Microwave or Hot Plate
Posted: Mon Jul 21, 2014 11:09 amOk Guys,
So, this is my question. When heating plastisol to achieve a cure-state temperature (approx 350 degrees F), which is the better method for heating. Is it a microwave set for low with the plastisol slowly heated in a pyrex pour cup, or is it a digitally controlled hot plate set at 350 degrees with an aluminum pan designed for pouring plastics? I have only used the microwave method, but I have found qualms with it. There are as follows: If you're pouring a plastic with multiple colors, and you're pouring the plastic into a small mold with one (or maybe several cavities) you have to keep the plastic in a liquid state. Sometimes it takes the plastic in the molds several minutes to cool to the point that you can extract it and toss it into some cool water. In the meantime, your plastic in the pyrex cups is cooling/curing/solidifying. So when you're ready for your next pour, you have to reheat the plastic in the microwave. You have to watch it very carefully, otherwise it will scorch, yellow, and STINK! This smell follows the plastic after it's cured. I've noticed the continuous heating, curing, heating, and curing eventually change the properties of the plastic to the point that it stiffens and eventually burns. This sucks when you've added dye to the plastic, because the color change is much harder to track. I use an infrared heat thermometer to track the temperature. This has helped tremendously, but I still have issues. I've also noticed that when heating in the microwave, and stirring, thousands of air bubbles get trapped in the plastic. This even happens when I stir it very slowly and avoid whipping it. These little air bubbles will transfer to your final product. You can't really notice them unless you stretch the plastic out. When stretched and elongated, the air bubbles become more visible. This doesn't really bother me as it's just aesthetic. I'm sure I could keep the plastic in a liquefied state much longer if I had more volume of plastic in my pyrex cup, but I don't usually pour a massive amount of plastic at one time. I just don't see the point in using more that you need, even though you can save the leftover and chop it up for remelting.
So, I've never tried this, but they have induction hot plates (the New Wave Induction Cooktop) that are digitally controlled to hit and hold a specified temperature. I'm thinking it would be better to use this cooktop in conjunction with the aluminum pots to pour my plastics. That way the plastic can stay at a specified temperature, in a liquid (pre-cured) state. It will always be ready to pour, and it will always be at the set temperature. Now, as I stated, I have never tried this. I have heard stories about the plastic scorching using this method, even when the hot plate is set for the correct temperature. But I'm wondering if the attempts people have made regarding this method was with a mechanical thermometer, or a digital thermometer on the cooktop? When I watch the infomercial for the New Wave, it utilizes "induction heat". This means that only the place on the cooktop where metal (your pot) comes into contact is where heat will be transferred. If this is the case, you should be able to fit 2 or 3 small aluminum vessels onto the cooktop at once, and only the surface area under the vessels will heat (and I'm talking about vessels like aluminum cups used for frothing up milk on a cappuccino). I'm also curious if the "bubbling effect" occurs when the plastic is heated in a pan on a cook top like it does in the microwave. The New Wave is supposed to be VERY accurate with it's temperature controls. That being the case, do you still think the plastic would scorch? If the cure temp is 350 degrees, and the cook top doesn't exceed that, why would the plastic scorch? It doesn't scorch at 350 degrees in the microwave.
Just looking for some feedback on this. Has anyone tried heating plastic using the New Wave cooktop? Just looking for your $.02 . Thanks.
So, this is my question. When heating plastisol to achieve a cure-state temperature (approx 350 degrees F), which is the better method for heating. Is it a microwave set for low with the plastisol slowly heated in a pyrex pour cup, or is it a digitally controlled hot plate set at 350 degrees with an aluminum pan designed for pouring plastics? I have only used the microwave method, but I have found qualms with it. There are as follows: If you're pouring a plastic with multiple colors, and you're pouring the plastic into a small mold with one (or maybe several cavities) you have to keep the plastic in a liquid state. Sometimes it takes the plastic in the molds several minutes to cool to the point that you can extract it and toss it into some cool water. In the meantime, your plastic in the pyrex cups is cooling/curing/solidifying. So when you're ready for your next pour, you have to reheat the plastic in the microwave. You have to watch it very carefully, otherwise it will scorch, yellow, and STINK! This smell follows the plastic after it's cured. I've noticed the continuous heating, curing, heating, and curing eventually change the properties of the plastic to the point that it stiffens and eventually burns. This sucks when you've added dye to the plastic, because the color change is much harder to track. I use an infrared heat thermometer to track the temperature. This has helped tremendously, but I still have issues. I've also noticed that when heating in the microwave, and stirring, thousands of air bubbles get trapped in the plastic. This even happens when I stir it very slowly and avoid whipping it. These little air bubbles will transfer to your final product. You can't really notice them unless you stretch the plastic out. When stretched and elongated, the air bubbles become more visible. This doesn't really bother me as it's just aesthetic. I'm sure I could keep the plastic in a liquefied state much longer if I had more volume of plastic in my pyrex cup, but I don't usually pour a massive amount of plastic at one time. I just don't see the point in using more that you need, even though you can save the leftover and chop it up for remelting.
So, I've never tried this, but they have induction hot plates (the New Wave Induction Cooktop) that are digitally controlled to hit and hold a specified temperature. I'm thinking it would be better to use this cooktop in conjunction with the aluminum pots to pour my plastics. That way the plastic can stay at a specified temperature, in a liquid (pre-cured) state. It will always be ready to pour, and it will always be at the set temperature. Now, as I stated, I have never tried this. I have heard stories about the plastic scorching using this method, even when the hot plate is set for the correct temperature. But I'm wondering if the attempts people have made regarding this method was with a mechanical thermometer, or a digital thermometer on the cooktop? When I watch the infomercial for the New Wave, it utilizes "induction heat". This means that only the place on the cooktop where metal (your pot) comes into contact is where heat will be transferred. If this is the case, you should be able to fit 2 or 3 small aluminum vessels onto the cooktop at once, and only the surface area under the vessels will heat (and I'm talking about vessels like aluminum cups used for frothing up milk on a cappuccino). I'm also curious if the "bubbling effect" occurs when the plastic is heated in a pan on a cook top like it does in the microwave. The New Wave is supposed to be VERY accurate with it's temperature controls. That being the case, do you still think the plastic would scorch? If the cure temp is 350 degrees, and the cook top doesn't exceed that, why would the plastic scorch? It doesn't scorch at 350 degrees in the microwave.
Just looking for some feedback on this. Has anyone tried heating plastic using the New Wave cooktop? Just looking for your $.02 . Thanks.
