Mark- I posted a 'how to' last year (on forming poly), but can't find it, it must be back past 20 pages of posts and has probably dropped off the face of the Earth - it was pretty long winded anyway.
Here is a copy of a Word Doc I saved, which may be helpful.
pete
"I formed my first lips between 2 spoons with a paper clamp on the handles to apply the pressure. There is no need to get as exotic as this press I have made.
1. Get a small can, I used a SMALL discarded, chopped tomato can, something you can heat cooking oil on the stove and is narrow and tall. Put about 2" of cooking oil in it, I used olive oil (I have a cholesterol problem), but any cooking oil should do. Place the oil on a very low heat gas or electric burner and SLOWLY heat for a few minutes to get it around 170 C to 180 C (350-360 F). Tip- Hang a piece of Polycarbonate in the oil and periodically move it in the oil- when @ correct temp the Poly will start to bend easily, now lower the heat a bit so oil does not overheat, test every so often to make sure the temp is O.K. Don’t overheat the oil or it will blister or spall the poly.
2. The press formers, or whatever you use, must be close to the same shape, the lips I use are about 3/4"wide, 1 ¼” long 1/16” thick, and you will have to make the former plates to accept your required size.
3. Stand the former in the hot oil, making sure all the former and poly are immersed in the oil, leave for about 10-15 sec, you will see the top former begin to close on to the lower bending the poly under the pressure applied by the paper clamp, quickly remove.
4. Place the former on a damp wash cloth and wrap the cloth over the top, then press the plates together (a spoon is handy). Hold in position for about 5 sec's so the damp cloth can cool things a bit, lift the paper clamp, separate the formers and flick the new lip into a glass of water/detergent mix to cool and clean, then do another one.
Sometimes the poly is formed so well it sticks to the formers (suction) so you may need to slide it off the die into the water, be careful as the poly is still hot and you may push it out of shape.
This sounds pretty laborious but once you get the oil to the right temp, you could probably do 20 in 10 mins. You may see one lip in the photo is a bit cloudy looking, this one was placed in the oil when the temp was too low, and bought up to temp. and it did not form properly. Allow the oil to get up to temp before you place the poly and former into it and they will come out crystal clear as in photos. These lips have not been sanded etc, they are standard ‘Moores’ 1/16 “ lips, I have tried it with 1/8” pre cut lips, and it forms just as easily (see photo). Beware of over heating/ under heating the oil, as it will make the Poly craze and crack (too cool) or you may see small air bubbles in it (too hot)- this is caused by overheating, which causes the moisture in the Poly to expand.There is probably a 10-20 degree ideal range where it will form like butter. Also be aware of the usual HAZARD of water, hot oil and flame. Make sure the press is dry before immersing again in the hot oil.
Also see Poly properties etc- "
http://www.sheffieldplastics.com/fam_mak_poly.cfm