super tough plastisol always burns. Help

[Fern]

I have been using bait plastics 312 saltwater blend for a while now with no issues. Recently I switched over to their 362 and I find that the plastisol burns so much easier than the 312 ive used before. It either yellows badly or burns. I use the same 700 watt microwave and pour the plastisol in a 1 cup pyrex, hit 2 minutes, mix, heat 30 seconds, mix, heat 30 seconds, mix and repeat till the plastisol has become less viscous. When I use the 312, this works perfectly every time but with the 362, I keep getting yellowed plastic or burnt plastic. I mix the plastiol with a drill and mixer i got from baitplastics for about 2 minutes before heating. 

[basskat]

Do you check the temp? I'd really suggest that you check the temp and get it up to 350 and stop. Sounds like you're overheating by just looking at the plastic.

[Fern]

26 minutes ago, basskat said:

Do you check the temp? I'd really suggest that you check the temp and get it up to 350 and stop. Sounds like you're overheating by just looking at the plastic.

You are correct, I dont check the temp much, I just got use to working with 312 and getting it to temp correctly every time. The 362 stuff stays very viscous and thick and by the time its nice and liquid-y, I can already see yellowing. I guess I should re-invest in another thermometer (misplaced the last one and never replaced it). Question though, If it is past the 350 and its still thick, what causes this? shouldnt it be liquid if its at temp? 

[Bass-Boys]

I am not sure but I think the firmer the plastisol the thicker it will be at 350?

[Les Young]

How many ounces are you heating at one time? Maybe i've just been lucky, but i haven't burnt any of medium  or the hard either one.

Edited September 9, 2021 by Les Young

[Travis]

Seams many times the answer is just to stir more frequently and shorten heating times between the mixing until you dial the method down.

Material viscosity and density play a roll in heating via microwave.  Viscosity will determine how heat flow by convection through the product.  Very likely getting hot spots in the thicker plastic you are trying to use now.   Microwaves can also overlap and effectively cancel each other creating cold zones (likely worse in older or cheap microwaves), thus the easy solution of rotation of the product to try and minimize the occurrence.   Between the two can really create some issues if you don't mix.

Some products are just perform better heated in microwaves than others from my past experiences but haven't bought any new plastic in many years as still have a few gallons of Calhoun's to use.

[McLuvin175]

The other thing to consider is the harder the formula the thicker it will be when hot. If you try heating to get the same viscosity as a softer formula you can run the risk of overheating.

[mark poulson]

Maybe try adding some heat stabilizer every time you cook a batch, or add some new to an existing batch.

[Fern]

On 9/8/2021 at 5:45 PM, Les Young said:

How many ounces are you heating at one time? Maybe i've just been lucky, but i haven't burnt any of medium  or the hard either one.

I heat a cup at a time. I never burn the medium(262) or the saltwater(312), it only ever burns when i heat the super tough (362). 

[Les Young]

I'd say Bassboys & McLuvin are right. Makes  to me that thicker material would burn when we'd normally be  pretty much expecting the same pourable consistency when infact it probably never will get as thin as the other,

[Bass-Boys]

Needs to get a thermometer , to see what temps it is getting to. then get back with us. Also contact Plastisol maker for recommendations on temp limits.