Yellowing Plastic?

[mark poulson]

I have only been pouring a short time, so, if this is a dumb question, please don't be too hard on me.

I have been pouring flick shake worms and Ikas, typically using salt and softner in equal amounts, and heating my plastic to 360+- in the micro.

I hand pour and inject.

I decided to pour some Ika bodies with no salt.

I heated 5oz of plastic to 360, stirring it several times during the heating, and the plastic had a slight yellowish tinge.

Not the heavy brownish yellow from overheating (yes, I've done that), but enough so the Ika bodies aren't true clear.

I stirred in my flake after heating the plastic, so as not to have it color the plastic.

Am I doing something wrong?

Did the salt I used every time before disguise the yellow?

[Richard Prager]

I have only been pouring a short time, so, if this is a dumb question, please don't be too hard on me.

I have been pouring flick shake worms and Ikas, typically using salt and softner in equal amounts, and heating my plastic to 360+- in the micro.

I hand pour and inject.

I decided to pour some Ika bodies with no salt.

I heated 5oz of plastic to 360, stirring it several times during the heating, and the plastic had a slight yellowish tinge.

Not the heavy brownish yellow from overheating (yes, I've done that), but enough so the Ika bodies aren't true clear.

I stirred in my flake after heating the plastic, so as not to have it color the plastic.

Am I doing something wrong?

Did the salt I used every time before disguise the yellow?

When you are using less salt, it takes less heat to get to the same pourable (viscosity) state you were achieving with the more salted formula. Sounds like you scorched it a bit. You might try heating it a little slower. Was the plastic off color before you added the flake?

[powerworm]

from time to time over the years there has been a yellowing of the heat stabilizer thats used in all plastisols you may have gotten some of that as well. but if you arent making clear baits once you add the colorant you will never know it. also you dont need to heat your plastic up tquite that hot with or without salt!!

[Frank]

Clear baits can be tricky at times. All of the above is good advice but in my opinion you heated it to much to fast. For clear baits I have had best results making small batches and keep the heat below 340. And try and not heat to many times cause it slowly yellows. Bear has a plastic that has a high tollerance for heat and stays clear longer. Cant remember with one but it puts out some very water clear baits. Frank

[mark poulson]

Thanks to all for the help. I'll try smaller batches and less heat.

[mark poulson]

Thanks to all for the help. I'll try smaller batches and less heat.

I found I made two critical errors.

First, I used the last of the plastic in a gallon jug, and evidently I had not shaken the gallon enough while I was using it, so the stuff at the bottom was really thick, and yellowed easily. That stuff went into the round file.

Second, I was heating it too high.

I used 4 oz. of plastic from a new gallon, well shaken, 1 1/2 oz of softner (I like my Ika bodies soft), and a pinch of heat stabilizer, and only heated it to 350 degrees.

The baits came out great.

Thanks for all the help.

Edited September 1, 2010 by mark poulson