Ribs not filling help!

[jannercast]

Hello everyone

I've been reading the forum for a while now and picked up some great tips from you guys but I'm having an issue currently with a ribbed bait.

Although not a Do-It mold (I have some in order) I thought this would be the best place to ask.

The issue I have is the majority of the ribs fill but some of the ribs only half fill and I'm really struggling to work out why.

So far I've tried soft plastic and supersoft plastic (from the UK).I've tryed the mold cold and hot. I've tryed the mold lubed and not lubed. I've tryed keeping pressure on from 10-40 seconds.

I've now run out of ideas so hoping you guys can help me out, here's some pictures although a bit difficult to capture the ribs.

[andrewlamberson]

It's hard to tell by the photo...but it looks like to me they are denting...vs. not filling. It may also be that those ribs need to be vented and the displaced air is being pushed to the end of the rib.

I would heat your plastic (1st time) to 350 Degrees F and then let it cool to 320 F and then inject. The hotter the plastic is...the more likely you

Let us know if that helps.

[jannercast]

Thanks for the advice Andrew, will give that a try at the weekend.

Here's a slightly better picture -

[Bob]

you need to shoot the mold very slow. the slower you inject it the better.

[2XL]

I had a similar problem with the ribs not filling with the ring it mold. I slowed down how fast I shot the mold and now get decent baits.

[andrewlamberson]

That last pic really looks like trapped air. As the plastic fills the mold ...and displaces the air in the mold....the air needs to escape through the vents. If you inject too quickly the air gets trapped at the end of some of the flow paths instead of being pushed out.

[Lamar]

  I say to slow down too. I had that problem with one of my molds too. You need to give the air time to push out the vents.

[BareKnuckleJigs]

IF the mold has the cavities on only 1 side of the runner, Your job will be easier.  With the mold ready to be shot, sprue-up, set the tip of the injector in the sprue (injection port), lift the vent-end of the mold, leave the runner-side-corner of the mold on the table, so the vents are the highest detail in the mold...shoot S-L-O-W.  Let the liquid plastic "flood" the interior of the mold like a boat taking-on water...slowly rising and filling the details of the cavities.