Excellent point about Lost Foam Casting. I have made patterns out of foam to make aluminum patterns. Just make sure you compensate for the shrinking of the casting that occurs during cooling. In general that is 1/8" per foot.
Take Hawkeye's advice about the fumes from foam. If you ever get a whiff of it you'll make sure you never do so again. Make yourself a hot knife to cut the foam. It can be used indoors as it does not produce much in the way of fumes. I like the idea of coating it with plaster. I used diluted wood glue in the past and it required several coats.
If you use a broken plastic part for a pattern in general it is a good idea. One word of caution, make 100% sure it is NOT PVC. The fumes from PVC are extremely toxic.
Consider buying a pattern maker's scale from Travers, McMaster, Grainger, or a foundry supply company. For a foundry supply company find one that caters to artists/sculpture casting. They will provide consumables in sizes that are appropriate for the backyard foundry. There was one in Tulsa OK I used in the past, just cannot remember the name. Paxton Patterson still supplies school foundry's, but tends to be pricey and does not carry nearly as much as it did in the past. One can find mason's trowels that will substitute quite well. A foundryman's spoon is fairly easy to make. Ditto for a riddle. I used a 5 gallon bucket to make a riddle. Cut it down to 4 or 5 inches tall and cut most of the center out of the lid. Sandwiched some fiberglass screen between the two pieces and had a nice riddle.
A foundry flask is also very easy to make. Look on YouTube for examples.
You guys got me Jones'n to build another foundry. As if I already didn't have enough projects to tackle. I need to post more pics of my car lift project and the big honking hole in the floor of my shop.
Take Hawkeye's advice about the fumes from foam. If you ever get a whiff of it you'll make sure you never do so again. Make yourself a hot knife to cut the foam. It can be used indoors as it does not produce much in the way of fumes. I like the idea of coating it with plaster. I used diluted wood glue in the past and it required several coats.
If you use a broken plastic part for a pattern in general it is a good idea. One word of caution, make 100% sure it is NOT PVC. The fumes from PVC are extremely toxic.
Consider buying a pattern maker's scale from Travers, McMaster, Grainger, or a foundry supply company. For a foundry supply company find one that caters to artists/sculpture casting. They will provide consumables in sizes that are appropriate for the backyard foundry. There was one in Tulsa OK I used in the past, just cannot remember the name. Paxton Patterson still supplies school foundry's, but tends to be pricey and does not carry nearly as much as it did in the past. One can find mason's trowels that will substitute quite well. A foundryman's spoon is fairly easy to make. Ditto for a riddle. I used a 5 gallon bucket to make a riddle. Cut it down to 4 or 5 inches tall and cut most of the center out of the lid. Sandwiched some fiberglass screen between the two pieces and had a nice riddle.
A foundry flask is also very easy to make. Look on YouTube for examples.
You guys got me Jones'n to build another foundry. As if I already didn't have enough projects to tackle. I need to post more pics of my car lift project and the big honking hole in the floor of my shop.