Wexcoat Binder

Discussion in 'Investment casting Ceramic shell method' started by amber foundry, May 30, 2021.

  1. amber foundry

    amber foundry Copper

    Finally got around to trialling the Wexcoat shell binder with suspension flour. It was necessary to pre wet between a few of the layers as I was unsure how well it would adhere to a very dry layer. It appears to be very weak in its green state and I managed to snap part off after 6 coats ! I rejoined it with fire cement and carried on. I was very concerned re de wax and vitrification as this was my first shell casting attempt, I eventually decided to use my blow torch with the shell under a stainless steel beer keg. I was very pleased with the outcome (see pic) pre heated in furnace exhaust and poured in bucket of sand with some blanket for support. 20210530_101109.jpg 20210530_115719.jpg
     
    Jason and Tobho Mott like this.
  2. Ferrisbeu

    Ferrisbeu Copper

    very nice
     
  3. Jason

    Jason Gold

    Ya done good!
     
  4. Gor

    Gor Lead

    This seems to be the only post here on Wexcoat, and I have a bucket of it and some flour and grit and not yet started, but a table full of wax angels all patiently waiting.
    So do keep up these posts. Keen to know if it will actually keep and for how long. I cannot even find a decent manual for it, just what special plasters advised.

    I see no sprues. So you dewaxed with a blow torch, but then did you fire it?

    More please!!
     
  5. amber foundry

    amber foundry Copper

    Hi Gor, UK based :)
    It's a DIY process for sure, I couldn't find any information either, I just mixed at 2 to 1 ratio for about ten minutes and left it for a day before re mixing. You have to be careful not to drag air into the slurry as it takes on the appearance of shaving foam.
    So I left it again for a few days before use.

    I couldn't find any details re dewaxing or vitrification for the stuff either so choose a path from all the available literature.

    I didn't think it required any further risers due to its simplicity so just went for it. I use a polystyrene cup to make the pouring cups so started by burning that away with the torch I then decided just to go with it placing a beer keg over the top and playing the has torch on full under but around the edge, there was a small exhaust on the top of the keg, I just watched the wax pour out and once that stopped kept the torch going and playing it directly on the shell until I guessed it was cooked. Once cool enough I pinged it to test and it was done, no splits or cracks. Even the repair that I'd made was fine, I found it very weak when green but I left it 4 days after final coat before dewax.

    I used about two coats of the fine 2 coats of medium and 3 coats of the course with a final dip. ( I should have made notes)

    I will be checking the slurry next week and guess it may need stirring up again but we'll see.
    I normally use investment casting but thought this would save time for certain things, I will be shelling a more complex hollow shape next week. Fingers crossed.
    Feel free to ask any questions.
    Where are you based ?

    Regards
    Ian
     
    Last edited: Jun 3, 2021
  6. amber foundry

    amber foundry Copper

    I will also be adapting my large kiln to burn out the shells and re cycle the wax,
    I can just place them inside at 900 degrees and leave them for 10-15 mins.
     
  7. Gor

    Gor Lead

    Hi, thanks, I am down in Devon. Ok sounds like a learning curve for us both.
    I have made all sorts of strange creatures in wax and they are about to experience a trial by fire. Only the virtuous will survive!
     
  8. amber foundry

    amber foundry Copper

    Good luck
     

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