Welcome to another hobby that will consume your time and/or your money Herb..
1. The aluminum injection molds are either two side halves or top and bottom, For example my Kmold pintail minnow mold is side by side but if I shoot the mold and cut the belly off and place it back in the mold I can shoot the second color to get a top/bottom laminate, If you plan on doing this in larger scale production you would be better off finding a top/bottom mold with a divider plate or a blending block setup (Ask others on that one..)
For head/tail just put a little veg oil on one side of the mold and shoot the tail color cut the tail off or put your finger over where you want it to break and pull the other half...I cut because it makes a better finished product... place it back in the mold and shoot your second color. pretty easy..
2. Molds and injectors, check out Caney Creek, Lurecraft, Bears, Jacobs, etc. I started with a bears medium, I do not like my Jacobs injector (too small of a spout)
3. Remelting plastic...it should hit 340-350 degrees and turn liquidy... it will burn fast though, I use a hotplate not a microwave but either works well. Buy a gallon of plastisol when you get your first mold and injector, be sure to shake well, I have a small dowel I stir it with before shaking... start with 4 oz of plastisol heat until starting to get jelly like when It starts to turn clear add 6-12 drops of your color, glitter, scent .. As soon as it hits liquid state start shooting...
Good luck! post your first batch! Its like christmas when ya open the mold.
Oh and first and foremost read the DO NOT DO sticky, this stuff can be very dangerous
"Kids who hunt and fish dont steal and deal"
2012 NWR Bash Yellow Perch Champion
2012 Buggs Bash Champion