Job Posted October 2, 2016 Report Share Posted October 2, 2016 (edited) Hi guys, My second problem.. I am having a really a hard time with some top inject molds. I bought them for doing laminate injection. Half of my baits have air stuck in their heads (see the pictures). This is very frustrating, halves my production and ruins my fun in making lures. Who knows what I'm doing wrong here? I burp the injector and pour slow.. Edited October 2, 2016 by Job Quote Link to comment Share on other sites More sharing options...
Basseducer Posted October 2, 2016 Report Share Posted October 2, 2016 Are you topping off the mold right after injecting and keeping the gate full? This allows the mold to draw in plastic instead of air. Quote Link to comment Share on other sites More sharing options...
Job Posted October 2, 2016 Author Report Share Posted October 2, 2016 Yes I do, that is not the problem. Air just gets stuck at the top. Quote Link to comment Share on other sites More sharing options...
Baitjunkys Posted October 2, 2016 Report Share Posted October 2, 2016 Needs venting at the highest point. Quote Link to comment Share on other sites More sharing options...
smallmouthaholic Posted October 2, 2016 Report Share Posted October 2, 2016 Vertical ,fat belly baits in larger sizes have a problem getting rid of air. You can vent them 'till the cows come home and there will still be a problem Quote Link to comment Share on other sites More sharing options...
Baitjunkys Posted October 2, 2016 Report Share Posted October 2, 2016 I call bs on that. That clearly is air trapped above the top vent line. Simplest solution. A vent right across the gate line. This is not what I consider a big fat bait. 1 Quote Link to comment Share on other sites More sharing options...
Frank Posted October 2, 2016 Report Share Posted October 2, 2016 This will sound funny but if you take a utility knife and score a few vents right at the top going out both sides it will help a lot. But the real key is giving the injector or Twinjector a firm push at the end. One other thing I see is it looks like the Sprue is being pulled out when you lift it off to go to the next cavity. This happen to me sometimes but after the mold heats up it goes away. If you don't have many molds you might want to warm the molds a bit. With the Twinjector you might want to heat the block also. Also when using the Twinjector get thing done as fast as you can but make sure you give it a firm push at the end and move on to the next cavity. 1 Quote Link to comment Share on other sites More sharing options...
Job Posted October 2, 2016 Author Report Share Posted October 2, 2016 The thing is that it also shoots perfect baits... So I am not convinced it is a 100% venting problem.I tweeked a mold a bit by dremling some extra venting openings at the top. Hope that will work out.. Quote Link to comment Share on other sites More sharing options...
DaveMc1 Posted October 2, 2016 Report Share Posted October 2, 2016 (edited) I call bs on that. That clearly is air trapped above the top vent line. Simplest solution. A vent right across the gate line. This is not what I consider a big fat bait. That particular bait I would want to see a vent every 1/4" starting at the gate. I get a similar looking void in a very similar spot on one of my baits when the vents get clogged or plugged up. it's 100% a venting issue. Edited October 2, 2016 by DaveMc1 Quote Link to comment Share on other sites More sharing options...
Job Posted October 2, 2016 Author Report Share Posted October 2, 2016 This will sound funny but if you take a utility knife and score a few vents right at the top going out both sides it will help a lot. But the real key is giving the injector or Twinjector a firm push at the end. One other thing I see is it looks like the Sprue is being pulled out when you lift it off to go to the next cavity. This happen to me sometimes but after the mold heats up it goes away. If you don't have many molds you might want to warm the molds a bit. With the Twinjector you might want to heat the block also. Also when using the Twinjector get thing done as fast as you can but make sure you give it a firm push at the end and move on to the next cavity. Thanks Frank! Quote Link to comment Share on other sites More sharing options...
Baitjunkys Posted October 2, 2016 Report Share Posted October 2, 2016 Turn the mold upside down on your injector and see what happens. Gravity will show you why it needs a nose vent. Just saying. Quote Link to comment Share on other sites More sharing options...
MonteSS Posted October 2, 2016 Report Share Posted October 2, 2016 (edited) Gates too small and clogging But Leonard is the expert. Edited October 2, 2016 by MonteSS 1 Quote Link to comment Share on other sites More sharing options...
Baitjunkys Posted October 2, 2016 Report Share Posted October 2, 2016 To many people assume plastic fills the entire cavity and pushes the air all out the bottom. If you pour water in a hole it fills from the bottom up, plastic is rising pushing the air right back to the top, gate has plastic coming in. There is no were for the air to go. Except get stuck right in the nose. Gate has zero to do with this issue, if the air cant get out its gonna get stuck. If your cavity is equal in size to your flow, then it is very possible to push it all out the bottom. Tho this is not the case. Quote Link to comment Share on other sites More sharing options...
Baitjunkys Posted October 2, 2016 Report Share Posted October 2, 2016 Gates too small and clogging But Leonard is the expert. By far not an expert, I learn new stuff all the time. I got a pile of scrap eliminating these type of issues, so its more a trial and error, vs proclaimed expert. 1 Quote Link to comment Share on other sites More sharing options...
Apdriver Posted October 3, 2016 Report Share Posted October 3, 2016 Certainly all very interesting. I would have guessed small runner running out of plastic. Quote Link to comment Share on other sites More sharing options...
DaveMc1 Posted October 3, 2016 Report Share Posted October 3, 2016 Certainly all very interesting. I would have guessed small runner running out of plastic. If it was straight down in the centre of the nose then yes you would be right. Off to the side like that is a vent issue. 1 Quote Link to comment Share on other sites More sharing options...
