538 Creature pour issues

[Brian TP]

Anyone have any suggestions on getting the small center tails to pour entirely on this mold?  I use the Jacobs Pro series usually at 18 psi, but no matter whether I raise or lower the psi, I get inconsistent pours on it.

The mold is the Basstackle 538 Creature mold.  The sprue starts at the top, winds down the side and injects into the bait cavities from underneath.  My temperature is good, its just not filling the small tail cavities. 

Worst case, I'll just cut them even but I did ike how long they were...

Thanks for the help in advance.

[Baitjunkys]

What temperature, Nubs are usually to cold.

 

[CNC Molds N Stuff]

I just looked at it.  Long thin tails like that are sometimes hard to fill.  Its not a matter of venting, but a matter of the fact that such a small strand of plastic doesn't carry much heat and the aluminum sucks it away to fast.  

People think of heat as temperature, but heat is energy, and a small volume of plastic (the cross section of that strand) will have less energy than a larger cross section of plastic like the body.  

Possible Partial Solutions:

Opening up the vents might allow it to fill faster which might allow it to fill before the energy is all drained away, but then there is more likelihood of flashing up the vents.  

Running the plastic at a higher temperature nearer the scorch temperature might help fill because there will be more energy packed into that tiny cross section and the amount of surface contact between the aluminum and the plastic remains the same.  It will take longer for the thick body to cool before you can demold.  

Getting the mold very hot before injecting might helps as there would be less difference in temperature and less potential to sink energy away.  It will take longer for the thick body to cool before you can demold.  

Filling faster might help, but I have no idea what a Jacobs pot is capable of.  Just for S&G have you tried hand injecting it?  Really fast filling molds creates a fairly high shock pressure as the mold reaches capacity and often they flash worse.  Kind of like shock breaking heavy braided line when you set the hook on a stump.  

If you get it figured out let us know.  

 

 

 

 

 

 

[uttexas]

Wearing full protection, have you tried injecting the mold from the side?

Agree with heating the mold if that doesn't work.

[Baitjunkys]

At 18 psi he is way out doing  what a hand injector will do, Get the plastic hotter, There is guys running thin appendages with a 60 degree mold temp chilled doing more than that. 

[Roger Linnell]

I've had the same problem and pretty much gave up

[Brian TP]

Appreciate the help.  I am guessing the heated mold might do the trick.  It's only 20`30 degrees here in NY and I turn the heat on right before I pour so that would make sense.  I usually start with cold molds because they do heat up so fast.  I will go back to using my hot plate again. 

I'm running my plastic at 345-350 degrees and any hotter sometimes yellows it.  I do not want to hand inject, spent too much $$ on the Jacobs.  lol

 

Thanks again!

[Baitjunkys]

if you are that hot already, carve a deep vent in there and break the tangs off after. could also loosen up on the clamps a bit.

[Roger Linnell]

31 minutes ago, Brian TP said:

Appreciate the help.  I am guessing the heated mold might do the trick.  It's only 20`30 degrees here in NY and I turn the heat on right before I pour so that would make sense.  I usually start with cold molds because they do heat up so fast.  I will go back to using my hot plate again. 

I'm running my plastic at 345-350 degrees and any hotter sometimes yellows it.  I do not want to hand inject, spent too much $$ on the Jacobs.  lol

 

Thanks again!

where in NY?

[Brian TP]

Near Pulaski, NY