michalosixxx Posted March 18 Report Share Posted March 18 Hello guys, Do you have any ideas how to create perfect vent holes while making 2 part mold? How big should they be? The bigger = better? More= better? I am struggling with some tiny holes when im casting. I think i should make some more space for air to get out. Or am i wrong? Could you please tell me your opinion? I will appreciate for photos as well. Quote Link to comment Share on other sites More sharing options...
jigmeister Posted March 18 Report Share Posted March 18 "Perfect" vent holes are the ones that accomplish what you are attempting to do . I don't remember ever getting them right the first try. Mold orientation when pouring is critical to this process so the resin fills from the bottom of the cavity up . I first pour a bait and see where the resin voids are from any air entrapment . You want the resin filling the cavity to be pushing the air out of the vent ahead of it . You did not mention the type of material your mold is made from but Separate the mold halve and look at the portion of the mold that is not filling . I always start by scribing /cutting a small line in the mold face leading away from the part of the cavity the void is occurring at . with a mold made of a hard material this can be accomplished with the tip of a sharp nail or awl . If you mold is made of silicone you will need to use a razor knife making small cuts . Air will pass thru these small vent line easily so start small and keep increasing the size of the vent(s) until you're happy with the finished bait Quote Link to comment Share on other sites More sharing options...
michalosixxx Posted March 18 Author Report Share Posted March 18 I have a silicone molds. Interestingly, i still get small voids even using pressure chamber. Quote Link to comment Share on other sites More sharing options...
michalosixxx Posted March 18 Author Report Share Posted March 18 I thought that it will eliminate all the bubbles. Maybe i should try to set higher PSI , now i used 40-45 psi. Quote Link to comment Share on other sites More sharing options...
