This is what the humidity is over a six month period we are now going into our wet season.
Nelspruit South Africa
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I do not totally agree with this. I had some old pla about 6 years old didnt care much for the color. I dried it in my drier for 3 days and then threw it in and it printed perfect. Before I dried it the filament would snap easily but after drying it didn’t have that issue.
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Seeing that you are based in London, I would advise at least a single low cost filament dryer.
Three main reasons:
- Moisture will not leave the filament without heat. Desiccant may reduce the water uptake rate, but it will not remove moisture from a filament. So you’ll want to be able rule out filament moisture as a cause for print failures which you can only do if you dry your filament. And you probably do not want to do that in your kitchen oven or occupying your printers heatbed.
- It is unfortunately common nowadays to get saturated filament straight from the bag. Bambu themselfes recommend drying after opening. After all, it is rare to know in which climatic conditions filaments were extruded, wound and stored prior to packaging. Chances are, that does not happen in a dry-room.
- I do indeed remember nice and warm summer periods from my London period. All the more cherished for all the fog, drizzle, sprinkle, rain, sleet, downpours and deluges
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Get a gasketted airtight bin from Amazon or Costco. iris makes some good ones for like 20 bucks. You’re good to go. If you want to be sure just add a rechargeable silica gel thingy from Amazon.
could somebody recommend a good airtight box from amazon.co.uk ? There are loads of plastic boxes, but in my experience they’re rairly airtight :-/
Look for plastic boxes with a rubber seal in the lid.
A 20-pack of filament vacuum bags with a hand pump + desiccant bags you toss in are less than 20 USD/EUR on Amazon or less than ten USD/EUR on Ali. I just dry my spools and put them in vacuum bags. Every few months I check the vacuum seal and pull a new vacuum and swap the desiccant bags if needed. I also have a bucket of silica gel beads that I fill my additional AMS dryboxes with (less than 10 USD/EUR per kg).
The only more expensive part is a filament dryer (< 100 USD/EUR if you go for a Sunlu or similar), if you don’t want to use your printer’s heatbet or an industrial drying oven (people use their ovens in their kitchen, which might be a health concern).
Do you guys leave PLA on your AMS Lite for long periods - or remove it for storage when not in use?
I only print now and then as a hobby etc, and filament could stay out for a week or two before it is used again. Should I be unloading from my AMS Lite and storing away between prints?
I’m in London. General humidity is around 60%…
im also in London. I keep my spools on the machine all the time and done see any adverse effects. I keep other spools in a box with some desiccant in when not in use, but Im beginning to doubt if it’s worth it to be honest. I think PLA is pretty forgiving - especially in our climate.
Of course - others may disagree - but this is what I do.
There is ways to improve the storage if you know what to look out for…
Bit long and slightly off topic
Real world dummy here…
A long time ago I could not resist a special for PLA and ordered way more than I needed.
Was only many weeks later and after finally unpacking all boxes that I learned some bags got damaged already.
Those were the first rolls I used and I had no real drama with them.
As the rolls were in sealed bags I did not bother too much with storage needs.
Only checked that the vacuum of the bag is still firm and they went into a cabinet.
Nothing is perfect any more these days, not even vacuum bags for rolls you had to pay a whopping 8 bucks for (due to the bulk volume)…
I kept getting rolls where the bag got floppy and to no one’s surprise these rolls required quite a bit of drying to be usable.
Not just that though…
I am still not 100% if it was from the fumes of the new cabinet, having stacked up 6 rolls each or the transport to my address that weakened the bags.
Anyway… The PLA was not as it should be, not even after drying it to anything from 20% down to basically nothing after a few days in the hot AU sun in a black container with dehumidifier salts.
It loved breaking in the telfon tubes, loved producing rough outer walls and within the same print creating super smooth walls with clear signs of under extrusion.
Now, almost 5 years later I still have a few rolls of this shipment I kept for customer prints where the colour mattered more than anything.
Not sure if they will print something successfully though.
What’s the lessons learned from this and having spend more hours fixing print issues than using this old filament?
For starters: Filament, even stored in sealed bags will age.
Filament will be affected by the environment over time, especially in areas like mine where temps and humidity levels keep going from one extreme to the next.
PLA and some other ‘biodegradable’ filaments are the worst here as they age the fastest.
Other plastics like Nylon for example can do much better and still print seemingly fine but might have degraded a lot for their physical properties, like flexibility and impact resistance.
I spoke an old friend of mine who is an expert in powder coating.
And he literally blew my mind when he explained the storage requirements for those plastic powders of the special kind they have to keep for many years.
Quality control and reference purposes he explained…
These sample loads of 10 to 20kg of powder are first broken up and loosened in like a ball mill contraption.
Part of the same machine is the filling station for the bags, anything from 100g to 2kg can be set.
A vacuum pump removes all air to replace it with dry Nitrogen before the process starts.
And the powder is 'purged" into the bags with a burst of Nitrogen to blow up the bag first.
Of course these bags are heat sealed after the machine removed the excess Nitrogen.
To finish off each bag is double bagged with thick polyethylene bags before going into storage - dark and kept at a chilling 15 degrees throughout the year with a constant 20% humidity.
He explained these insane measures as the result of decades his company does powder coating.
Twice a year all old samples are checked and if found failing they are re-bagged the same way.
Every time new sealing or bagging techniques are established all samples are re-done and checked.
It allowed them to keep their unique home blend colours accurate for several decades now he said…
Total overkill for our uses but worth thinking about…
What’s our real enemy here in terms of filament storage?
Is it really how humid our filament has become or is it other things it got exposed to or absorbed ?
Like it or not: It’s all of it…
Means we should have consistent environmental parameters for our filament storage, dry every roll before using it and prefer to use up our filament within 12 months or less.
Once something made it into our filament is it usually much harder to get it our again, not just water.
Ever noticed that some filament produce a certain smell when you get a whiff while opening the dryer to check or rotate the roll?
Correct! Even what’s supposed to be in our filament can escape while we dry it, so too much drying or too often can ruin it the same as bad storage conditions.
Ok, means we have to do better and worry more…
Nope…
Just don’t over stock and try to keep the currently unused filament is the best possible condition.
Prefer to only dry your filament once and to use it up.
If that’s not possible store those usually more expensive filaments with a desiccant that does not rely on temperature or minimum humidity levels to work.
Silica gel is not ideal here for long term storage if the filament has to stay very dry.
For long term storage it is really beneficial to also include a little oxygen absorption bag.
Quite cheap to order these days and they really help to make a difference for long term storage in sealed bags with dry filament.
Should you invest into one of these food vacuum sealer machines ?
Only if you use filament on a hobby level, anything above has a higher benefit from something larger that provides lower costs for the bags.
Easy to DIY as well:
Get a sealing strip combo from our usual online market places, make sure to get mains powered ones or a kit that comes with a matching power supply.
Make a box to fit the length of your strip that is large enough to fit more than just a roll of filament inside - you can use it for large amounts of food going in your freezer as well 
The key is to NOT use a vacuum but to instead put a lid on the box and the bag inside - with the opening going through the sealing strip.
A cheap upright hand pump for beach use is more than enough to pressurise the box and to drive all air out of the bag.
Unlike food sealers you can use any bag, no need for textured one allowing the machine to suck the air out
Sterilite 80 qt sealed tote with some additional clips. 15 bucks at Walmart (don’t know if you have them there?). Currently has 15 rolls in it, can easily hold 20 rolls.
I had similar for quite a while - not always easy to find good stuff in AU …
I also use buckets but their lids are a pain to get off - literally…
My storage worries never seem to end as whenever I thought I found the perfect solution it gives me ideas to try to improve upon.
Large volume makes things easy in terms of stacking up but also means a lot of air is exchanged whenever you need to get a roll in or out.
Not ideal for me at times with humidity levels going through the roof.
My final answer to the problem is now a work in project - a display fridge converted into a filament store.
The small scale bar fridge provided a proof of concept and showed internal volume is relative if the cold trap goes down to well under minus 30 degrees Celsius.
Getting the air flow right to ensure good circulation and that the filament to be dried won’t affect the stored filament too much is the tricky bit now.
And getting this big and top heavy fridge inside somehow to work on it as I don’t like doing it with the sun burning down on me outside…
PLA is pretty moisture tolerant. If you are getting zits or lots of stringing, then dry it. If not, don’t. It really is that simple.
With some other filaments (like nylons) which are very hydroscopic, drying is required - even printing from a dryer is sometimes needed.
So, it is dependent on the type of filament you use and how high the relative humidity is. Most common filaments you can simply wait until they aren’t printing properly and then dry them
That’s what matters - if your prints show moisture effects or not. But just be aware your prints can be fine until they aren’t and know what to look for.
The range of feedback just reflects people’s individual experiences. Extrapolating to “everyone” is flawed, though. It doesn’t work like that. Moisture effects depend on a number of things and ambient humidity is just one of them but a big one. Different shops can have different temperatures, humidities, air currents, etc, and one person’s “no problem” can easily be someone else’s disaster.
Even PLA can show moisture effects. I’ve seen it and it was cured by drying the filament. Much also depends on characteristics of the model you’re printing. You can provoke moisture effects just by printing a big model that is more susceptible to corner lifting for example. Stuff where surface uniformity is important can reveal moisture effects that might not matter or even be noticed on other models.
If you aren’t seeing moisture effects now, just keep the symptoms in mind for if/when you do.
Your humidity sounds like the humidity in my part of Canada in the not winter months.
I store my filament in bins that have a gasket with the lid. Not overly expensive at Walmart… perhaps Tesco for you would have something compatible.
Desiccant beads are a must….just print out boxes for them….there is a plethora of online models.
The filament dryer I have holds 2 rolls, and is less than $100🇨🇦 when it’s on sale pretty regularly; so probably £19.99 for you.
It’s better to be too safe than not safe enough. You don’t want filament issues when you’re working on an order for money, or gifts etc if you’re on a timeline.
Cheers fam
This is similar to what I do. In addition to the gasketed container, I seal each spool in a vacuum bags with rechargeable dessicant. I use a food dehydrator for recharging the dessicant and drying spools if they get too wet. While I am printing I put the dessicant jar from the spool bag in the dehydrator to recharge. It is a rare occasion That I need to dry a spool of PLA. PETG, ASA, and TPU require drying occasionally.
People worry too much about moisture. You can remove moisture and it usually doesn’t permanently damage filaments (I bet there’s probably some rare brands tho using unique formulations) but the reverse is worse. You can dry filaments and inherently cause the plasticizers to evaporate, leaving the filament brittle, and this is permanent as you can’t replace the plasticizers. I’m in the US midwest so I see tropical humid summers and terribly dry cold winters.
I found a cedar hope chest at a random antique place for 50$ or so once. Holds around 60 rolls, didn’t add any seals as it’s decently crafted woodwork with a good 1/4 flat vs flat all the way around where the lid comes down.