I was able to make my first test run of my DIY press today. Its a bit crude right now, but I got some good results. I'm using the Emory Cook Microfusion process that allows pressing with much lower pressures (100 psi). I based my press on a cheap 6 ton bench shop press. Its really a glorified car jack. Bought this at Harbor Freight for $100 US. While there, I also picked up two hot plates at $12 US ea. I used the two heating elements mounted to some 1/8" steel plate as platens. I was able to re-use the temperature controls from the hot plates. To run my tests, I needed powered plastic (PVC would be best). I used some 9mm polystyrene beads from the craft store. To convert them into powdered form, I ran them through a coffee grinder (burr type). My test pressing was a using a 1950's 7" stamper made for Apollo Records of NY. I was able to find a few of these at a flea market. Here is a shot of the press with the lower platen and stamper mounted with the powdered plastic spread on the surface:
A closeup of the stamper:
Top platen and ram installed:
The hot plate heaters are then turned on and I used an infrared thermometer to estimate when the heaters were at the correct temperature (about 250 C). I applied a light amount of pressure to fuse the powder and transfer heat for about 30 seconds. To complete the operation, I increased the pressure to the point that I felt some heavy resistance from the jack (it would great to be able to monitor the psi of the jack). I held this for 1 minute and then turned off the heat and released the pressure. I poured some water on the top platen to cool it so that I could remove the record.
Still attached to the top platen:
Removed and ready for play:
Here is a sample of the result:
http://home.comcast.net/~markrob1066/docs/Test1.mp3
The next step is to make things a bit more user friendly and faster. I want to have pre-heated platens and add a book-like fixture that contains the top and bottom stampers with the powdered plastic loaded. This will allow fast loading and unloading of the record. I'll make this from thin aluminum so that the heat transfer is fast. I want to make the platens out of thicker steel so that the heat is even and does not droop durning the pressing operation. I also want to use a better heat source, so that the heat is even across the surface. Looking to find a source for PVC either in poweder or pellet form that is available in small quantities. I'm also considering ways to re-grind old thrift shop records for re-use. All in all, it was a good first start. If anybody has interest, questions, or suggestions, I'd be most interested.
Mark