3D Printer Filament Dry Box - Keep Humidity Low

[Nifty]

see how much filament is left on the reel

Ouch, yeah, that would be terribly frustrating!

 

[The Hat]

@Nifty, a question for you ?...
How did you calibrate your Hygrometer to give the correct reading...?

 

[Nifty]

How did you calibrate your Hygrometer to give the correct reading...?

Um... I don't even know if that's something that can be done?

The dial one I have just goes from 0 - 100, and the digital one just shows the %. I don't know if either of them have any buttons or dials or anything for calibration.

I guess I could do as this video suggests and go through the "salt test" and look for a discrepancy... but I don't know that my filament will really care if my meter is a few % off.

 

[Nifty]

Ugh, @The Hat , now you got me all up-in-my-head!

See what you made me do!!!

 

[Nifty]

Readings at about 1 hour in are 81% and 89%.

I'm SHOCKED (not really) that these $1 China hygrometers from Aliexpress aren't 100% spot on!!!

For the purposes of what I'm doing, I don't really need perfect readings... but at least this is helping me see if they are working and to what degree.

Next step (after letting these sit for a few more hours) will be to do the same test with desiccant in the container!

 

[Nifty]

Ok, I opened it up yesterday mid-day, flushed out the air, let the humidity meters settle back to ambient 50%, then resealed. Within an hour, they were both pretty close to 75%.

Last night I opened them up again, flushed the air, and reset it. This morning:

 

[Nifty]

Ok, so after letting that setup (with salt) sit for a day at around 77-78%, I emptied the container, wiped it out, and put the hygrometers back in, but with 1/2 teaspoon of new desiccant.

It quickly started dropping... about 20% in just 10 minutes!

Then after about 2 hours, it had settled in at 15%, and stayed there for the next 20 hours.

No idea why it hasn't dropped lower. The beads have shifted to a little bit more clear/pink, but they still look to have life in them. Maybe the meters just don't go down that far?

I'll probably dump more desiccant in just to see if I can get it as low as possible, to eliminate any potential that it might be too little amount.

 

[The Hat]

I left my hygrometer in a salty plastic bag overnight and it seems to have worked and given a positive reading, so I’m a happy camper with my two AliExpress hygrometers, I’ll make up a new see through reel container when I get the one I’ve ordered, expected in this week.

@Nifty if your filament has as low a moisture content as your current meters are reading, then I reckon you will get perfect results with them now, below 50% is good...

 

[Nifty]

below 50% is good

This probably starts getting into a LOT of science that's over my head, but I wonder if there's a humidity level where PLA starts to absorb moisture? Example, is it anything over 0%... or is moisture in the air only a problem over something like 30% or maybe even higher?

I'll be curious what your meter says once you get it into your drybox!

 

[The Hat]

From what I can gather moisture only seems to be a problem when humidity stays above 70%, because I originally started out running ABS, with no issues till later in the year when the humidity levels started to climb up.

I then switched to PLA and the moisture problems that effected my ABS were gone but once again this issue raised it head when we had exceptionally high levels of humidity for the first half of this year, on average the humidity levels here usually stay around 65% and seem to cause no issues.

But I did notice some of my prints had sections where condensation must have affected part the filament roll , if I hadn’t use that reel for several weeks, the top half may have absorbed moisture and the bottom didn’t, who knows, I later cover the unused reel with a plastic bag. . (Stop gap)

but I wonder if there's a humidity level where PLA starts to absorb moisture? Example, is it anything over 0%... or is moisture in the air only a problem over something like 30% or maybe even higher?

We’ll never know the right answer to this because some will say moisture is not a problem and the next guy will say it is, and I reckon it all depends on the local climate you live in, we’ll just have to keep one eye on the hygrometer or keep everything in a seal box to be sure...

My current filament bucket with just Silica in it is working, but I’m looking forward to having one where I can see the hygrometer, Silica, and the filament reel visible and know for certain that moisture will no longer be a problem.

My next project will be to store all my unused filament in a controlled heated box and never suffer from the problems I’m having right now...