Taking my 4x6 to the limit

[bmac2]

Yesterday I made a stop at one of the local machine shops that let me dumpster dive in the drops bin. I wasn’t looking for anything I was just driving by and didn’t see any cars (Cars? This is Alberta oil country) make that giant pickups in the customer parking area so I went and grabbed some Tim’s (coffee). I was telling them about my coffee can foundry (the Troll) and my adventures in cutting up a 4L V6 into small enough pieces to fit into a 3" x 6” crucible when they came up with 2 of these pistons. Someone had a very bad day judging from the deep scratches in them. I have no idea what they came out of just it was big. The pistons are 5 ½” in diameter, 6” long, with a 5/8” wall and tip the scales at just under 10lbs ea. They are definitely stretching the limits of the 4x6. Each cut took about half an hour but they should be good for castings. Thm:

 

[digiex-chris]

I don't know what you have planned for it, but if it were me, I'd keep track of it separately from the rest of the aluminum. That'll be valuable for IC pistons because it'll have high silicon content that most normal aluminum doesn't have, so it expands less with heat than say, 6061 and 7075.

 

[bmac2]

Hi Chris
I agree. In all the reading I’ve been doing on hobby casting and the differences in aluminum alloy I had made up my mind at the start to keep things separated. For pouring ingots I made up one mold out of angle iron that I use for cast. A tip here for anyone that might make one up. Cut the ends at a slight angle like the draft on a casting pattern or once the mold is hot you have to let the ingots cool before you can get them out. For pistons I’m making up another mold from some channel iron to form little gold bricks. Extruded . . . . it just gets the muffin tin. Connecting rods are another matter. They are truly amazing looking stuff and so far I haven’t broken any of them down just leaving them in a bucket. One of the first books I read on hobby casting suggested starting a book to keep track of everything you do in your foundry recording melt times, regulator pressure, aluminum type, gassed?, fluxed?, type of mold, etc. etc. At first I had to force myself to keep it up but now it’s just another part of the routine. With the book one tip I picked up was to give the ingots a number and log what they came from.