I think there is a misunderstanding of humidity in general. I live in tropical North Queensland. I was surprised to read in the OP that Hamburg sits at an average of 78% humidity, when here it rarely gets that high and when it does it is unbearable. With that said what is 78% humidity at 16C compared to 78% at 35-40C
If the issue is absorbsion the ambient temp of the material must play a part. Mr Arizona supports this theory. From my experience of Arizona (limited to the Sonora desert) is lip cracking dry out of wet season but hot and humid (like North QLD ) in the wet.
Just food for thought. I dry btw.
A very interesting and thought provoking post. I love it when someone actually does systematic tests and measurements. The mention made (somewhere on the page 
) about RH versus absolute humidity, is especially intriguing.
So many people have almost diametrically opposite experiences. I myself got traumatised by having to toss out a few partial rolls of filament that were very old and failed to respond to a food dehydrator, even for 48 hours. So these days I do the full silica paranoia thing (sillyphobia?), even with my PLA.
I think the whole thing just has too many variables. PETG ain’t PETG; every brand has its own special sauce. Ambient conditions vary. Observational and deductive skills vary - hugely. Dunning Kruger often rears it’s ugly head.
We need someone with the time, interest, and resources to do proper research, probably in a university setting.
First lets address your logical fallacies.
You are appealing to authority stating that with x amount of experience your claims about wetg are true
You claim that because you dont have a problem printing wetg, no one else should.
Finally you offer that you “ don’t get it - do any of you have real before/after pictures of prints that got better after drying - without changing anything else?” So if no one produces evidence you can only conclude you are right.
So you are attempting to make an argument based on nonesense. I can, with evidence, prove you wrong. But I wont because your argument is embarrassing and to borrow your stance, “it would be a waste of energy.”
Hows that for being deliberately provocative?
Yes I understand how plastic works. Im saying I have never had this issue, I have never dried filament, and I dont live in the wettest climate but not the driest by any means.
The machines change over time so maybe they are more tolerant nowadays than they were before.
Try printing clear PETG. When it is dry, it will extrude a nice clear thread. When it is wet, you can see the thread full of bubbles. The part might still print, but it shouldn’t have the same mechanical properties.
I live near Washington DC ( 60% Avg RH per your interpretation) and I need to dry it.
Well, I’ve often wondered about that myself, now I live in the desert southwest of the United States and my humidity levels are, lets just say not a concern. But I have been printing since 2016 and I leave all of my filaments out in the open. After about 4 years the PLA will get brittle and the nylons will finally start to show minor signs of moisture but nothing else is affected. Since I have no humidity to speak of Ive always wondered how the rest of the world gets bye.
Thank you for publishing this very interesting and provocative article about filament drying.
I bought my first 3D printer about three years ago (Artillery Genius) and recently my eighth (BL P1S). I’lI spare you an exhaustive list, but as I suspect the same is true of most of you I am a tinkerer, so I know how to take them all apart and put them back together, and I have quite a lot of experience with the most of the other factors in actually printing something; such as bed-leveling, bed and nozzle temps, speed, etc…
Now to the filament humidity part of this discussion: Of the hours and hours of 3D printing YouTube videos I watch I usually see a wall of open spools of filament – no boxes and no plastic – and this is seldom discussed. I religiously store my 60+ boxes of filament in their original boxes and plastic bags, together with desiccant packs and spool inserts (I buy silica gel by the kilo). It’s a major pain to do this, but everyone always talks about how important it is to keep your filaments dry. With silica gel inserts my AMS never goes above 10% RH.
Then I finally asked Google Assistant at what humidity 3D filaments should be stored: “To get the best print quality, keep the humidity level where you store your filament and where you print below 45 % relative humidity (RH). At levels above 55-60 %, you will see problems.”
Any comments on all this? Am I wasting my time opening and resealing boxes of filament, or should I just build wall racks like everyone else?
Average yearly humidity in our community is 77.70% (blue line). I can’t ignore humidity or wet filament because moisture DOES affect all my prints, even using PLA.
State (Ohio, red), U.S. (green)
Leave a few spools out, see what happens when you print with them.
Some of us know from experience that moisture has a negative effect on our prints, so we expend a great deal of time and effort to get and keep our filament dry.
Some know from their experience that they don’t need to care about moisture.
Do what works for you.
I have been printing with PLA, PETG and TPU for about 6 years. In my room where my printer and filament are, I usually have around 60%-70% humidity.
I store my filament in Ikea boxes (without seal)
I use FILAMENTS from “extrudr” ONLY.
So far I have been able to get by without any filament drying and have always been happy with my prints.
Just 2 weeks ago I discovered that my TPU was very difficult to print. It kept popping out of the nozzle…
Throwing away all of my TPU wheels and buying new ones would cost me over €100.
So I ordered the Sunlu S2 (2023 version) a week ago and dried the rolls with it. Now the print quality is VERY GOOD! I’m excited!
However, I have to say that it is not necessary to dry PETG or PLA if you store it properly…
TPU absorbs moisture much faster, so I will probably only use the Sunlu 2 for TPU…
The Sunlu requires 0.235 kWh for 6 hours of TPU drying
Given my electricity price, this costs me €0.06 / 6 hours
Accordingly, each hour of operation of the dryer costs €0.01
I think that’s ok and proportionate.
Producing, buying and shipping new filament definitely costs more money and CO2.
Just a quick point - OP didn’t say that dehydrators didn’t work to remove moisture from the filament, he said that for his PETG inventory he hasn’t seen any difference in print quality before or after drying.
Wasn’t the title intended to be both a joke because it’s “Click Bait” style? If not I am getting old and my sense of humor might be defective.
That was not what you were saying at all though, was it? Maybe you need to go back and reread your comment.
You were clearly saying the wet filament isn’t really an issue and that anyone suggesting otherwise is dumb and that suggesting drying filament is dumb because you can’t believe that it can cause issues like weird patterning on prints. You also said that dehydrators are overpriced and don’t do anything.
That is not just saying you have never had to dry filament, now is it? That is spouting a load of nonsense that just isn’t true. Moisture in filament can affect it in lots of different ways and it is very easy to prove that dehydrators do work, both with getting less moisture related issues and the fact that the weight of the spool decreases when dried.
Don’t go trying to backpedal now saying that you were just saying you’ve never had to dry filament, that was not all of what you were saying.
That depends on the filament. PLA will be fine in the open for the most part in most areas and most of the walls of filament you see on YouTube are PLA. More hygroscopic materials absolutely need stored properly though, things like nylon and especially water soluble filament like PVA.
It will all come down to personal experience though. I have been fine printing TPU and PETG that sits out in the open for months and I have had issues with PLA not long after I got it. For nylons and other similar materials I always keep them stored properly, partly to do with cost, if the material is expensive, even if it shouldn’t be hygroscopic, I store it properly anyway just because I don’t want to waste it.
What I do is for PLA and other cheap filament I just leave it in the open and if I have moisture related issues later on I dry it then. However moisture will breakdown filament over time so it is best to keep it in a low moisture environment or store it properly to extend it’s shelf life.
Bambu forums aren’t good at showing who you replied to, I wasn’t replying to OP, I was replying to someone else in the comments who did say:
Oh that’s funny! I was very confused on that one, makes sense now that I see the other comment too!
Danke für diesen Beitrag
Keep up the great videos
There is nothing wrong with being ignorant. That’s what these forums are for, isn’t it? To share experiences and improve the community? I do have a problem with people that claim an entire thread is pointless even though there is significant good discussion. If you don’t find value in what is discussed, just move along. Don’t be a troll and let the grownups speak amongst themselves.
Sadly the english language has deteriorated to a point where the word ‘ignorant’ has taken on a derogatory and offensive meaning when that was never intended. These days probably ‘uninformed’ would be a better choice of words.
Not at all, words alone do not solely convey meaning, tone and context do too. You can use the word “ignorant” in a non derogatory or offensive way, although it is more often used to be offensive.
All languages evolve and change over time, that is not the language deteriorating.
That very much depends on what you actually want to say, in the uses of “ignorant” above, “ignorant” was a perfectly fine word to use, using “uninformed” would not have had the same meaning.
“Uninformed” and “ignorant” whilst having similar meaning do not have the same meaning.