So once again I need to consult the Oracle that is THF. I had another attempt at the stove tool over the weekend with varying degrees of success. I tried the parting down technique as suggested by a number of you. I was really pleased with how this turned out and was feeling quite confident at this stage. And the following pictures show the mould with the pattern removed (although the clay core mould was modified after these photos). The pattern came out really cleanly ... The bronze was poured in at the head end of the tool. The core running up the handle is a piece of 15mm copper pipe with the end blocked off with clay. I felt the pour went okay and initially the turn out looked good ... until I pulled the whole piece out of the sand when I noticed a distinct problem. This is best explained with a few more photos ... The side you can see in the above photo is the drag side. The top half of the cast turned out wider than the bottom half My initial thinking was that maybe the cope lifted a little at casting time but I think the failure would look different if this was the case. I recorded the poor and watched the video back and there's no sign of this happening. The only other thing I can think of is that the sand wasn't packed in tight enough around the pattern in the cope and the molten bronze compressed it, thereby enlarging the cavity as it filled the space. Otherwise, I'm at a loss as to how this occurred but I assume it was a fault with the mould somehow. For interest, here's a photo of the end of the handle complete with hollow pipe (roughly sawn off) ... Also for the record, the clay core mould was constructed with DAS air drying clay and it worked a treat. Cheers, Gavin
