BTC Posted May 31, 2022 Report Share Posted May 31, 2022 I'm shooting a couple of ribbed grub molds, 5'' and 7''. Everything is fine except there are these weird little indents, only on the top side, on each rib. I'm not new to shooting molds at all and I've tried everything. Could this be a venting issue or is it something else. Any help would be great. Quote Link to comment Share on other sites More sharing options...
basskat Posted June 1, 2022 Report Share Posted June 1, 2022 I have a couple of molds with lots of ribs and I fight these as well. Pretty sure it's a venting issue. Quote Link to comment Share on other sites More sharing options...
Jim jarreau Posted June 2, 2022 Report Share Posted June 2, 2022 Is that the Epic 5” curly tail ? Quote Link to comment Share on other sites More sharing options...
SlowFISH Posted June 2, 2022 Report Share Posted June 2, 2022 Can you take a picture of the mold and upload? I agree fully with above comments - looks like its a venting issue. Are those bubbles just on one side - and I'd assume to be the "up" side of the mold when filled? SOMETIMES it can be solved with speed of injection (slower) and sometime with the plastic heat.... but in my experience, adding vents does the trick. I have lizard 2 molds I made with big ribs and only way I could get them to fill was by adding a vent on every rib. You don't need a massive vent - literally just the tiniest of a groove will let enough air pass through. I've even used an Xacto/utility blade and a straight edge to score deep enough to create vents. Scoring with a blade can/will create a high spot as you're really just moving the metal not removing it (like a ding in a car door)... but just use some fine sandpaper to knock it down. J. 2 Quote Link to comment Share on other sites More sharing options...
