basscatcher89 Posted January 23, 2014 Report Share Posted January 23, 2014 My first Injection mold came the other day and I was out in the shop using it for the first time last night. I had a quick question. I noticed when I shot some of the grubs the bodies would have a thin flashing coming off where the mold joins together. I was curious if there is something I am possibly doing to cause this or is it just nature of the beast. Its no big deal cause it usually pulls right off the body but I wasnt sure if there was something I could be doing to avoid that. Thank You Quote Link to comment Share on other sites More sharing options...
DaBehr Posted January 23, 2014 Report Share Posted January 23, 2014 Flashing is caused by: 1. The plastic is too hot. You should initially heat your plastic to 350 degrees so that it fully "changes state" from the liquid to the plastic. If you don't get it hot enough you will end up with cloudy or sticky baits. If you are over heating your plastic it has too much "flow" causing the flash...plus it will start to burn and/or turn yellow. You do NOT want your plastic to burn!!!! It is a toxic event if that happens. Make sure you are using a good digital thermometer and stir you plastic as you heat it. Do-it sells a really good digital thermometer that I strongly recommend. 2. You may be injecting your plastic too quickly. Inject slowly. Light pressure on the injector handle. Too fast or with too much pressure can cause flash. 3. You may need (depending on the mold) to let your plastic cool a bit. Maybe to 330 or even 320. 4. You may need to double clamp you mold if it is the clamping type (vs. bolts). Make sure you tighten them securely but your not trying to smash the mold! Good luck...you'll figure it out. Take notes on the plastic temperature that works best so you remember next time! Quote Link to comment Share on other sites More sharing options...
basscatcher89 Posted January 23, 2014 Author Report Share Posted January 23, 2014 Ok you gave me some places to look. I've been heating to 350 and shooting from there I will try to let it cool off a bit more before I inject and I will back off the preassure on the injector as well. Its a del-mart grub mold so it has the screws built into the mold to hold it closed. 1 Quote Link to comment Share on other sites More sharing options...
smallmouthaholic Posted January 23, 2014 Report Share Posted January 23, 2014 1-Use C clamps or a vise to hold your molds closed. 2-Make sure both ,inside surfaces of the mold are clean and smooth 3- open the palm of your hand and let the weight of your hand push the plunger downward 4- Stop when you feel the slightest resistence 5- Use a medium viscosity plastisol and check the temp. w/ an IR gun Remove the tip from your inject and lightly spray the inside w/ PAM cooking spray-after you pull the plunger all the way out. Slowly depress the plunger until the gasket comes out and wipe all the excess plastic off. A smoothly operating injector is paramount to your sucess.Repeat the cleaning and lubricating process as necessary. Quote Link to comment Share on other sites More sharing options...
ipt Posted January 23, 2014 Report Share Posted January 23, 2014 most likely you are pushing too hard on the injector. once it stops its done, you dont have to force it in there. just make sure you top off the molds as the hot plastic shrinks Quote Link to comment Share on other sites More sharing options...
DAWG1419 Posted January 24, 2014 Report Share Posted January 24, 2014 Clamps Quote Link to comment Share on other sites More sharing options...
gone2long Posted January 24, 2014 Report Share Posted January 24, 2014 Yep clamps you can even produce flash with a clamped mold, remember that these injectors produce incredible forces you may be creating pressure so high that the mold is separating causing your flash. Quote Link to comment Share on other sites More sharing options...
