20kg DIY Chocolate Melter for about $200?
Melting chocolate is a challenge that many chocolate makers face and having a supply of melted chocolate on hand - at a known and precise temperature - is very handy.
The fastest way to do this is to use a special-purpose chocolate melter. These can cost tens of thousands of dollars. Less expensive is to use warming (or bread proofing) cabinets (without the water, of course). While these can be found used on eBay and elsewhere, new ones will set you back a thousand dollars or more and they are the size of a large speed rack - and not all kitchens have that amount of space.
Tabletop melters like the ones from Mol d'Art and Bakon tend to be comparatively expensive (a 20kg machine can easily cost close to $1000), but many people like the table-top form factor. I do, too, in part because you can mix and match pan sizes. Full, half, thirds - depending on the amount of chocolate you need to work with.
There are lots of DIY solutions, but not a whole lot that require zero construction.
A while ago, ChocolateLife member Ben Rasmussen, the founder of Potomac Chocolate, pointed me to an inexpensive buffet warmer from APW Wyott (link is to WebRestaurantStore where they are priced at $99) that he was using as a chocolate melter. I recommended this to someone else, but even on the lowest setting, they were finding that the warmer was scorching their chocolate. This is because the temperature dial isn't calibrated in degrees - it just runs from 1-10 - and, food warmers are typically designed to keep food at a minimum of 140F for food safety reasons.
NOTE: It's important that you get a unit that is designed to be used without water. Not all of them are. There are less expensive warmers than these but, as near as I can tell, they require water to work.
To combat the problem of overheating and scorching - and to provide a true temperature control - what's needed is an inexpensive sous-vide controller. (There are other temperature controllers, but you want one that's designed to work with food.) There's one on Amazon from a company called DorkFood for $99. The DorkFood sous vide controller has a range of 32F-200F with a precision of +/- 0.25 degrees.
Your "work" will be to find the maximum heat setting for the warmer that heats the chocolate without overheating and scorching it. Put the chocolate in the warmer, plug the warmer into the sous vide controller, and plug the sous vide controller into the wall, and set the temperature you are looking for.
Which means you might also be able to use the combination as a replacement for a Mol d'Art melter.
If you are having problems with the lower settings of the melter being too high, you may want to look into some sort of thermal mass (or, you could contact the manufacturer and ask). A Fibrament (or similar) baking stone will even out the heat. This may limit you to using shallower pans in the melter. Note - the smallest rectangular stone from Fibrament is bigger than the interior dimensions of the melter. Fibrament will cut to fit if you send them the dimensions with your order.
The nice thing about the sous vide controller is that it could have other applications for controlling temperature around the kitchen.