Hollow spots in stik baits

[stevebraddish@gmail.com]

I am a beginner and having problems with some hollow spots in my 4 piece injection molding of a 4.25 inch stick bait.  I was wondering if someone can give me some tips on whether I am likely using too much pressure or not enough or plastic too hot or not hot enough or do I need to hold the pressure longer.  Also, would using some mold release on mold prior help this situation.  Thanks!!!!

[biglewers]

Sounds like you are getting air bubbles.  When you first suck up the plastic with your injector, hold the injector 45 degrees and push the air out of the front of it.  This will allow nothing but plastic to go into your mold.  Hold some pressure and keep the sprue full of plastic. 

[Justin9j]

Where are the hollow spots?  Same place every time?

[stevebraddish@gmail.com]

mostly in upper portion but sometimes in lower portion as well.

[Justin9j]

It sounds like you injector is the cause either not full enough or maybe not enough
Volume to fill the mold. Or o ring problems

[Bugpac]

Pic of mold. Often stick baits its the design. Did not see who or what mold your using.