Casting Demo
Host Ted Dearing
June 3rd 2000
Ted Dearing (on left in red shirt) was kind enough to do a demonstration on aluminum casting for the group. Here he was showing samples of some of his past casting projects
Ted likes making his patterns from Styrofoam. He is indeed as Paul Pierce so eloquently described, "the McGuyver of metalworking and machining" Here Ted is showing off his hot wire foam carver. Simply its a frame holding a solid strand of wire, connected to an old model train transformer to regulate the heat. It slices through the foam like butterRight; Here Ted shows another hot wire Styrofoam cutter. This is for cutting slabs of foam into thinner sheets.
Interestingly enough, Ted used River silt/sand from the local Salt River bed. With a little water mixed in it holds its shape quite well and is very fine. Here he is showing where he keeps it and mixes it. He keeps it in this container, which are split plastic barrels supported on an angle iron stand. He mixes the water/sand one side, if too wet he'll draw dry material from the other side.
On the left picture, Ted is showing his "flasks" nothing more than 2x material and plywood. In the middle, Ted had laid the pattern (small blue line above the 2x2) in the bed of sand. He shook through a sieve a very fine layer of sand below over and around the pattern then added a small piece of electrical conduit and packed the rest of the material around the form. The conduit goes all the way to the pattern. This is where the molten aluminum is to be poured. Since the pattern is foam, there is no need to split a flask. So the entire process could be done here. Ted did show us the typical way of casting however:
Left, you can see the pattern in the flask, then middle you can see the opening for the pour, right, furnace is lit and being warmed up
Left, you can see the crucible that Ted uses and one of his clever inventions, he used a pair of vise grips, made a handle with a T to grip and pour the crucible without any contortionism! Way to go Ted! Middle pour in action, Right, just after the pour. (Note: TED DID CHANGE AND PREP FOR THE POUR!)
Left, picture after the pour, middle, Ted prepping to pour the extra aluminum into the sand, he made a depression in his sand bin to recover the excess. Right, he was about to shake out the sand to see our part
Left you can see Ted picking out the sand from the void in the sample part. On the Right the Finished product!
All in all a very worthwhile meeting, I believe everyone learned something and I think several of us are either starting or getting ready to start building our own furnaces. Our many thanks to Ted Dearing for his hospitality. We also got to oogle over his experimental airplane.