Today, I learned the hard way that the desiccant packets that come with CFS are not microwave-safe. My 3D printer was alarmingly showing 38% relative humidity inside one of the two CFS units, so I thought, “I’ll microwave the cloth desiccant packs and dry them out.” Twenty seconds later, I had two puddles of melted plastic.
Why they made something that people would need to periodically dry out with heat out of what is apparently a plastic-based fabric, I have no idea, but I’m now printing a desiccant box and will put bare desiccant in there as soon as it arrives tomorrow. Life’s too short to deal with nonsense like that.
The problem with microwave-drying desiccant is that there is too much energy in a typical microwave oven - a thousand watts or more - so the tiny beads heat up very quickly, leading to bag damage. Might work better at 10% power (for x10 duration) but even that is a gamble as microwave ovens heat unevenly.
Could place desiccant on a non-cooking tray in the oven, at lowest temp (slightly over 100degC would be ideal) for 8-12+ hours or so. If your oven only goes as low as 250degC, don’t try it, as some bags may begin decomposing or melt.
To get rid of unpleasant odors in either oven, insert a boiling-safe bowl of water with some white vinegar mixed in it. Get it hot to slightly-boiling, so that the vinegar vapors fill the oven. This itself smells kind-of awful; bear with it for a half-hour or so. Then leave open to dry. Give it the sniff-test the next-day; if needed, repeat.
Another option could be to place all of the desiccant into a vacuum chamber, preferably left in a warm spot. Remove the air, seal it off, let sit overnight. In the morning, pump off the released moisture and let it sit again. The warmer it is, the faster this will work. Slow process, but arguably more energy efficient, with zero chance of burning anything. Only problem is, who has one of these?
I chucked the Dessicant that came with the CFS and printed a refillable Dessicant box that holds 44grams of Dessicant beads. The current humidity in my CFS is 13% and it has been in there for a couple of weeks. If you have a filament dryer box, put the Dessicant in there for 12 hours at the temp for PETG and it will recharge your Dessicant beads
Any recommendations on a good replacement desiccant to get or are they all pretty much the same? Think I’ll go the route of printing a new refillable box for it as I can’t be bothered to dry out old stuff.
Yeah, drying desiccant requires a bit of care, I’ve even shattered porcelain “microwave-safe” bowls doing it wrong and I find that the colored desiccants tend to burn really easily, anything over 120°C (250°F) will burn the additives and possibly reduce the desiccants effectiveness. The bags are probably a synthetic fiber like polyester and you probably got them significantly hotter than that as polyester melts around 260°C (500°F).
My recipe is to cook on power level 3 for roughly 2 minutes to get the beads up to temp then on power level 2 for 5 minutes at a time until the beads return to a nice orange color. Stir or shake up the beads periodically to help release moisture.
I also tend to mix commercially available colored “Dry & Dry” brand orange beads with cheaper clear beads (the 100’s of included bags from various filaments or even silica “gel” cat litter) to have the benefits of both and to keep costs down. I’ve also tried “Wiseorb” and some other brands, but find their beads to be very inconsistent in size and some are too small and fall out of commonly used printed desiccant containers.