Posted by Jack Davis on September 30, 1998 at 10:58:46:

I have been shell casting only a few weeks, with fair success, but am having a consistent problem. I am having shrinkage in the areas between thinner and thicker areas of the sculpture which causes undo porosity. I realise that these are normal problem areas and cooling and insulating, or re-design proceedures can be used to help them, but it seems that I am pouring into a overheated shell. I have talked to several techs, and am getting several different responses. I have heard of shell temps from 1100 to 1800 degrees. I have been pulling my hot casts at 1750 and usually getting the silicon bronze pour within 30-40 seconds. My metal temp seems perfect at 1930 deg., as my pour cup has little shrinkage there. The size of my castings end up weighing between 15 and 40 lbs. The thickness in my sculpture range from 1/4 inch to 1-1/2 inch in extreme cases, but I am having the same problem in area which are much more proportional My problems lie in heavier areas where the bronze may be staying in a molten state for to long of time. Some of these areas are very hard to get to to force cool with air. I know I am going to need to experiment, but some basic temps advice would save me a lot of time. Thanx

• Imagemaker Arts and Collectibles

Follow Ups:

• Re: Pouring temps for shell Robert Oblon 11/03/98 (0)

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