mark poulson Posted May 28, 2016 Report Share Posted May 28, 2016 (edited) Well, I took my time and made a two part, 3 cavity, 7" senko mold out of http://www.tackleunderground.com/community/gallery/image/15807-7-inch-senko-mold/ Edited May 28, 2016 by mark poulson Quote Link to comment Share on other sites More sharing options...
majic man Posted May 28, 2016 Report Share Posted May 28, 2016 From what I have seen, I have yet to see a denting problem not caused by gate size, or thick appendages feeding thru thin ones. 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted May 28, 2016 Author Report Share Posted May 28, 2016 If you look at the picture you'll see I drilled 11/16" holes thru the 3/4" mold perimeter for my injector, and then carved a smooth funnel down to the top of each cavity. I can't open the connection any more, or I'll be past the width of the cavities. I topped off the cavities as the plastic shrank. Do you think extending the mold perimeter another 3/4" would keep enough hot plastic available to stop the denting? Quote Link to comment Share on other sites More sharing options...
majic man Posted May 28, 2016 Report Share Posted May 28, 2016 Id carve more vents into it. Air pockets will dent as well. In a mold like this. One drop of plastic closes the vent off immedietly. I dont think a longer sprue is going to keep it dent free, as long as your keeping it topped off. 7" bait is a lot of plastic. Hard to keep dent free hand injecting. 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted May 28, 2016 Author Report Share Posted May 28, 2016 Since one of the cavities didn't dent, I'm thinking it's a matter of holding the pressure longer, even if it means I can only inject two cavities at a time. Or I may try pre-heating the injector, to give me more working time. It those don't work, I'll add some vents in the mid section. 1 Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 28, 2016 Report Share Posted May 28, 2016 Worth a shot Try shooting cooler, but skip the 10 second hold.... Wouldnt be much different than hand pouring Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 28, 2016 Report Share Posted May 28, 2016 Btw.. Ive been curious about adding wood glue to plaster.. Dont know why i havnt tried it yet??... But i will now!.... Thanks Mark! Quote Link to comment Share on other sites More sharing options...
Bassinfool Posted May 29, 2016 Report Share Posted May 29, 2016 I would try shooting cooler, hold pressure for just a few seconds and then move to your next cavity and repeat making sure to come back and top off. If that means you are only able to do 2 baits at a time but they come out right, so be it. If that doesn't work, I would try adding a few more vents and then try shooting cooler again. Quote Link to comment Share on other sites More sharing options...
Travis Posted May 30, 2016 Report Share Posted May 30, 2016 Worth a shot Try shooting cooler, but skip the 10 second hold.... Wouldnt be much different than hand pouring Close...it would be slower than hand pouring!!!!! Injectors popularity were for the ease of use, speed, and allowing anyone to make baits. Now we are taking one of the simplest molds to hand pour ( basically created the modern day popularity of making your own baits) and the "fixes" have managed to increased the time to make the baits, reduced the number of cavities, cutting vents in a straight stick that has no difficulties in filling in any way.... Shooting cooler the way to go. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted May 30, 2016 Author Report Share Posted May 30, 2016 I shot at 315, and held pressure for ten seconds each, and all three cavities made dent-free baits! I did find that I need to have a full cup of plastisol, or I get air in my injector, no matter how I try and avoid it. I think it has to do with the injector bottoming out in the silicone cup, and the filling being interrupted, but that's just a guess. I will make sure I have enough plastic to fill my 6oz injector without hitting the very bottom of the cup from now on. The baits came out great with the 4/1/1 mix of plastisol, salt, and blasting sand. They are soft (BJ soft plastic) but seem to be tougher than the GYCB senkos I have been using. They came out more green than the originals, so I'll be playing around with how much color I use, but that green color gets bit. 1 Quote Link to comment Share on other sites More sharing options...
Travis Posted May 30, 2016 Report Share Posted May 30, 2016 Glad you got it worked out. I wouldn't be happy about having to hold the injector for 10 seconds each however. Injectors should make things easier and faster (than hand pouring) if not no sense on using them (barring physical issues with shakes). 1 Quote Link to comment Share on other sites More sharing options...
MonteSS Posted May 30, 2016 Report Share Posted May 30, 2016 Nice. I would concentrate on/inject one cavity at a time. Quote Link to comment Share on other sites More sharing options...
mark poulson Posted May 30, 2016 Author Report Share Posted May 30, 2016 I guess I'll try injecting them at 315 without holding pressure next time, and see if that works. Fingers crossed. Quote Link to comment Share on other sites More sharing options...
SlowFISH Posted May 31, 2016 Report Share Posted May 31, 2016 Mark - good to hear it's working.... only suggestion I'd have is in the mold itself - While I agree with Magic Man's original assessment with regards to enlarging the size of spure to fix the denting if holding pressure wasn't working... but since you've fixed that by shooting with a lower temp - I would say a larger sprue should allow you to shoot and not have to hold pressure on it.... eliminate sitting there for 10 seconds. On a bait like that - I'd have left good 1/2" - 3/4" above the tip of the bait to act as a reservoir of hot plastic. Regardless - nice mold and good to hear you have it working.... hows the "wiggle" compared to the original? I love making my own designs/molds - but that damn senko has a wonderful little wobble to it - hard to beat it. J. 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted May 31, 2016 Author Report Share Posted May 31, 2016 My sprue is a full 3/4" at 11/16" diameter, and then tapers to the size of the senko in another 1/2". They seem to wiggle a little less than the originals, but it's very close. The feel firmer in hand. I may try a little softener in one batch, but I worry that it will make them as fragile as the originals. Of course, since I'm pouring them myself, they don't cost me $1 apiece anymore, so maybe I shouldn't worry so much about toughness anymore. But I like how mine hold up when I pitch them into heavy cover without getting torn off the hook. I'm just cheap and want to get more than one fish out of each bait, and I don't think the wiggle is as critical when I'm pitching them. Quote Link to comment Share on other sites More sharing options...
ipt Posted May 31, 2016 Report Share Posted May 31, 2016 the problem with vertical pouring/injecting on stick baits is the salt will settle to the bottom. if you're going to inject, make a new mold set up to side inject. the salt will still settle, but it'll settle evenly over the length of the bait 2 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted June 1, 2016 Author Report Share Posted June 1, 2016 ipt, I know you're right, because I used to hand pour my Ika molds at 335 to get the salt to settle more. But it doesn't seem to be a problem with the big senkos at 310-315. I stir the crap out of the mix before I suck it up into my injector. Quote Link to comment Share on other sites More sharing options...