Keeping plastic hot

[Denny Welch]

My first injection pour went well.  It beats hand pouring 10 to 1, in my opinion.  I made a few mistakes (squeeze out on the claw mold....didn't clamp tight enough), hollow places in the carrots (plastic too cool?) and stuff like that.  I'm sure the fixes will come with more experience.

I've noticed in subsequent pours that my plastic seems to lose heat fast.  I'll bring my plastic up to 335-350, fill the injector and pour once.  There's no way I can fill the injector again before the plastic is too cool to use without reheating.  I've seen some videos, like Frank's, where he seems to keep his plastic hot for several minutes while he shoots the video.  Frank also has some stainless steel stands where he puts the molds when he pours.  He's also got something behind those stands where he keeps his hot plastics.  I'm wondering what he's doing that I'm not. 

Thanks in advance for your thoughts.

[pjmcla]

I can't keep my plastic "shootable" for as long as frank either.  Here is what I think Frank is doing that you and I,  the "amateur injector", are not.  He has a griddle that he keeps his plastic and injectors on.  He works "hot".  He pours a lot of baits; his injectors stay warm to hot, his molds stay warmer as they are bundled, and his plastic is sitting on a griddle.   
There are a lot of discussions on the plastics forums on the subject of keeping your plastic ready to shoot, without scorching.  I find that once molds get "to temperature" injecting goes much smoother.   That's why I bought my wife a new hair dryer. ( I did take the old one ).  Just don't run the hair dryer and the Microwave off the same plug at the same time  .   1,250 watts of hair Dryer + 1,000 watts of Microwave  =  Blown 15 amp fuse.

[Jason]

Jim posted a pretty good idea some time ago.  He made a plaster cup holder that he can sit his Pyrex in while he isn't using it.  The plaster gets warm and keeps your plastic warm longer.  I haven't tried it, but it's on my long list of things to do.

Jason

[MicroSpoons]

Jim posted a pretty good idea some time ago.  He made a plaster cup holder that he can sit his Pyrex in while he isn't using it.  The plaster gets warm and keeps your plastic warm longer.  I haven't tried it, but it's on my long list of things to do.

Jason

thats what I do as well, cut an old coffee can down and fill it a few inches from the top and push your cup down in to it.Let it cure for a couple of days to make sure all the moisture out of it so it wont crack when the hot cup goes in it. Holds the heat it very well Great for winter time pouring.

[BareKnuckleJigs]

Hollow spots...are those "hollows" in the "head", closest to the Runner?  If those hollows are close to the runner, make sure You fill the Sprue/Gate where You shoot into...pour a bit of plastic into it after You've injected...fill it up...if it runs, it's ok.  When that plastic cools and shrinks, if You don't fill up the Sprue/Gate, the shrinking plastic will draw an air pocket down into the mold and quite possibly into Your bait cavities, leaving You a hollow head in some/all of Your baits.

[Muskygary]

Frank uses a griddle to set his plastic on. He said he turns it up to 400 degrees to help keep the plastic warm. Im going to try this for my core shot worms. Takes a long time to make a bunch as you have to work with single cavity molds.

[BareKnuckleJigs]

I considered "hot plates" and griddles when I was getting geared up to do this, but my main concern with them was just how hot do they get...and how low is the "low"?  I couldn't find ONE that had an actual Temp setting, it was all "Warm, Low, Medium, High", and there were different "wattages".  How would one choose the right heat source, as per this discussion?

[knifemaker3]

I use an electric skillet to keep my cups warm.  The thing that allows Frank to keep his hot for so long is the fact that he is using a griddle as well.  Plus, it really seems like he is keeping it warmer longer than usual but in reality he is pouring more baits at once than most of us do who only pour say 1 or 2 molds at a time.  We have to wait for the mold to cool enough before demolding and get much less production.  Frank gets more due to using enough molds that he doesn't have to stop and wait as much......make sense?
My plastic will stay up to temp for as much as 5 minutes or more before it has cooled enough to reheat.  Depending on how many molds I'm pouring and how hot they are (the hotter they get the longer it takes to cool down enough to demold) I can usually get at least 2 pours in before having to reheat.  That is complete with demolding time.  On baits where I have more molds or are pouring all the same color on all the molds I have the first ones have a chance to cool before I'm done shooting all of them and are ready to demold by the time I'm done shooting so I don't have to stop, sit a minute waiting to cool down, and demold.

That is why is is important to keep an infrared thermometer handy to check temps of plastic.....you can better tell when you are still good to go or if you need to reheat.

You'll find that the more molds you own the less down time you'll have....at least for me that has been the case.

Good Luck!

[firetiger]

I bought an electric skillet and it has the temperature readings on it.  It will go up to 400 degrees.  I turn it up to 400 and leave it there.

The skillet is big enough to hold 4 pyrex cups.  Two have hot plastic and the other two I put my sprues and plugs from the injector.

I leave the two with hot plastic in the skillet the entire time I'm shooting.  The other two with the sprues and plugs go into the microwave.  I melt that plastic and then pour the plastic into the two pyrex that do not move from the skillet.

As you can tell, I watched Frank's videos very closely!  He's got some great tips.

If anyone has a more efficient method, I would love to hear it.  I'm still looking for ways to speed-up the injecting process.  I feel like I should be able to shoot more baits than I do, but I am hampered by only having one mold for a particular bait.
 

[knifemaker3]

fire tiger......you don't have to remelt your hot plastic cups at all?  I leave my skillet on 400 degrees and still have to reheat after about 5 minutes or so?

[pjmcla]

I thought about getting a small griddle to set my pyrex cups on but was concerned about scorching the plastic. ( You should see a skillet after I scramble eggs ).  With a heat setting of 400 degrees on the skillet are you stirring the plastic relatively often?  Have you had any scorched plastic issues.  I have seen a video where the gentleman had made a holder in a small tub. with what looked like spray foam insulation.  If that is what he used; I have no idea how he kept if from sticking to his pyrex cups.

[ghostbaits]

Ultimate solution is..... Get more molds!!! LOL!!!

I shoot until my plastic is gone, hand pour whatever is left as the injector can't get it all and then get another cup or 2.

With flake and the stabilizer slowly evaporating off, keeping plastic warm to long is hard anyway in a pyrex cup.

My presto with stirring paddle is the ultimate for larger loads. In a week or two, I will be cranking those bads boyz up and running a color in each. One night will be junebug, green pumpkin and bama bug night!!! Then pick others for the next night like black/red flake, watermelon red flake and watermelon red: black.... Works great and you get LOTS of baits done for the tournaments coming soon!!!

Jim

[Denny Welch]

Thanks, guys...all great posts.  I initially thought of using a hot plate, but whoever mentioned the electric skillet idea got the old mind to thinking.  If I could sneak the skillet out of the kitchen and into the garage my wife and I could have a contest to see who's stuff tasted better.  All of you could be the judges.

I think Jim's idea was the best...get more molds.

Thanks again for all the posts.  Every one of them was helpful.

[firetiger]

fire tiger......you don't have to remelt your hot plastic cups at all?  I leave my skillet on 400 degrees and still have to reheat after about 5 minutes or so?

One pyrex (#1) stays on the skillet the entire time.  The other pyrex (#2) is on the skillet also, but it has sprues and plugs. 

When pyrex #1 gets low, I put pyrex #2 into the microwave and melt it.  Then pour pyrex #2 into pyrex #1.  Stir and this will keep pyrex #1 ready to go.

Then repeat, over and over and over again!

The ultimate solution is getting more molds, but I only pour for myself so it's hard to justify a lot of molds.

[BareKnuckleJigs]

We love to help, Mr. Denny, Sir!