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I Forge Iron

ned

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  • Gender
    Male
  • Location
    Herts / Essex border in UK
  • Interests
    Lost wax casting

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  1. hi, thanks for input. I agree about boiling off the silicon ( looked up boiling point after posting ). Investment had been in the kiln for 32 hours so was dry, I had wrapped plaster bandage around prior to casting and this had dried , however I suppose some moisture could be absorbed by the investment although the core was around 450 - 500 degrees C before pour. Crucible only used for silicon bronze, heated to 700 C and allowed to cool a bit before re heating prior to charge being added. All metal was sprues, gates and ingots along with some finished cast pieces as apposed to actual scrap metal. All metal is pre heated in flame up to 450 - 500 degrees to drive off any moisture. Never used degasser before, although not having any issue with porosity in the cast ( decorative items ) I could grind the pink off but couldn't damage finished surface. Color didn't matter in this instance but wanted to find out the cause. Using silicon bronze so no zinc. I use a coagulant flux after charges melted to hold all the slag when pouring. Lost wax casting using proprietary bronze investment powder. Definitely no wax left in mould, have first hand experience of Vesuvius eruption caused by incomplete burnout. Thanks again
  2. Thanks Frosty, Color only appeared to be on surface however due to fine detail I was unable to remove. Items were part of decorative mirror. I hadn't meant to boil the bronze I had changed the lid of the furnace and achieved a superior melt in a faster time. The new lid really kept the heat in. I need to turn down the gas and air a bit to allow for higher efficiency. I only used all pre cast bronze as I needed a melt of 24 & 18.5 kilo and didn't have enough. Regards
  3. Hi there folks, this is my first post and I apologize by starting with a question. Have recently set up small foundry for casting bronze piecespieces using investment process, furnace and most equipment home made. Have achieved Some good results and learnt so much in the process. My last pour however resulted in the castings having a rose pink hue. My question is : Can this be attributed to metal getting to hot, it did start to boil in the furnace. Using only pre used bronze without any new metal. Pouring the metal at too high a temperature ? I will post info about myself the foundry and location this evening UK time. Many thankfor any input forth coming. Regards Ned
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