Stick bait bubble issue at the tail area

[2scoopsPLZ]

So when im shooting my 5" stick bait mold with a different colored tail, I started noticing big air bubbles forming right where the body meets the tail and once those air bubbles pop it leaves a huge crater right at that spot that makes the worm unusable. I noticed the bottom 2 worms usually shoot fine but the top 2 are the ones that get the huge air pockets. I assumed it was a temperature issue so I shot them hotter around 390-400 and it still did it with no difference. Any ideas?

[WALLEYE WACKER]

Try changing temp and less pressure of second color most of the venting on worms seems to me is at the tali.

[andrewlamberson]

Bubble = Trapped Air.

As you inject the plastic the air it is pushing has to go somewhere. If the lower vent is already covered by the tail color the air has no where to go.

So, it is best to cut the tail just below a vent. It is possible that some of the air might bubble up through the plastic to the next vent, but it is unlikely.

Give a look to where you are cutting the tail and see if that helps.

[ctom]

I posted pretty much the same info right after ww made his post, but the up-grade must have nixed it. That's a lot of plastic going into those cavities and if the tail piece is beyond the vent things won't turn out well.

On another note though, you'll likely do a bit better injecting a cooler plastic. Maybe in the 325-320 degree range and it helps to hold some pressure on the plunger after it stops and/or add a bit of plastic to the injection port. .

[2scoopsPLZ]

Bubble = Trapped Air.

As you inject the plastic the air it is pushing has to go somewhere. If the lower vent is already covered by the tail color the air has no where to go.

So, it is best to cut the tail just below a vent. It is possible that some of the air might bubble up through the plastic to the next vent, but it is unlikely.

Give a look to where you are cutting the tail and see if that helps.

Thanks. But if this were the case, why would the bottom 2 worms(the first 2 to mold) turn out fine, but the top 2 have this bubble trouble almost ever single time?

[2scoopsPLZ]

And should I be aiming to shooting these at lower, higher, or normal temperatures?

[ctom]

Thanks. But if this were the case, why would the bottom 2 worms(the first 2 to mold) turn out fine, but the top 2 have this bubble trouble almost ever single time?

Because the venting goes from cavity to cavity and the bottom cavity fills first and bottom to top. If the tail pieces are too long, going past the vents for the upper cavities, there is no way for air that's forced upward to get out.

And on the temperature, this was already addressed...."On another note though, you'll likely do a bit better injecting a cooler plastic. Maybe in the 325-320 degree range and it helps to hold some pressure on the plunger after it stops and/or add a bit of plastic to the injection port".

[efishnc]

Depending on your colors (whether or not a core color showing through might be a problem), the E-core tail should solve your dilemma... and this would have you recycling less plastic as well.