Pattern Making for the Mechanically Challenged

Discussion in 'Pattern making' started by mrhomescientist, Dec 4, 2019.

  1. I hope everyone's Christmas was a jolly one.

    3rd coat on the body is done and it's looking great. I cured it with the weed burner, then fired it up with the lid on just to see how it went. Looks and sounds beautiful.
    IMG_20191227_163327.jpg

    You can see to the left I'm also making a plinth out of IFB. I figured I'd coat that in or or two layers of satanite too; what do you guys think?

    I also noticed significant gaps around the edges of the lid. So I guess on the last coat I'll have to try and smooth out the top surface somehow.
    IMG_20191227_163350.jpg


    Also, this thread has went pretty far away from my original question, so if any mods would like to rename it to something more appropriate feel free.
     
  2. FishbonzWV

    FishbonzWV Silver Banner Member

    Keep building up these areas until they are flush with the metal. Then spin the lid as you apply a couple more layers. You'll get a solid seal.
    MHS Furnace.jpg
     
    joe yard likes this.
  3. Melterskelter

    Melterskelter Gold Banner Member

    Not saying this is the answer for everyone, but I use a "gasket" of wool 1/2 to 1" thick at the junction of the lid and furnace body. That gives a good seal for a few melts and then tends to shrink and harden some so that it is necessary to put on another thin layer. I adhere the wool to the body by buttering it on the down side with satanite. I have done that several times right before full firing. It seems to stick well as I guess the water is quickly driven out and then the satanite vitrifies. I am sure some would object to loose fibers as a health concern.

    Even rather small jets of flame will pretty rapidly cause the metal they are passing over to rot away as scale. So, I pay attention to maintaining a good seal.

    Denis
     
  4. Jason

    Jason Gold

    I've seen some place a rope shaped piece of kaowool like fire resistant material. It would be perfect as a lid gasket if built into the top of a furnace.... I just deal with some small flames exiting the joint.
     
  5. Melterskelter

    Melterskelter Gold Banner Member

    Are you thinking of the multi strand Kevlar used to seal wood stoves? I tried that stuff a couple times. As long as it makes a perfect seal it holds. As soon as a tiny jet occurs it melts.

    Denis
     
  6. Jason

    Jason Gold

    Yeah that's the stuff.. No good huh?
     
  7. Melterskelter

    Melterskelter Gold Banner Member

    Nope. I had hopes, but it has too low melting point. Otherwise it would be perfect.

    Denis
     
  8. Would it be possible to butter up either the lid or the rim of the furnace with some Satanite, put a layer of sandwich wrap over that and seat the lid so that the Satanite conforms to the lid surface?. That's a tactic that works for refractory cement.

    When I get some time, I'm going to use some loose silicon carbide grit and lap the lid to the body for a better fit, the lid seal has been bad since I added the extra half a keg extension to the top. If I rotate the lid around the vertical axis with a thick abrasive slurry, I should be able to get a good seal with the dense castable refractory.
     
    Last edited: Dec 28, 2019
  9. Melterskelter

    Melterskelter Gold Banner Member

    Mark,

    Interesting idea on the sandwich wrap and making conforming surfaces between lid and body. That will get some future use. I am not sure how well that will work with Satanite as it does not seem to do well in thick layers, but maybe so.

    Denis
     
  10. OMM

    OMM Silver

    If I was using any applyable refractory, I would level it out the best I could by hand and quickly put a layer of parchment paper followed by a sheet of glass or mirror. And add some pressure with a little bit of vibration. 2 to 3 days later pull the mirror off, peel off the parchment paper or burn it off.

    Repeat the steps for the lid.

    Then take top and bottom and give them a slight friction fit.

    I had a little bit of a problem with my IFB‘s . They were pretty damn flat to begin with but with a sharpie marker I friction fit them. But… I was still getting some small Visual leaks when I push the flame about 1 foot out of the exhaust hole.

    I have done more friction fitting and fluffed up the ceramic wool bace to ceramic wool lid. I also filled in where my screws are with ceramic wool, (as Dennis gave me a thumbs down on doing this with stove gasket). My last run I push the furnace really hard for 15 minutes. (I need to do something with the exhaust hole. It is in the works) but everything else looks to be good.

    This is the flame leaks set in stone by temperature colour on the stainless steel.
    B539145A-48FC-4C69-80B7-222514769538.jpeg

    In this next picture where you see any black carbon buildup, there is next to nothing for leaks. The hot gases (if we use the lid for reference) passed through from 11 o’clock to 3 o’clock. This also referenced true on the exterior stainless steel.
    C78BA78A-91C0-4C22-8282-2193B0D486E7.jpeg

    I think I got my leaks sealed up enough now to be just stupid and go for cast iron.

    But, as I stated. I have some attention required to my exhaust. I feel it is pushing the 500° C. But you got a love the colour!
    F05B55E3-9D9D-45BB-9F46-6A72CE9E7067.jpeg
     
    Last edited: Dec 28, 2019
  11. I'd cast the furnace chamber first, gave it a few swipes with a silicon carbide brick to knock off any irregularities and then set up the lid metalwork in position along with a chipboard disc to block the chamber level with the rim. The chipboard disc moved a bit during the vibration phase so I had to grind a few extra bits off but by and large it works so long as your formwork is solidly in position. It ended up in one video I made from about the 2:22 minute mark onwards, at the 5:40 mark you can see the cast surface as well as a step caused by the disc moving down during casting.

     
  12. Petee716

    Petee716 Gold Banner Member

    I'd try Bonz suggestion first or you could take 1/2 inch or so of wool and impregnate it with satanite, lay it on the furnace body bare and then clamp your lid down tight with plastic so it doesn't stick to the lid. Once it's set up replace the plastic with cardboard and fire it in place. It might stick to the body. That would be an improvement but would probably require maintenance. Nothing is really one-and-done anyway.
    I made my last furnace with solid refractory and formed the interface pretty much like Mark did but I made the lid first and then seated onto the wet body refractory. It works well, but I'm never too comfortable around it which is as it should be. Pressure and cumbustion issues aside, think "safe zone".

    Pete
     
  13. FishbonzWV

    FishbonzWV Silver Banner Member

    The method I described is how I did mine. It created a perfect seal and no matter what orientation you put the lid back on it still seals. The Saran wrap method would only work with a hinged lid which never varies the position of the mating surfaces.
    He could finish the seal in thirty minutes if he would quit treating the Satanite like castable and just fire it after application. Most of that thirty is cool down time.
     
  14. Hey I'm just following the vendor's instructions! :p
    I don't have anything to do with it until DavidF finishes the coins, so I might as well take it easy. I'm not in any rush.

    I'll fire the final coat today and see how the seal looks. I'll probably need to build it up a little more as you suggested. I thought about laying down a final thick layer on both mating surfaces, then using a grout trowel or something to smooth it flat.
     
  15. Finally got around to building up and curing the mating surfaces, and the seal still sucks lol. What I'm thinking now is I'll put the lid down on top of the furnace, and start spinning it around with a bit of downward force, to grind the two surfaces together and wear down any high spots. Satanite seems to grind back into powder pretty easily, with sandpaper at least.
     
  16. DavidF

    DavidF Administrator Staff Member Banner Member

    Lol, I'm sitting here fighting the lil printer.
    Having trouble getting the first layer to stick to the build plate. Seems to be a common problem.
    Going to crank up the thermostat in the house and get the resin warmed up a bit more...
     
  17. Good luck! Very eager to see the results.
     
  18. FishbonzWV

    FishbonzWV Silver Banner Member

    Paint it, spin it, fire it.
     
  19. Let me make sure I understand. You're saying paint a layer onto both surfaces, set the lid on top of the furnace, spin the lid around a few times against the surface, then fire?
    My concern is that my satanite dries up very quickly when I paint a new layer on. The moisture gets sucked up by the underlying layers, so in less than 30 seconds it's already cakey and won't spread very smoothly.
    I know you mentioned it before but it still hasn't fully registered, I guess. Sorry about that.
     
  20. FishbonzWV

    FishbonzWV Silver Banner Member

    Try it, you'll like it.
     

Share This Page