I have a 3 ounce dual injector. I started making 4" flukes and all is going well.  Still trying to get the right amount of glitter per fluke.  Work in progress.  Overall, I'm pleased with the way the fluke turns out.

 

tried to do the 5" senkos, and that is a struggle.  When I inject the mold, the injector seems to stop prematurely in the process.  I thought it was full of plastic, so I stopped pumping.  After a few minutes, when I open the mold, the first worm in line seems to fill in with plastic.  The rest of the cavity's have only half the worm injected and the tubes are hollow.

 

I have tried the process over.  double checking that my injection temperatures were within range, which they are.  plastic is completely cooked.

I've gone as far as injecting the plastic, then when the injector stops, I immediately refilled the injector with plastic and follow the previous fill.  (I think it all has to be injected at once.  Can't follow with multiple injections.)

 

I am starting to think that the problems I am having are due to the difference in temperature from the hot plastic and the cnc molds.  The plastic is setting faster than I can inject.  I've heard some say to use a heat gun on the mold, or even a hot griddle. but wouldn't heating the mold cause the aluminum to warp?

 

Is a 3 ounce injector large enough for a 4 cavity, 5" senko mold?

 

any suggestions?

I do have a ribbon worm mold coming tomorrow, will I experience the same issues with that?

 

Pre-heating a mold shouldn't warp it. I have a toaster oven and put them in to warm them up in the winter. Try warming it up and shooting a few. A 3 oz injector should fill a 4 cavity stick bait mold. I have a 4 oz and have plenty left over. I also lube up my o-ring before 

I start shooting to make it run smoother. Basstackle has their injectors at a reduced price rn, if you want to get a 6oz. They're pretty good.

You might try using a Qtip and putting some cooking oil along the sides of the cavities.  Sometimes I have to do that with my baby brush hogs.

I bought my 3oz injector from basstackle too. Let me try and warm the mold up and I'll see how it goes. I'd certainly be happy if this 3oz injector could fill the senko mold.

 

I thought about lubing the mold. I've heard some ppl use the worm oil that you use for bagging, to lube the mold. I have a big bottle of that I could try. I'll do the lube first. If that fails, then I'll try the warming method. Then if that fails, I'll do both. 

 

Thanks for the input 

You might have to warm the mold and the injectors.  When it is cool I warm the molds and injectors while I am preparing the plastisol.

@JIGMAN what method do you use to warm your molds up?

I have a griddle from an old gas grill that I lay on top of a hot plate.   

What temp are you heating your plastic to?

350

Are you using heavy salt plastisol?

If so it takes more pressure to fill cavities.

Make sure your cavities are vented.

Tom

I'm using the red label - medium plastisol from dead on plastic.

 

the molds I have are vented

 

Well, the temperature difference between the mold and plastic was the culprit. I warmed the molds up to 300 and it did the trick. Downfall? Those molds take a long time to cool down, even after injected. Had to wait a good while before cracking the mold. So I might warm them up to 200 and see how that goes. The worms are coming out nice now. 

 

here's some pictures

 

I’m glad you got it figured out.  Can you post a pic of the stick bait mold?

@Jig Man - here's a photo of the mold I got.  I got it from Do-It Molds

 

Thanks for the pic.

 

300° seems very hot for the mold before shooting.  I try to heat mine to where I can pick them up with bare hands.  If you haven’t already done so a little cooking oil or worm oil will help the plastisol flow freer.  I dip the tip of the mandrel on my tubes before each shoot to avoid partials.