Landry Posted March 28, 2017 Report Share Posted March 28, 2017 I make a 10" top hand pour swimbait that holds about 5oz plastisol. I am finding it hard to get rid of the dipped in V or groove on top that happens due to shrinkage. It seems impossible to avoid due to the large mass of plastisol - perhaps I could lower my pouring temp but it still seems unlikely to solve the issue. Bait runs amazing and muskies approve but the groove bugs me. Was thinking of moving to a two piece mold and adding sprews in the back/top. What do u guys think? . Quote Link to comment Share on other sites More sharing options...
mark poulson Posted March 28, 2017 Report Share Posted March 28, 2017 You might try pouring to near the top of the mold, letting it cool enough to shrink, and then topping off the last little bit with hot plastic. I used to pour 6" swimbaits, and I noticed that the ones I laminated with three pours had little or no shrinkage. I've never injected that big a swimbait, so I can't help you there. Quote Link to comment Share on other sites More sharing options...
Landry Posted March 28, 2017 Author Report Share Posted March 28, 2017 That's a simple idea. Let each layer cool a bit. Nice. How long did u wait between layers on that 6" bait??? Your ideas, experience and answers on here are amazing btw. Thanks!! Quote Link to comment Share on other sites More sharing options...
mark poulson Posted March 28, 2017 Report Share Posted March 28, 2017 24 minutes ago, Landry said: That's a simple idea. Let each layer cool a bit. Nice. How long did u wait between layers on that 6" bait??? Your ideas, experience and answers on here are amazing btw. Thanks!! I usually poured two molds at a time. I would cook and mix all three colors first, to get them ready. Then I would put the first two back in the microwave, heat them to 340, and pour the first one. When I thought it looked like it had cooled enough not to mix with the second, I'd reheat the second and put the third color in the microwave with it. I'd pour the second color, and then heat the third color to 340. By the time I had the plastic ready, the second pour was firm enough to pour on top of, and I'd top it off with the third. By putting two colors into the microwave at the same time, I was trying to keep the plastic hot enough to make bringing it up to 340 quicker. It was not an exact science for me. I just looked at each layer of plastic after I poured it, and tried to judge when it was cool enough to pour over. It was almost like a jiggle test, where I'd shake the mold a little to see how the plastic moved. One interesting thing I found was that, even though the laminates held together really well when I fished them, I was able to pull them apart pretty cleanly afterwards, once the plastic had gotten torn up and I wanted to salvage the weighted hooks to reuse. Quote Link to comment Share on other sites More sharing options...
Landry Posted March 28, 2017 Author Report Share Posted March 28, 2017 Thanks. I will try that. Quote Link to comment Share on other sites More sharing options...
Anglinarcher Posted March 28, 2017 Report Share Posted March 28, 2017 Mark's laminate method will work, once you get the bugs out of your pour by trial and error. As for injecting, a large sprue used as a reservoir would be necessary, and is how the monster plastic pours are normally done. The hand pour is tricky, but modifying your mold to provide that reservoir for shrinkage, then trimming once cool, should work. Quote Link to comment Share on other sites More sharing options...
Landry Posted March 28, 2017 Author Report Share Posted March 28, 2017 I was thinking of a two piece mold with an oversized sprue that could be trimmed off later. Quote Link to comment Share on other sites More sharing options...
Anglinarcher Posted March 29, 2017 Report Share Posted March 29, 2017 And that will work well. Quote Link to comment Share on other sites More sharing options...
IBHUFFY1 Posted March 31, 2017 Report Share Posted March 31, 2017 (edited) Heat gun can be your friend Edited March 31, 2017 by IBHUFFY1 Quote Link to comment Share on other sites More sharing options...
Landry Posted March 31, 2017 Author Report Share Posted March 31, 2017 15 hours ago, IBHUFFY1 said: Heat gun can be your friend Can I explain this to me. Quote Link to comment Share on other sites More sharing options...
Bogbaits Posted April 1, 2017 Report Share Posted April 1, 2017 Also try pouring all the way to the top,let it settle then top it off,wait a little bit till it starts to firm and flip the mold over,this has worked on some of my molds in the past,also experiment with demolding the bait early in the drying process Quote Link to comment Share on other sites More sharing options...
Landry Posted April 1, 2017 Author Report Share Posted April 1, 2017 I am moving to silicon. My previous mold was POP. Settling always happened after quite a wait and topping off didn't seem viable then as I was skeptical it would adhere but I will try it. Flipping is a wired idea. I like it. Taking them out early warps them - tried that. I have decided to leave my new mold as an open top pour and find a way to reduce shrinkage rather then add top sprues. Some shrinkage is inevitable but I just need to reduce it. Thanks everyone. Quote Link to comment Share on other sites More sharing options...
Anglinarcher Posted April 2, 2017 Report Share Posted April 2, 2017 Plastisol expands when it is heated, shrinks when it cools. reducing shrinkage is impossible, compensating for it is necessary. Good luck on your attempts. Quote Link to comment Share on other sites More sharing options...
IBHUFFY1 Posted April 2, 2017 Report Share Posted April 2, 2017 On 3/31/2017 at 5:06 PM, Landry said: Can I explain this to me. I use a heat gun to warm the top layer of plastic and then pour another layer. A swimbait that has developed an uneven/depression from cooling can be filled in this manner. 1 Quote Link to comment Share on other sites More sharing options...
Landry Posted April 2, 2017 Author Report Share Posted April 2, 2017 I see. Sounds like an easy idea. Can I do this with a silicon mold??? Quote Link to comment Share on other sites More sharing options...
Anglinarcher Posted April 2, 2017 Report Share Posted April 2, 2017 Silicon can handle temperatures to 395 degrees F, and more for a short time. Plastisol converts at 350 degrees, and is usually re-melted and poured lower. NO PROBLEM with the heat gun if you don't over do it. 1 Quote Link to comment Share on other sites More sharing options...
Landry Posted April 3, 2017 Author Report Share Posted April 3, 2017 thats a good idea gonna try it thanks! Quote Link to comment Share on other sites More sharing options...
DoubleT Posted April 4, 2017 Report Share Posted April 4, 2017 This is a 18' long musky bait that I pour. I use a silicone mold. Shrinkage is definitely a issue if I pour to hot. If I pour around 330 it isn't quite as bad. 1 Quote Link to comment Share on other sites More sharing options...
Landry Posted April 4, 2017 Author Report Share Posted April 4, 2017 Thank s again. Looks nice. Quote Link to comment Share on other sites More sharing options...
