Big Ray Posted May 16, 2015 Report Share Posted May 16, 2015 Ok guys I just bought the Do it Superfry mold. The only problem is every time I shoot it I get denting. I got a suggestion from someone that I should use a dremel to open up the gates on that mold more. I trust his suggestion but I was wondering if I can get some more advise from you guys. Thanks Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 16, 2015 Report Share Posted May 16, 2015 Ive never used a store bought mold, but would assume they shouldnt need any adjustments to work correctly... Most obvious reason could be temperature you are shooting at... One thing to try (if you havnt already) is to top off the sprue a second time after it pulls some of plastic down Quote Link to comment Share on other sites More sharing options...
DaveMc1 Posted May 16, 2015 Report Share Posted May 16, 2015 Ok guys I just bought the Do it Superfry mold. The only problem is every time I shoot it I get denting. I got a suggestion from someone that I should use a dremel to open up the gates on that mold more. I trust his suggestion but I was wondering if I can get some more advise from you guys. Thanks your problem with dents isn't the vents in the mold, it will be either the runner is too small or the gates are too small. you are either running out of reserve plastic to feed the bait as it cools and shrinks or the gate is cooling off before the bait does. Because of this little design flaw your only option may be to hold pressure on it a little longer. Quote Link to comment Share on other sites More sharing options...
Apdriver Posted May 16, 2015 Report Share Posted May 16, 2015 I bought two of their Thump Jig molds. It's the big one and I believe it's 3.5 inches IIRC. It dented horribly and that's what I did to make it shoot good baits. I just opened the gates with a round stone on my dremel. Now perfect little thumpers every time. I'd say go for it. For sure, you won't hurt anything as long as the dremel doesn't get away from you and that's unlikely. Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 17, 2015 Author Report Share Posted May 17, 2015 (edited) JRammit I tried shooting cooler didn't work. The only thing that changed is that the tails didn't fill all the way in. I didn't like the look of that. And Davemc1 I tried holding pressure and that didn't do anything ethier. That was the first thing I did after searching this forum for some advice. Thanks for the advice anyway. The only thing I guess I have left is to open up the gates more. That is the last thing I didn't do I just need to get a dremel. Apdriver I think Doitmolds needs to tweak there mold design so that doesn't happen any more. I don't know about you but I wouldn't consider myself a machinist. So if I end up fixing that mold I know they can. Edited May 17, 2015 by Big Ray 1 Quote Link to comment Share on other sites More sharing options...
majic man Posted May 17, 2015 Report Share Posted May 17, 2015 you can use a small round file as well just as easily. If its easier to acquire then a dremel. Quote Link to comment Share on other sites More sharing options...
ute Posted May 17, 2015 Report Share Posted May 17, 2015 Since I am old, bad eyes and shakey hands, I found that the small round file is a great option! Quote Link to comment Share on other sites More sharing options...
Apdriver Posted May 17, 2015 Report Share Posted May 17, 2015 Big Ray, I think you're right. What I don't understand is why didn't someone shoot the dang things before they sold them. I don't like having to fiddle with them in temperature, pressure, angle, or whatever the little secret is, to get good baits. Now, am I wrong? I don't think so,because as a customer, I have an expectation of good products upon purchase. IMO, not too much to ask. I compare it to buying a new car and having to hit the starter with a hammer to get it to start. 2 Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 17, 2015 Report Share Posted May 17, 2015 I've found that denting is an issue with many molds. Its always a trade off because often people want the gate mark on the bait as small as possible for the longest pretty lines. When I make a soft plastic mold I make the gate into the cavity as large as I can get away with. The larger the better for the most part. Another thing I do to minimize early gate freeze off is to place the cavity as close as practical to the main runner leaving the smallest practical web of metal there reduces its ability to sink heat off into metal of the mold. Problem solved!... Send that mold back and buy one from Bob! Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 18, 2015 Report Share Posted May 18, 2015 No. It's much cheaper to modify the one he has to work. I just added my 2 cents to help him want to do it. Seen some of your videos, you know your stuff!!... I may hit you up some day... Jeremy Quote Link to comment Share on other sites More sharing options...
archery1 Posted May 18, 2015 Report Share Posted May 18, 2015 you can use a small round file as well just as easily. If its easier to acquire then a dremel. i have a pack of small files that i got on;ine for bout 5$. think they are jewelers files? harbor freight has a pack of small files also Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 18, 2015 Author Report Share Posted May 18, 2015 Big Ray, I think you're right. What I don't understand is why didn't someone shoot the dang things before they sold them. I don't like having to fiddle with them in temperature, pressure, angle, or whatever the little secret is, to get good baits. Now, am I wrong? I don't think so,because as a customer, I have an expectation of good products upon purchase. IMO, not too much to ask. I compare it to buying a new car and having to hit the starter with a hammer to get it to start. We are on the same page. Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 18, 2015 Author Report Share Posted May 18, 2015 Problem solved!... Send that mold back and buy one from Bob! One day I plan on buying something custom from Bob. 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted May 19, 2015 Report Share Posted May 19, 2015 Will heating the molds first, like is done with lead molds, help? Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 20, 2015 Author Report Share Posted May 20, 2015 I wonder if that will work myself. When I was searching through this forum for advice someone mentions that. Quote Link to comment Share on other sites More sharing options...
DaveMc1 Posted May 20, 2015 Report Share Posted May 20, 2015 I wonder if that will work myself. When I was searching through this forum for advice someone mentions that. doubtful, as stated, your denting problem is either the runner is too small (which would cause a couple other issues) or most likely the gates are too small and not allowing sufficient material into the cavity as it cools and shrinks. Plastic expands when you heat it, as it cools it contracts, the gate needs to allow enough material to pass into the cavity as it contracts to avoid dents. A gate that is too small will solidify before the cavity cools blocking the flow of plastic from the runner and will cause dents. Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 20, 2015 Author Report Share Posted May 20, 2015 That took a minute for my brain to wrap around what you just said but I think I understand now. doubtful, as stated, your denting problem is either the runner is too small (which would cause a couple other issues) or most likely the gates are too small and not allowing sufficient material into the cavity as it cools and shrinks. Plastic expands when you heat it, as it cools it contracts, the gate needs to allow enough material to pass into the cavity as it contracts to avoid dents. A gate that is too small will solidify before the cavity cools blocking the flow of plastic from the runner and will cause dents. Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 23, 2015 Author Report Share Posted May 23, 2015 (edited) I got to take back what I said before DaveMc about holding pressure. I got tired of waiting to get my dremel so I tried doing what you said again but I shot with the plastisol at the temperature I normally shoot. I read on this forum about how I should shoot with cooler plastic and I also read that I should hold pressure so I combined the two ideas and it didn't work. But this time when I shot my plastic at the temp I usually heat it but held pressure they came out without dents. Edited May 23, 2015 by Big Ray Quote Link to comment Share on other sites More sharing options...
DaveMc1 Posted May 23, 2015 Report Share Posted May 23, 2015 I got to take back what I said before DaveMc about holding pressure. I got tired of waiting to get my dremel so I tried doing what you said again but I shot with the plastisol at the temperature I normally shoot. I read on this forum about how I should shoot with cooler plastic and I also read that I should hold pressure so I combined the two ideas and it didn't work. But this time when I shot my plastic at the temp I usually heat it but held pressure they came out without dents. If the mold was designed properly you wouldn't have to hold pressure, it still comes down to an improperly sized gate. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted May 23, 2015 Report Share Posted May 23, 2015 Big Ray - Well done for reporting back. Now we learn something positive. Dave Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 24, 2015 Author Report Share Posted May 24, 2015 Hey thanks Vodkaman. And Dave I agree with you. I don't like the fact that I have to hold pressure with the injector for the baits to come out right. I just wanted to let you guys know that it does help if you are having that problem. And I am still going to try and open up the gates when I get a chance so I won't have to do that anymore. I think I will send Do it a e-mail to let them know that they need to take care of that. I am surprised that more people don't mention that on there forum. But maybe they are just a bunch of yes men. Quote Link to comment Share on other sites More sharing options...
DF1 Posted May 24, 2015 Report Share Posted May 24, 2015 Search Super Fry on the Do-It forum and you will see it has come up a few times. If your not happy with your mold send it back, no need to rip people on their forum, many of whom are on this forum. Thanks, Your yes man Dan Quote Link to comment Share on other sites More sharing options...
Big Ray Posted May 24, 2015 Author Report Share Posted May 24, 2015 (edited) DF1 I was just kidding when I said that. You are right I didn't search there forum to see what other people said I just figured no one complained because the problem wasn't fixed. I checked like you said and I see that there are guys that had that problem. I take back what I said and I am sorry. Edited May 24, 2015 by Big Ray Quote Link to comment Share on other sites More sharing options...
DF1 Posted May 24, 2015 Report Share Posted May 24, 2015 Hey, I'm sorry for being grumpy, no hard feelings Big Ray. 1 Quote Link to comment Share on other sites More sharing options...
DaBehr Posted May 24, 2015 Report Share Posted May 24, 2015 What you are experiencing is called "differential shrinkage" a very common problem with any injection molded plastic part. It is caused by the skin of the bait setting, and when the dense body cools it will pull from the weakest point. Most commonly the closest skin. This is also know as "splay" in a hard plastic part. It could also pull from another part of the part causing it to warp. The common ways to overcome this in plastic molding is to lower the temperature of the plastic you are injecting, texture the location or reduce the thickness of the wall in that area of the mold so that there is no dense, hot core. But we all like those big body baits! There are some additives that can be used to minimize the issue..but we don't use those in plastic bait injection. At a cost of few thousand dollars you could add a heat element to that area of the mold so the skin doesn't set up as quickly. Have you noticed that after you shoot the mold a few times....and the mold is really hot....that the dent seems to go away? That's because the skin is not setting up as fast and becoming the weakest point for the core to suck from. But...it is pulling from somewhere else so you get a dent somewhere else or it will cause the bait a slight warp...which being soft plastic we don't even notice. The most common solution (for both our soft baits and for hard plastic injection) is to hold pressure to help push the hotter core out so the dent is less (probably not gone...just less). And yes...this problem comes up all the time on the Do-it forum....and it's still the same solution. Search Dents on the forum. I would suggest you inject the mold at the lowest temperature that completely fills the mold, and hold pressure for at least a 10 count. 2 Quote Link to comment Share on other sites More sharing options...
