Dry & Dry desiccant lists the ideal drying procedure as 0.5-2 hours at 200-250F. Since the P1S bed can reach up to 100C (212F), could you conceivably dry silica gel beads on a 3D-printed sieve or something with the bed set to 100C for around 1.5 hours?
Conceivably yes. They probably won’t reach full dryness though. Silica gel beads are manufactured to capture and hold water. Getting that water out is harder and why the highish temperature is needed.
But that only matters if you need them really dry. When they cool down they’ll still be water getters. It’s just depending on how well they dry, they might not hold as much water before needing recharged again since they already may have some water, and they may not dry whatever you’re drying quite as much.
Those finer points may or may not be important depending on your intended usage.
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You can dry silica gel much faster. In a microwave.
How long does it take to dry it in the microwave?
Heating doesn’t take long apparently (I haven’t done it yet) but there is a risk with overheating which can damage beads and reduce effectiveness.
I dry smoker wood pellets in our microwave and I bet it’s somewhat similar. I heat them up and then spread them out on a screen so there’s air circulation to remove the water that comes off. With pellets it can be a lot and it even fogs my glasses. But as they start cooling where they can start reabsorbing that water, it’s either into sealed Mason jars or back into the microwave for a reheat. (This does wonders for keeping a pellet smoker running well on lower settings or if used in things like “The Amazin’ Smoker Tube”.
Like I said I haven’t done silica gel yet in the microwave but intend to. Be careful not to heat them too much at any one time. Put them in and let them rock and you may even get a fire. If they are like smoker pellets, you may need to heat, vent the water, heat again, repeat.
Best bet would be to search for how-to articles because I’m sure they’re out there.
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Is that food safe? I’m purposefully avoiding taking any filament into the kitchen to avoid microplastics and fumes. (If the silica gel doesn’t off-gas and only releases steam, I could see that being food safe.)
The instruction should be on the bag. Here’s what’s on mine, but read yours because the desiccants can be different.
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That’s a good question. I buy the orange colored silica gel off amazon and they say you can dry them in the microwave on the defrost setting for 10 minutes. I tried it but it took 25min for the batch I but in there to fully dry and I noticed I bunch of them had split open. The next batch I put in my old toaster oven in the garage and that was much better. It’s like 200F for 45 minutes or something like that. I didn’t notices any cracked ones either.
That’s a good idea, we just ditched our old toaster oven 2 months back. makes me wonder though if it isn’t cheaper to just buy more beads instead of going to all the trouble and expense. I know it sounds wasteful, but considering the low costs?
Thank you! I had forgotten to mention the big one with a microwave - don’t ever heat the blue silica gel beads. The blue is a cobalt compound and toxic. The other colors are supposedly less toxic. Best would be the no-indicator beads and even better would be not to use a microwave used for food.
Added - just saw @DWdesigns food grade label.
Yes, I got that specifically for this concern. Oven or microwave, foods go there, too.
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I dry all my beads in the microwave. I use 1 minute 45 secs on defrost and they are generally back to a low amount of moisture. I’m sure I can dry them further, but I don’t find I need to. 2 minutes in a microwave sure beats hours in the filament dryer or on the bed. And honestly, I’ve never been able to duplicate the microwave drying efficiency in the filament dryer.
Things to watch out for:
- They get really hot and will melt most plastics so be careful what you use to hold them. I like silicone, but paper plates will hold up to the 1:45 cycle.
- Use defrost because most microwaves can’t limit their output very well. The defrost cycle is generally a certain amount of time with the power on and then a certain amount of time with it off. This is good to stop the pellets from overheating or melting things around them.
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How do you get them dry in such a short amount of time? When I tried the microwave, 10 minutes defrost only got the top layer dry. Maybe I was drying too many at a time?
Microwave and beads works but one should know what to do…
For starters use two large enough and HEAT resistant jars, glasses, what is required for your amounts.
Pre-heat them by rinsing with boiling water or placing in the oven at about 60-80 degrees Celsius - this will prevent moisture from condensating later which makes the beads stick to the walls…
Fill one jar with the beads, then place both in the microwave.
Set the timer for 5 minutes, full power and stop things after 30 seconds.
Slowly drain the beads from one jar to the other - you shall see a bit of steam escaping on a cold day.
Back inside and continue for another 30 seconds.
Repeat a few times.
Once you feel those jars getting a bit too hot for comfort grab something to protect your hands and continue in 10 sec intervals while letting the beads cool down a bit before going back in.
Unless soaked three to four rounds do the trick.
I started with a scale to see when there is no further reduction but now use indicating beads instead that I mixed in.
Once they go blue again I know all beads are dried out.
Cover with a paper towel or such and let cool down to room temp, the cover helps to keep the moisture from the air out while the beads are still warm enough.
Do yourself a huge favour and don’t rush thing in the microwave!
If you think those beads are bad when spilled onto a hard floor…
It takes a bit to turn water into steam but once those beads get too hot and can’t hold it any long they tend to go boom.
Let this happen in the microwave and you lost the beads while trying hard to clean out this fine mess without making more mess.
Have them go very close this point and they might pop while you drain them over or just handle the jar.
Happened to me only once when I got distracted by a phone call, trust me it won’t happen again as it was a rather painful experience.
If you happen to have an inverter microwave you use a lower power.
Normal ones are horse manure here as they still just go bang bang.
I had good results starting with about 30 sec on full power to heat the beads to then continue on just 300W for 12 minutes.
Quite nice if you are lazy as you can get away without the decanting back and forth to drive the moisture out.
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I do 50% power for about 5 min in my little 700w microwave… depends also on how much you do at once.
IMHO, it’s much safer than popcorn with butter. You won’t eat silica gel.
I’m sure I can go longer with them but a “normal” batch for me is about a 80 ml level of beads. I normally do it with the Polymaker beads from their dryers and they indicate very well. When they come out of the microwave they are nice and bright orange again (once they cool down). They do show a 10% rating alone in the PolyDryer with no filament, so I’m sure I could go longer and get them down to around 5%, but its not worth it.