Are we kidding ourselves about desiccant?
I'm sure many do what I do- dry filament and put it in a zip-lock bag with a moderate size silica gel desiccant pack. Hopefully a pack that was recently dried, but I admit to not doing that as often as I should. I do keep them with indicators, so I know if there's a significant problem.
But thinking about it, I'm putting 1 kg of freshly dried filament with a large surface area in a bag with a small bag of gel that might or might not be as dry as the filament. Is the desiccant really buying anything or would it be better to just bag the filament, squeeze out as much air as possible and call it a day?
RE: Are we kidding ourselves about desiccant?
I'm sure many do what I do- dry filament and put it in a zip-lock bag with a moderate size silica gel desiccant pack. Hopefully a pack that was recently dried, but I admit to not doing that as often as I should. I do keep them with indicators, so I know if there's a significant problem.
But thinking about it, I'm putting 1 kg of freshly dried filament with a large surface area in a bag with a small bag of gel that might or might not be as dry as the filament. Is the desiccant really buying anything or would it be better to just bag the filament, squeeze out as much air as possible and call it a day?
I found with plastic bags that over time they can get scratched or torn and will no longer be air-tight. I keep all of my hydroscopic filaments in Polymaker dry boxes with 2 desiccant chambers filled with activated alumina. For the nylon (PA), PC and TPU I'll put it in the dryer before a print even if stored in a dry box.
RE: Are we kidding ourselves about desiccant?
The easy solution is to dry the dessicant too of course. Although the ziploc bag itself isn't particularly moisture tight either.
I store my filaments in an old paint bucket with a layer of oven dried rice on the bottom as dessicant.
RE: Are we kidding ourselves about desiccant?
Type of desiccant is critical. Most colour changing desiccant is already too wet to do much good when it starts to change. I have a couple of kgs that I quit using once I found activated alumina.
I store all my filament in storage bins with at least a kg of desiccant, with temp and RH% indicators. I am lucky where I live since it is normally dry so this works for me. A friend of mine has individual commercial boxes with desiccant and indicators for every spool. Once it comes out of the dryer, it goes in the box, only to be removed when empty. I do have a dry box for feeding filaments that absorb moisture quickly like TPU.
In my search, I tried vacuum bags and zip lock bags. Best bags were the ones that the filament came in. I still find storage bins are the best option since they are easy to stack and work with. Support 1 or 2kg spools. Problem with vacuum bags is if they leak, they bring the moist air into the bag.
Silica gel desiccant is easy to damage if you over heat it. I also found some would break when removing and returning to the storage containers. I use soup infusers for storing my activated alumina and can just put them in the oven to dry. No handling little bead that can get everywhere.
With this setup, I can usually go 4 to 6 months without having to reactivate the desiccant.
To answer the question about fooling ourselves, I don't think so. Keeping filament dry is easier than having to wait 8 hrs to make a print as your filament is in the dryer.
I have been thinking about spools with solid sides vs perforated sides when in the dryer. How well can you dry the middle of the spool?
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...spools with solid sides vs perforated sides when in the dryer. How well can you dry the middle of the spool?
That's actually why I believe it matters printing from a drier (not "dry box") to give the outer layer - possibly even the unrolled filament - a few precious minutes of "VIP" drying. One observation to confirm this: I sometimes see broken ASA filament with this process at 69°C (which is as hot as the spools of the brand will permit without excessive warping) because it gets brittle when it's "very" dry. This is not common if I dry the whole spool - even for much longer - at the same temperature, then use it for printing later.
Of course, people use dry boxes successfully - if it works, it works. All I'm saying is that I believe I see a difference.
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The more I read, it seems silica gel isn't a great choice for RH below about 30%, which is, IMO, too high for filament. I have a pound of 4A molecular sieve in a can somewhere from another long-forgotten project, and a small kiln I can dry it in. I'm thinking that would be a far better choice than silica gel.
I've got some decent wireless sensors, and I'll start monitoring inside the bags to see what really happens.
RE: Are we kidding ourselves about desiccant?
@conrad-2, I had the same question and did a bunch of searching a while ago that I've lost the details from at this point. The layman's-non-technical memory I have of this were claims that equally dried desiccant and filament in a container (say both starting at 3% relative humidity) would interact with any water vapor that made it into the container differently, and that the desiccant has much more affinity for taking up water, so it would go there. Since this seemed to fit with my experience I left it there (and proceeded with that assumption).
So...I use an EDry cabinet to passively dry filament AND desiccant to 2-3% relative humidity (relatively slowly, a week or two, all new filament goes there first). I use color changing orange silica (I have a fair amount of activated alumina as well but haven't needed to switch to it). Then filament goes into those oh-so-common Rubbermaid 21 Cup Container dry boxes and I print from those. These boxes with one of my (very dried) desiccant containers maintain at least less than 10% relative humidity for extended periods. If/when the desiccant begins to change color, or when I'm printing that filament, I swap the desiccant (in seconds) for a fresh (dried) one from the dispenser in the cabinet. "On deck" filament goes in EIBOS vacuum bags, which are the bags I've found that are durable and entirely reliable (remain vacuum packed essentially indefinitely), again with one of my dry desiccant containers inside. Filament that is particularly hygroscopic might be rotated back through the EDry periodically when there are open spots (the humidity indicators suggest this isn't necessary but it easy to do and...just feels right). The entire process has been working well for me for a couple years. Doing this (religiously, automatically with new filament) has dropped filament moisture as a variable entirely out of my printing (including any need to prepare a spool at the point when I want to use it), which I have throughly appreciated. (If something goes wrong, or I'm in a hurry with new filament, I can still run a spool through my old dehydrator for a couple hours...doesn't happen often.)
If this sounds interesting enough to see more, check out my video (just went up a few days ago), "No Wet Filament!" It's a bit of a general overview of why one might care, and then a tour of exactly how I manage this particular approach (with links and the like in the description of you're looking for more info.).
RE: Are we kidding ourselves about desiccant?
BarrittWorks
If this sounds interesting enough to see more, check out my video (just went up a few days ago), "No Wet Filament!" It's a bit of a general overview of why one might care, and then a tour of exactly how I manage this particular approach (with links and the like in the description of you're looking for more info.).
Thank you for the video. The EDry cabinet is very interesting. One is on my wish list. Small one was US$695 from one site. Had fitting to print directly from.
For his boxes, a friend of mine purchased sealed boxes from AliExpress for his filament. Very low cost Come with fittings, temp/RH gauge and bearings, in the same price range as what is in the video.
I like the card indicators instead of the meters. I have looked at card indicators and found that many only work a few times. If kept dry, they may last much longer. Using the EDray to dry the desiccant is a great idea and a much easier aspect. Silica will be wonderful in that area. I would like to see where he found silica that indicated for less than 10% RH at 22.
RE: Are we kidding ourselves about desiccant?
OK, here we go, my 5p.
I have a std Mk3 and a std Mk4. (also an AnyCubic resin and a small cheap HobbyKing filament printer I bought "to see if I'd like it". (Spoiler, I did)
I model N Gauge railways, fly RC models I make (mostly freestyle quadcopters now), and make parts for an after school club I run to get boys into engineering.
I have filament of all makes, dating back a decade or more, about 70 reels in various stages of use.
I do not use dessicant, I do not use an enclosure, some of the fliament is stored in its cardboard box without a plastic bag.
I'm in the often damp UK, and the filament and printers are in a room with two tropical fish tanks shedding humidity. (up to a year ago it was three tanks!). Also 8 house plants in damp soil, three of which are on a shelf almost over the filament printers.
When I want to use a specific colour reel, I break off approx 70mm lengths. Initially they snap, but reaching the end of the "contaminated" section after a few tries the filament bends not breaks. I then trim and use.
Yesterday I used a reel of (purple) ESun PLA for the first time in seven plus years. It had been in its box with an unsealed plastic bag, no dessicant. It took about 250mm of snapped off sections before it bent, thats about the most I have ever had to remove unused. Trimmed and used on the Mk4. It printed first time perfectly.
I then printed the same part in some budget HobbyKing dark green PLA. Only needed two break sections, printed perfectly. That reel was in its box without a bag, and is at least a couple of years older than the purple.
I use default PrusaSlicer settings for PLA on the Mk4. (On the Mk3 I usually have to increase the bed temp by 5C above PLA default, and it needs more careful bed prep (cleaning).
Ages ago (pre COVID) I bought an Sunlu reel heater/dryer enclosure, used once to prove it wasn't faulty on supply, since then sat collecting dust.
I do print less frequently with PETG, ABS, and reasonably frequently in TPU. Those reels are stored in an old sideboard in another room near a radiator, otherwise they get no special treatment, and some of them are in boxes with no bag. A reel can sit on top of the printer for a week or more between jobs to no ill effect.
SO, are we kidding ourselves about dessicant? YMMV, though in my case, and don't ask why I get the results I do as I don't know, I'd say yes.
RE: Are we kidding ourselves about desiccant?
Bad Raven you are going to catch H*** for that sacrilegious post! But not from me, I agree with everything you said. I've been into 3D printing since 2011 and have never had a problem with any of my filaments just sitting out. Today I use primarily a Prusa Mk3S+ that I built 3.5 years ago. It has worked flawlessly and I have never had a failed print with that printer. I use PETG for almost all my prints. Once I load a spool of filament on the printer it usually just stays there until I use it up or I need to change color. I sometimes go several weeks between prints and that PETG will just stay on the printer. I have a cheap hygrometer next to my printer and last time I looked it was indicating about 60% humidity level in my basement shop. Yes, I get a little bit of oozing from the nozzle while the printer is coming up to printing temps but I simply wipe it off right before the print head starts moving. Again, never had a failed print with the MK3. I did buy a large food dehydrator several years ago to use as a filament dryer. Used it one time to see if it worked. Couldn't tell any difference so today I only use that dryer to cure paint on models I'm making. If I do have to put a partial spool into storage I do put it back in a plastic bag with a small pouch or two of desiccant, if I remembered to save them. I have always wondered about all the hype and hoopla over drying filament.
And to add more fuel to the fire, my Prusa printer sits in the open on a cheap $46 plastic folding table. Only thing else on the table is the aforementioned food dehydrator. Far from being the most rock solid stable surface that everyone talks about needing. Has worked very well for me.
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@zab, @bad raven: Obviously you guys don’t print PA, PC or TPU. Even in a moderately dry climate you cannot print them if they haven’t been stored properly and/or dried first. If you only print PETG or PLA then maybe you don’t need dry boxes or a drier. I generally leave my PLA spools out. Over time though they do get brittle.
RE: Are we kidding ourselves about desiccant?
Please re-read my post, I do use quite a lot of TPU, and state there how simplisticly I store it. No I have not printed PA or PC, not had a need.
What I find interesting is that the normal budget basement PLA goes brittle almost measurably linear length to time unused, working from the cut end, so the longer the unused time, the more I have to break off.
@zab, @bad raven: Obviously you guys don’t print PA, PC or TPU. Even in a moderately dry climate you cannot print them if they haven’t been stored properly and/or dried first. If you only print PETG or PLA then maybe you don’t need dry boxes or a drier. I generally leave my PLA spools out. Over time though they do get brittle.
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Please re-read my post, I do use quite a lot of TPU, and state there how simplisticly I store it. No I have not printed PA or PC, not had a need.
What I find interesting is that the normal budget basement PLA goes brittle almost measurably linear length to time unused, working from the cut end, so the longer the unused time, the more I have to break off.
@zab, @bad raven: Obviously you guys don’t print PA, PC or TPU. Even in a moderately dry climate you cannot print them if they haven’t been stored properly and/or dried first. If you only print PETG or PLA then maybe you don’t need dry boxes or a drier. I generally leave my PLA spools out. Over time though they do get brittle.
Sorry didn’t see that bit.
I live in a much drier climate and store TPU in a dry box with activated alumina desiccant. Especially for the foaming TPU’s even then it has to go in a drier to get a decent outcome.
With regard to how filaments are packaged by the vendor, here is an interesting example. It’s a brand new unopened roll of Prusament PC-CF that was pulled from a vacuum sealed bag with desiccant only 3 months after manufacture and printed immediately. The results were less than ideal. Then the same print after drying for 8 hrs. I think the point being that desiccant and storage is import but only for hydroscopic filaments and that you can’t assume that vendor sealed packaging is immediately printable.
RE: Are we kidding ourselves about desiccant?
I find @bad-raven-2 comments about length and brittleness interesting. Things like electrical coax cable will go bad from the ends due to moisture, but I don't see any similar mechanism that would apply to filament. My basement stays at about 40% due to a dehumidifier in warmer weather and I don't find much need to dry PLA or PETG, but I do anyway. 😀
RE: Are we kidding ourselves about desiccant?
I find @bad-raven-2 comments about length and brittleness interesting. Things like electrical coax cable will go bad from the ends due to moisture, but I don't see any similar mechanism that would apply to filament. My basement stays at about 40% due to a dehumidifier in warmer weather and I don't find much need to dry PLA or PETG, but I do anyway. 😀
I remember a Voidstar Labs YouTube where if you tuck the end of PLA into the holes on the side of the spool, it will cause it to become brittle. I need to find this video because it's weird if true.
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Fast forward to 9:30
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This is 100% the case. I have several filaments that just break off on the roll doing that. It's especially bad with transparent PLA.
I use just some 20 gallon totes to store rolls in. Which is a problem, because they are out of stock and I need a new one... (I want em to match or it wont look right) With whatever desicant I have on hand and a dehydrator if need be.
I find @bad-raven-2 comments about length and brittleness interesting. Things like electrical coax cable will go bad from the ends due to moisture, but I don't see any similar mechanism that would apply to filament. My basement stays at about 40% due to a dehumidifier in warmer weather and I don't find much need to dry PLA or PETG, but I do anyway. 😀
I remember a Voidstar Labs YouTube where if you tuck the end of PLA into the holes on the side of the spool, it will cause it to become brittle. I need to find this video because it's weird if true.
Vehemently against AI. I've seen that film. It ends badly.
RE: Are we kidding ourselves about desiccant?
I am brand new to all of this but is this a problem in dry climates? That we still need to use some kind of dessicant or silica?
RE: Are we kidding ourselves about desiccant?
I am brand new to all of this but is this a problem in dry climates? That we still need to use some kind of dessicant or silica?
Depends on the material. Example, nylons (PA6 especially) can become unprintable even after exposed to room ambient humidity for a few hours. I suppose if you lived in a dessert (< 15% RH) you don't need to worry about dry boxes