Thread: Mold Venting

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  1. #1
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    Mold Venting

    I have a plastic mold that I assume needs a few added vents because I am getting dimples in the bait is my thinking correct on this, Also with is the best way to add them. I was thinking using the scratch in the square and scoring a small grove

  2. Member
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    #2
    A hacksaw can work. Just work really slowly back and forth trying to keep it dead straight. It doesn't take much of a groove to allow air to escape.

  3. Member
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    #3
    It could also be that your plastic is cooling too quickly in the channel leading to the bait cavity, and it's not allowing more hot plastisol to be drawn into the bait cavity. This has happened with a couple of the injection molds I've made. Sometimes simply repositioning the mold so that gravity helps keep the bait cavity supplied with hot plastic is all that is needed. But other times I've had to open up the channel leading to the bait cavity.

    I think I'd look at something like that before I tried anything else.

    The only time I've found the need for adding vent tubes is when I am doing a curly tail or ribbon tailed bait. The vent hole allows them to fill much better. At least it has for me.

  4. Member basscatcher89's Avatar
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    #4
    Hand injector? You might just need to hold the injector down a little longer when you shoot. When you press down and it stops just hold it there for a bit. I've had the dimples on some of mine as well and that seems to help it.

    With molds that I've built typically I need more venting when I have parts of the mold that aren't filling up.

  5. Member Solitario Lupo's Avatar
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    #5
    How are you clamping it. Might just be clamping it to hard in those spots.

  6. Member
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    #6
    I’ve had some molds I had to use a lot of clamps on but that took care of it. Some I slowed down on when shooting & held pressure for several seconds. I’ve had a few that I also put other mold halves behind before clamping to act as a heat sync to keep molds cooler when doing multiple shots & that worked good too. Plastic getting a little to hot can cause problems too which will make you think it’s a vent problem when it’s just a little to hot.

  7. Tin Boats Moderator Pokie Pa's Avatar
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    #7
    Good advice above. Try them first. I needed to add some vents and I used a scroll saw blade. That blade makes a small
    channel and perfect…. IF YOU NEED A VENT. Try the suggestions above first.
    Tim Messer ~ Lake Ariel, Pa.
    US Army 1968 ~ 1971

    2019 Ranger RT188 ~ Merc PRO XS ~ MK Ultrex

  8. Member
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    #8
    thanks guys i will try these and see what happens