The Hunt For Big Fish with Larry Dahlberg

Larry,
How many times can you re-melt Alumisol before you need to add heat stabilizer? I'm hoping it's more than just a couple. How do you know when you need to add it? Does the Alumisol stop melting and getting viscous? Thanks in advance for the response.

Scott

You could melt it dozens of times without it, but using it results in a bit less smoke and loss of plasticizer. It also depends on how "hard" the plastisol mix was to begin with. the harder the mix, the sooner you will use a little stabilizer. It also depends how long you have you plastic "cooking". In the old days before microwaves, and also today with larger batches, if you have your molten plastic sitting in a hot pot in a ready to pour state, it will be more likely to need stabilizer when reheated.
When I'm pouring quart batches, and say making a half dozen 10" whiggleys and using only one mold, due to cooling time in the mold I'd have to reheat my plastic six times. Unless I accidentally got it too hot (notice yellowing if clear) and it really smoked on one of the reheats, I would not bother with stabilizer.
So, in a nut shell it's really not necessary, but provides some insurance to prevent the material from smoking or actually combusting and turning into a foaming black blob and billowing sooty black smoke.
It helps a great deal to "get to know" both the microwave and the container in terms of how often you need to stir your plastic and how various power settings affect how quickly and evenly the plastic heats up in the container. I suggest stirring often. All containers have hot and cold spots. usually the larger the container and thicker the glass the more likely hot and cold spots will occur. When reheating plastic and you get thick glob surrounded by thin material, stir it until it averages out in its thickness. Actually, that's the best defense against burning and overheating.
Hope I've not made it seem too complicated, because it's not! Good question though, thanks!
best
L

Hello I'm new to this and was wondering what the heat stabilizer does to the plastic.
Does it -
~ make plastic softer
~ lessen the strength of plastic
~ lengthen cure time
Also how much stabilizer is ended for a given amount of plastic?
Any info would be appreciated.
Thanks.

It makes it less likely to smoke and burn, especially after it's been reheated. A cap full in a quart is about right. It is not a critical part of the process, and not a necessary ingredient by any means.
best
L