Keeping Plastic Clear Thru A Few Heat Cycles

[Ed_White]

I'm looking for a little advice to help keep my plastic clear thru a few heat cycles, my current process is this:

1 cup Lurecraft Med-Hard Injectasol and a smidge of hardener in a 2 cup pyrex, heated in a micro and stirred several times till it turns. While that is going on, I install 2 lead/hook inserts into a 2 cavity mold. Once the plastic is ready (330 or so), I inject the mold and set it aside to cool. Once I open the mold and trim away the extra bits from the baits, these bits go back into the pyrex (which has been cooling while I wait), and back into the micro it goes to be heated again. The plastic gradually yellows till it's amber for the last shot, which is the last of the plastic, usually the 6th shot. If the plastic has been colored, there's no issue, but my favorite pattern is a clear bait with a few things added later.

Any thoughts? Am I doing something stupid?

[alsworms]

Hi Ed,

 

If you aren't careful, ANY plastic will burn after several re-heats.  I'd try adding some heat stabilizer to your plastic before cooking.  Most places who sell the plastic also offer stabilizer.  The stuff is expensive, but well worth it.  Just remember a little goes a long way.  I used about 1 ounce in a gallon of plastic. 

 

Good luck!

[DAWG1419]

When I use a micro after 2/3 heat ups i dont really need to heat again. Just leave it in the micro after you inject left over back in the cup

[Saugerman]

What alworms said, you need to add stabilizer after heat ups .Any  plastic will yellow over time and again heat up., Stabilizer will help keep it clearer.

[Bass-Boys]

use stabilizer and only heat up enough plastic to do 4 shots not 6 ,,

 takes more batches but they will stay more clear.

[Ed_White]

Thanks for the quick replies guys, sounds like the heat stabilizer is a good start, and yeah, smaller batches so that it is used before it turns yellow sounds like good common sense, I should have thought of that.

Thanks All. 

[CNC Molds N Stuff]

Or more molds....  

[Lonestarbaitcompany]

Try covering your Pyrex cup with a potholder to keep the heat in. If you work quicker on the first batch you maybe able to do more then one pour before it cools off. I try to do larger amounts when possible because the heat holds longer and you can reheat less even though you have more plastic.

[mark poulson]

I find that, for me, NorPro silicone cups hold the heat a little longer, especially if you pinch the mouth shut with a big chip clip to form a small pour spout.

Google norpro silicone measuring cups and you'll find a bunch of choices

[Ed_White]

All good ideas, I do have 2 of these molds, covering the cup is another common sense idea I should have thought of, and the silicone cups sound pretty cool. Are they easy to clean?

[alsworms]

Or more molds....  

Yup......there's always that!  More money, but hey......in the long run, you'll be much happier.

[CNC FREAK]

i use a digital microwave 800Watts, i heat up the plastic combining full power with 30% power

plastic is cristal clear without stirring (only shaking the cup a few times)

i reheat on 10% power, works perfect to me
i think some microwaves have a program that is perfect to keep it just hot enough and dont overheat 

 

[Mudd Butt Baits]

I pour at 345-350, I have not had the clear change colors yet.  I have heated the cut off and bad pours well over 10 times, but I don't let it cool below 300 or so before reheating it.