Pam asked me to come in and respond to this because I have been using Mol d'Art melters at my business for 4 years.
First, don't let the lightweightness deter you. I love how light mine are because we can move them around the kitchen as needed, and I have never had a problem keeping the outside clean and scratch free. The plastic is very durable. I have run two of my melters literally 24/7 for 4 years. Recently the thermostat on one of them went (no surprise, things do wear out), and it took two weeks to ship to Belgium for repair and back, and in the meantime my supplier had a loaner for me, so it was no skin off my back. The customer service from Mol d"art was excellent - my supplier brokered the repair, but Mol d"art contacted me to see what the problem was and fixed it!
I am going to speak in Celsius, because that is what the melters are and what I know. Anytime you heat chocolate past 40C, you get rid of every Beta Crystal. They DO NOT EXIST in any usable form after 40C. So you need either seed or movement to bring them into being. If you do not want to spend hours stirring, you NEED to seed your chocolate. If you are dealing with Tom from TCF, here are instructions that I SENT HIM to pass onto his customers. Clearly, he's not doing that :)
Here are the instructions that have gotten me through 4 years of business:
The basic formula for seed tempering dark chocolate is this:
The melter melts out the chocolate at 45 overnight. When you are ready to temper and work you turn the melter down to 35 and seed with 20% of solid tempered chocolate by volume - chips or pistoles are best. Over the next twenty or so minutes you stir the chocolate frequently and the temper should come in nicely. You may need a few adjustments, with a heat gun if it is too cold or another handful of seed if it is too hot, but this should take mere minutes.
It is important that the user know how much seed is 20%, so they should scale what they put into their melter before use.
Now, with any tempering machine or melter, time, temperature and movement are of the essence, but no formula accounts for environmental conditions - so it is important to use a piece of parchment paper to test for readiness of the chocolate before proceeding with production. Provided the chocolate is frequently stirred, you should be able to maintain temper for a very long time. We have used our kilo melter from maximum capacity to nearly empty over a period of ten hours with attention and stirring.
The key to use of the Moldart is that like any tempering machine, the user must be vigilant to maintain temper within the conditions of the room. The ONLY difference between a melter and a tempering machine is that the moldart melter requires the user to stir the chocolate, while a tempering machine does it for you. It is still up to the user to observe the results and manage the temper of the chocolate.
I hope this helps!