far. I have seen guys melting aluminum in steel propane tanks with no refractory and a small propane bottle for a crucible. I dont think I would recommend doing that to anyone but have seen it done without issues. I have a propane tank furnace myself and I used castable refractory. Poured the sides first and then used ram in the bottom. I made it a little less than two inches thick to give me a little more clearance around the crucible for lifting it out and besides... that is what size my form was.LOL I have not had any issues with the furnace getting too hot. The only issue I have had with my furnace is I dont think I can run gas pressure as high due to smaller area inside doesnt give it enough time to burn before exiting the furnace. Also the mig tip is a little bigger than some on here use. I have it about tweaked now and can melt brass in about 45 to 50 minutes from cold start.
     
  16. Shawno

    Shawno Copper

    I played a bit with the burner again today. I upsized the orifice to .035 but it did not seem to make much difference. Next, I will get some 3/4" parts and make another one. I need to figure out how to upload a video. But because of the daylight, the video does not show much. I will take another tonight.

    Billy, did you mix the castable product with perlite or anything to add insulation characteristics?
     

    Attached Files:

  17. Shawno

    Shawno Copper

    I have found a replacement product for Satanite that is available in Canada. Quote from the supplier...

    We don’t carry Satanite anymore. However, we do have an equivalent brand on hand called Mexi-komo, which also comes in 55 lb. bags. See attached data sheet. The price on mexi-komo is $0.55/lb. CAD.

    I also found a local supplier of a refractory called CW Kastite GP Castable. My options have opened up today....:)
     

    Attached Files:

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  18. Billy Elmore

    Billy Elmore Silver

    No sir...I got castable from work that had expired past its shelf life and they were going to throw it out. Its industrial grade for cast iron. All I did was mix it with water and pour it...way too wet... and it took over a week to dry out with a light bulb in it 24/7 and then a bunch of slow...low heat burns until I did not see any steam coming out of it. After that I cranked it up and let it get to operating temp and started melting. Made pulling the forms out super easy but afraid I can not recommend doing it that way as I think I just got lucky something didnt collapse or fail when I mixed it too wet.
     
  19. Billy Elmore

    Billy Elmore Silver

    Honestly if you are just melting aluminum this stuff will be fine. You could melt it without anything inside the tank and a stainless bottle for a crucible....seen it done...never did it myself. Just remember... I said all I wanted to melt was aluminum and two weeks later I was gathering brass for a melt.LOL
     

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