joelhains Posted July 4, 2014 Report Share Posted July 4, 2014 (edited) Anybody here ever "ice" your molds to make demolding faster? I have only been injecting plastics a short time and most of my molds are just single cavity. This makes filling larger orders very time consuming. I've been trying to think of ways to make my production more efficient. One thing I've cone up with is "icing" the mold. It seems to be working fine do far but I've only shot about 30 baits thus way so far. Another question I have is for the guys heating plastic in the microwave. Is there a good way of keeping the plastic hot longer? It seems I only have time to shoot 3-5 baits before I have to heat the plastic again. I was thinking of trying an electric skillet and heating the plastic in the microwave and then putting the plastic in the glass containers directly on the skillet. Has anyone done this? If so how well does it work? Thanks for all the help guys! Edited July 4, 2014 by joelhains Quote Link to comment Share on other sites More sharing options...
alsworms Posted July 4, 2014 Report Share Posted July 4, 2014 As much as you'll hate me saying this, the best answer is always molds, molds, and more molds. The better you get, the more molds you'll want. As for keeping the plastic hot after the initial microwave burst, hot plates and burners are always best. Place them on mid-temp, transfer your cups from micro to burner, and you're good to go. Keep in mind that all burners are temperamental and will heat at different intervals. Once you learn the burner(s) you have, you should be good to go. Hope this helps a lil' Quote Link to comment Share on other sites More sharing options...
Painter1 Posted July 4, 2014 Report Share Posted July 4, 2014 An electric skillet is a good place to hold your heated cups. . Keeping your molds open helps dissipate heat and you can cool them in a freezer, but in the end, if you want to keep up much of a production scale you will need more mold Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted July 4, 2014 Report Share Posted July 4, 2014 Agree with the above, more molds, but as you need to start somewhere, I've found some options. 1. Clamp your mold being shot between some that aren't, they will cool it down, while reheating plastic, lay the halves down and sit cold ones on it. 2. Ice packs can be handy too. 3. have a break and throw it in the freezer for 5 minutes. Quote Link to comment Share on other sites More sharing options...
joelhains Posted July 4, 2014 Author Report Share Posted July 4, 2014 (edited) Thank you for the replies! Yes, I most definetly agree... I need more molds...Lots more molds! This is what I ment by icing the mold. I ment to post this already. Edited July 4, 2014 by joelhains Quote Link to comment Share on other sites More sharing options...
Frank Posted July 4, 2014 Report Share Posted July 4, 2014 I did not think you were actually using ice. That may work for a bait with large appendages but if you have a mold with thin ones they will be hard to fill. Your best bet is to keep them at a warm working temp. Setting them in front of a fan will keep them from over heating. Clamping them with other molds not being used will work to but when they get hot it will still take awhile to cool down. As for putting your Pyrex cups on a griddle, I have been doing that for awhile. Does not work unless you stir it once in awhile to keep the skin off the top. My main cups I never reheat just remelt the sprues and add them back in the main cups. Give the ones on the griddle a little temp boost. I use a high sided one in case of a spill and it won't get knocked off. I have a bunch of videos on you tube showing how I do it. Look me up and watch a few. My channel is Franksrooty2 , a couple of them are in the tutorials section on this site too. Quote Link to comment Share on other sites More sharing options...
nedyarb Posted July 4, 2014 Report Share Posted July 4, 2014 Five years ago I started injecting baits using a microwave and Pyrex cups. I gave up after a few months because it was so time consuming. But recently I tried it again but this time a bought a presto pot and I'm telling you it has been so much better. I just leave the injector in the pot so it stays warm and I don't have to clean it before every shot. I would strongly recommend not cooling your mold in ice water. Quote Link to comment Share on other sites More sharing options...
Mudd Butt Baits Posted July 4, 2014 Report Share Posted July 4, 2014 (edited) It comes to more cavities. I have two 7 cavities and a 3 for my frog. I use 4 cups of plastic and a microwave. Once to temp t takes me about 5 seconds to pour, minute to let set up, when I pull the worms I heat for 30 seconds and start over. I can do around 80-100 in an hour and 60-75 for the frog. Edited July 4, 2014 by Mudd Butt Baits Quote Link to comment Share on other sites More sharing options...
mark poulson Posted July 4, 2014 Report Share Posted July 4, 2014 I use an air hose from my compressor to cool a mold with compressed air so I can demold more quickly. It's like blowing on hot coffee to cool it a little. Aluminum transfers the heat away pretty quickly this way. But I'm a hobby pourer. If I were doing it for a living, I'd buy more molds, so I could do production with the minimum amount of sets. Time is money. Quote Link to comment Share on other sites More sharing options...
Richard Prager Posted July 4, 2014 Report Share Posted July 4, 2014 As alsworms says.....more molds.....period. or....don't prepare as much plastic.... You should have enough molds to pour out the batch you make up. Putting them in front of a floor fan helps allot after filling them. I think the bottom line is ....you are NEVER going to have enough molds and ALWAYS going to have left over plastic. If you you do buy a bunch more molds and really get into it....if you are married find a good Divorce Attorney! Quote Link to comment Share on other sites More sharing options...
SlowFISH Posted July 4, 2014 Report Share Posted July 4, 2014 I make my molds out of a urethane resin - so it insulates the bait ALOT more than aluminum.... which makes for long wait times to demold. Three things that I've found that help which haven't been mentioned... 1. After kicking the plastic over at 350 - I try to shoot the baits at temps closer to 300 - this drastically reduces how hot the molds get and how fast I can get the baits out. 2. I remove my baits and immediately drop them in a cold water bath (Some people frown against this - some people do it). I've found if I keep my molds lubricated well the baits will almost fall out of the mold once I open them - this lets me demold while they are still VERY soft which cuts down on time and since i dump them straight into the water - I don't get any deformities. (I hope that makes sense). 3. I nuke my plastic when I'm making 12 oz or less instead of using a presto. I've found that when the plastic is just sitting - keeping it in the microwave keeps it warmer than leaving it out on the counter. I've also made a small insulated "box" out of extruded insulation foam to keep the plastic in (and hot). It worked well in keeping the plastic hot longer as well. J. 1 Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted July 4, 2014 Report Share Posted July 4, 2014 2. I remove my baits and immediately drop them in a cold water bath (Some people frown against this - some people do it). I've found if I keep my molds lubricated well the baits will almost fall out of the mold once I open them - this lets me demold while they are still VERY soft which cuts down on time and since i dump them straight into the water - I don't get any deformities. (I hope that makes sense). Still on the sprue? Do you recycle sprues? Quote Link to comment Share on other sites More sharing options...
nova Posted July 4, 2014 Report Share Posted July 4, 2014 You'll think everything is fine and then one day you'll get a drop or two of water in the hot plastic and your whole world will change in an instant. Once you feel the pain you'll stop using ice. 1 Quote Link to comment Share on other sites More sharing options...
joelhains Posted July 5, 2014 Author Report Share Posted July 5, 2014 There are some great ideas here!I really like the idea of keeping tiles in the freezer. I have piece of granite counter top left over from a kitchen remodel I just finished that is about 18x24 inches. I think it would be perfect fit freezing and keeping mold cool. Quote Link to comment Share on other sites More sharing options...
curt k Posted July 5, 2014 Report Share Posted July 5, 2014 (edited) boulders are generally used in saunas and steam baths because they hold heat well , Heatsinks are units which are designed to dissipate heat .Aluminum makes a good heatsink because it drops the heat quicker than most materials . Heat and wet stone is a dangerous combination , the old school meathod of breaking up rock was to heat it then throw water on it , then the rock would shatter . I've seen rocks pop in camp fires because they were holding in moisture . My boss had his lip sewn up because someone threw a beer bottle into the fire pit , it basically exploded and a chunk of glass cut his face wide open I'm sure a warm mold wouldn't be enough to shatter a piece of tile , but a cold tile that has condensation from being in a freezer may very well shatter if any hot plastic gets dropped on it . It would probably have a similar effect as putting a measuring cup of plastic on a cold metal surface If I was to use anything to rapidly cool down a mold then I'd probably use a cooler ice pack . it would keep the mold dry , and it would stay cold for a fair amount of time Edited July 5, 2014 by curt k Quote Link to comment Share on other sites More sharing options...
curt k Posted July 6, 2014 Report Share Posted July 6, 2014 the exploded beer bottle was an empty bottle ,and it obviously it would have still had moisture in it since it was freshly drank and thrown in the pit . The impact of it was pretty clear to me .and actually a bit surprising to me cocidering the number of bottles I've seen thrown into the fires while in my youth The mold isn't going to get hot enough to crack up a tile , my point was that if hot plastic got spilled on it then it very well may . And yes a cooler pack will create condensation and more so than most things that come out of of a freezer and for sure it would create more than a tile , but I could throw one of those against a wall and chances are that it would stay intact Quote Link to comment Share on other sites More sharing options...
SlowFISH Posted July 8, 2014 Report Share Posted July 8, 2014 Still on the sprue? Do you recycle sprues? I open the mold and lift the sprue sightly and cut it either with a scissor or x-acto depending on the mold - then reheat them. I try not to reuse anything I've dumped in the water unless it's sat out for a day to dry. J. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted July 8, 2014 Report Share Posted July 8, 2014 I open the mold and lift the sprue sightly and cut it either with a scissor or x-acto depending on the mold - then reheat them. I try not to reuse anything I've dumped in the water unless it's sat out for a day to dry. J. Makes sense, sorry I was thinking if they were still red hot your plastic might still be molten inside, and cutting would cause issues. Quote Link to comment Share on other sites More sharing options...
Painter1 Posted July 8, 2014 Report Share Posted July 8, 2014 You'll think everything is fine and then one day you'll get a drop or two of water in the hot plastic and your whole world will change in an instant. Once you feel the pain you'll stop using ice. I could not have said it better. Save yourself a nasty burn and keep all moisture away from hot plastic. Quote Link to comment Share on other sites More sharing options...
SlowFISH Posted July 8, 2014 Report Share Posted July 8, 2014 Makes sense, sorry I was thinking if they were still red hot your plastic might still be molten inside, and cutting would cause issues. Yeah - I wish I could demold that fast!!!! LOL!! I still wait a decent amount of time - but I can see by the crater in the sprue how much the bait has cooled - if it looks like a volcano - it's good to open.... It's never too hot to handle - just in some cases too hot to hold shape if you try to hold or sit it down where it will deform on it's own weight. This condition is mostly the case after I've shot a bunch where the molds start getting hot over time and don't have enough down time to cool. J. Quote Link to comment Share on other sites More sharing options...
SlowFISH Posted July 8, 2014 Report Share Posted July 8, 2014 The insulation box is a very good idea. I like that. I may just copy that one. Make a formed foam tray that holds all my cups. NICE! Yeah Bob - it worked reasonably well - I use the silicone cups. I had some 2" extruded insulation laying around - so i stacked and glued it - bored some holes to fit the cups and then made a simple lid. A couple things I'd suggest - 1. Keep the cups close together - in case you are using a twinjector type setup - this way you don't have to remove them every time. 2. Leave an inch or two of the cup above the block you drop it in - this way you can get it out!!! This will mean your lid will have to have some thickness to make up the difference. 3. If you use foam - it will melt. ARRGHHH!!! Even my silicone cups got hot enough to melt over the bottom of the holes I put them in. After seeing this I just jammed some alum foil in there and that was good enough. If you are using a pyrex or something that transfers alot of heat you may want to line the bottom of the the hole with something more substantial and possibly think about lining the sides with alum foil as well to keep anything from melting and getting sticky. 4. I haven't tried this yet - but I'm tempted to ditch the foam and make one out of plaster - this way I don't have to worry about the melting issue and POP is a pretty good insulator as well. J. Quote Link to comment Share on other sites More sharing options...
Shane D Posted July 8, 2014 Report Share Posted July 8, 2014 Back when I dipped swim baits I made a plaster of Paris mold of a 2 cup Pyrex and once my plastic for the correct temp set it in the room temperature plaster and it insulated it for a good while then quick reheat and back to the plaster. Quote Link to comment Share on other sites More sharing options...
