i’m serching for replacement desicant for my CFS because sometimes it goes up to 39% RH.
The problem is i didn’t find original replacement calcium carbide desicant.
Maybe i oversee it on Creality store.
So where i can buy new desicant?
There are printable baskets so you can put silca inside. For a couple of years i use some bags from a local shop the can really make the humidity going away in a hour from 35% to 15%, the work for 2 months. I tape a bag on the lid of the cfs. When the bag is hard it wont work anymore. I have printed some other solutions but the bags are stil the best for me. 500 gram silca wont do the same i have tested that one bag is 100gram.
The original calcium carbide packs are lasting now for 7-8 months, i don’t think silica will last that long. Ok plus point for silica is that its dryable.
The fact that silica gel is dryable is a big plus. You can use it over and over again. The calium packs are once usable. Also the silica gel indicates itself when it is saturated. It goed from orange/yellow to dark blue. If it is dark blue then regenerate it in your oven.
I got my CFS/K2 back in Feb this year and didn’t look too hard at the CFS humidity levels until some few months later and given it was around 50% decided to explore the situation. What I found was the desiccant bags had plastic around them. On removing the plastic covering I noticed that one of the bags was already hard and one was starting to get hard. With the plastic removed the humidity has come down to around 30% so it appears the supplied desiccant was already mostly spent.
What surprised me is that I’d take a half-used spool of filament out of an 18% RH CFS, seal it up in a Ziplock freezer bag with a pouch of fresh silica gel desiccant and a month later, when I open the Ziplock bag, the silica gel in the pouch is completely spent.
I figured the Ziplock bags would be a barrier to atmospheric moisture, but NOPE!
I suggest:
Forget the CFS desiccant. Model spool drier parts, print out and fill with desiccant. Works way better.
My desiccant holders take exactly 50 grams of desiccant. I used to weigh out but don’t anymore. Add a roll of filament? Add new desiccant to holder. install in spool and off you go. Every time I load a new roll, I replace the desiccant. Humidity here is over 80%. Hose is 45%. CFS (2) are sub 20%. Works great, no hassles.
I use non-indicating desiccant to stay away from unnecessary chemicals. Its available on amazon.
Really easy solution and works great.
Crystal Kitty Litter is mostly silica gel. I put a soup can or similar sized tub of it in the filament storage boxes, along with a non-electric dial type humidity gauge. Occasionally the dessicant gets baked in the oven around 300F for a few hours, which is easiest if you use metal cans. I’ve been doing this since the Printrbot+ days so around 2012 or so.
I’m using the CFS guide levels, I use silica gel in printed spool holders and swap out/re-charge silica whenever it gets above 30%, I’m in an extremely humid city, often over 80% humidity
my only real advice is wait until you buy silica to know what size you are getting, a lot of the desiccant holders that can be printed have large holes that smaller silica gel can pass through.
fine mesh fruit bags from supermarkets also work (if only using static locations inside the CFS)
I have a couple of kgs of Sigel desiccant beads in my home shop I use for a compressed air desiccator system. I got my sister to whip up some cotton bags that fit inside the CFS desiccant compartment, added some beads and then got her to sew them shut. The filled bags go into the kitchen oven at 125ºC for 4 hours to dry out. I got four bags made up so can keep two of them as spare in an air tight container for immediate use when needed.
Chris.S_NZ - Good idea regarding re-using the silica gel packs that come with filament. I was a bit worried about whether the packaging material would withstand the 120ºC needed for regeneration but I just tested a couple out and they seem fine after 4 hours sta that temp. I’m now going to dry all my packs and use them as well.
depending on where you are in the world, you’ll likely be able to buy something either like:
or
you can find cheaper off other sites, this is just a good description of the product i’m using.
(I got tired of collecting and using the little packs that came in everything you buy from shops to keep food fresh)
I store my spools in a basic Sistema container when not in the CFS with a humidity sensor so colour change while not needed helps to see what volume of the product is left still absorbing moisture