Quote Originally Posted by slabeye View Post
I have a question.....ok you say 350 degrees. I have problems with dimples and when I inject the top half it runs until the bottom half, with the hotter temps. 320's seems to work better for me...is that normal? or am I doing something wrong....
Lots of things going on here. For the dimples, make sure your mold is warmed up. Shoot a couple loads thru it and leave them in there for an extra 30 seconds before de-molding so the mold sucks up the heat. When the mold is warm, shoot your plastic on the cool side, say in the 320 to 330 range and then hold some light pressure on the injector after the rod stops....15 seconds or so, see if that doesn't help eliminate the dimples.

When you're doing a split body color shot, you need to inject the second color slower than normal. If you inject fast, you're using too much force and the plastic going in the gate will lift the color already in the mold and run under it as well as over it. The incoming plastic sort of floats the plastic that's already in the mold. Just slow down the injection speed.

The 350 degrees seems to be the universal temperature to assure the plastic' conversion from the raw state to usable. 350 is NOT necessarily the optimal working temperature. Every mold is different in how its likes to play and at what temperature. Then by introducing split colors to the mold and plastic a whole new set of rules come about regarding the mold and working temperature. It takes time and practice to iron all this stuff out and since everyone does things differently there are no set rules to follow, only suggestions. The rest each person has to tailor to his own way of doing things with his molds. It all comes together, but when you have some free time sit down and use junk plastic to practice some of the techniques that are giving you problems and you'll find your way.