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Hi All,
I apologize if this was already asked, but what is the best way to not get bubbles when you inject your plastic into a mold? I have tried sucking into the injector slower and faster to see if that makes a difference, but it doesn't seem too.
Anybody have any ideas?
Thanks,
Kyle
Do you have bubbles in the cup before you shoot? Not all molds are equal some will trap air if not properly vented.
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No bubbles in the cup before.
Are you getting bubbles or is the mold not filling properly?
Try letting plastic rest for a minute or so after heating. Look for trapped bubbles stir real slow.
I pour directly from the cup into injector put cap on then push until I get the air out.
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I don't know what type of plastic that you are using. also if you are staring too much you are going to get a lot of bubbles in whatever you do when you're stirring do not use wood use a metal steering rod also like it said above if your mold for not properly made so the air can escape when you are shooting you are going to have problems make sure that all the error can escape properly again do not over mix your plastic. I won't get into the issue on plastics but some of the different plastics have more bubbles than others when you are mixing them. in which mold are you having problems with.
Thanks Guys,
I am using a mold from Jacobs Baits and the plastic I am using now is from MF. I have started not stirring as much and at the moment I am just using a 14mm wrench because I don't have a metal rod. Maybe the shape of the wrench is causing it? Also, how would I know if the mold isn't properly made? If I pour it when it is too hot would that cause bubbles in the mold? I don't see visible bubbles in my plastic when i put it in the injector and the bubbles in the baits are big enough that I would see them in the Pyrex cup.
I sent you a PM .Quote:
Originally Posted by JKR06
after you draw your plastic, are you turning the injector upside down at a 45 degree angle(ish), and slowly pushing the plunger until a solid stream of plastic comes out, to purge the air from the injector tube?
you were exactly right I guess I forgot to mention that but I usually shoot some plastic out of the injector before I put it to the mold that was one of my biggest mistakes when I was starting out.Quote:
Originally Posted by H2oHammer
I draw it into the injector then inject some back in to the cup until it is a steady stream, but I don't turn it upside down.
try turning it upside down, and tilt it at a 45...pause a couple seconds to let it settle, then push your plunger. you will see air bubbles coming out before the solid stream.Quote:
Originally Posted by JKR06
I will try that next time. Thanks.
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Here is that picture of a plastic bait that you been trying to shoot the baby shed this is using MF floating plastic.Quote:
Originally Posted by JKR06
Attachment 258807
I am still getting some bubbles :(. It like at least in 2-3 baits per 10. They are getting smaller though so maybe I'm slowly getting there.
are you just shooting 1 mold? if so, do the upside down injector purge, and when you inject, SLOW and easy. if you push too hard, you will create turbulence that can leave bubbles. make sure your injector is full...if shootin one mold i will assume there would be enough plastic in a 4oz injector to fill it. the injectors have a "sweet spot". you purge the air, shoot what you can...but the last bit of plastic will have air in it as well. you want to shoot with the "middle" of your injector load, not the ends...if that makes sense.
i think this one has got us all to start, bob. we should start some kind of a support group or somethingQuote:
Originally Posted by snake River
Yes, just 1 mold. So once I fill the injector turn it upside down then right side up squirt a little out to get solid plastic going then squirt into the injector?
no no, you squirt some out with it upside down at a 45. when you see a solid stream which should come soon, like in the first inch or so of pushing, then flip it over and shoot.
That sounds like a good idea this is the perfect place to discuss our different issues with our problems that we are having shooting plastic.Quote:
Originally Posted by H2oHammer
it seems like when I got the baby Shad mold that I was having problems with the one of them was that the mold was too cold but I do not have any issues with that mold anymore matter-of-fact I wish I had to three more of them I had brick building the 40 cavity may be shed stinger I wish I would have kept that mold but I sold it at particular plastic bait is still very popular I don't know how many hundreds of them that I have made up but a lot of them keep working with it you'll get there sooner or later.Quote:
Originally Posted by JKR06