<p>You don't provide information about the part, but in general PETG, ABS, ABS plus/Pro and ASA are not going to have any issue with humidity for a long time. If it's outdoor, avoid ABS and use PETG or ASA.</p>
<p>What is important is to keep the filament dry BEFORE printing. After printing, no problem. In fact, nylon after printing can be wet on purpose to significantly increase impact strength (and reduce tensile strength).</p>
<p>PLA in high humidity environment may lose some of its strength, but there are PLA parts under the rain which hold perfectly for long time, if they are not loaded significantly.</p>

CC BY-SA 4.0
2021-04-20T13:09:59.357Z
PLA works perfectly fine in submerged saltwater application (which is often considered corrosive) if printed well enough (5 walls, 10 tops&bottoms, printed sealed), but indeed, it does creep under stress and deform permanently. The test part I have experience with is a simple swimmer in a tidal measure device, carrying a little lead weight inside and a metal foil reflector on the top.
Trish
CC BY-SA 4.0
2021-04-20T13:24:55.593Z
PLA becomes brittle under moisture.  So, you want it thick enough to stay rigid.  PLA doesn't seem to work well on flex designs anyway.  PLA's strength is dimentional accuracy, but I don't know if moisture causes it's dimensions to change.
Perry Webb
CC BY-SA 4.0
2021-04-20T13:34:22.093Z
Note: PET is used for bottled water bottles.  Glycerin is added (PETG) to make it 3D printer friendly.
Perry Webb
CC BY-SA 4.0
2021-04-20T16:09:19.327Z
@Trish my answer was based on https://web.archive.org/web/20160330042542/http://www.protoparadigm.com/news-updates/weathering-of-3d-printed-pla-objects
FarO
CC BY-SA 4.0
2021-04-20T20:47:58.930Z
@FarO Sure PLA ages and will crack some day, but with some 2 millimeters wall thickness that *bulb* was able to stay a floating item after spending almost a year in harbor water. It was a simple flotation device, but it spent about half its life underwater: it got submerged when the water in a particular flat spot was giving enough depth for ships over a given draft but swam at surface level when not.
Trish
CC BY-SA 4.0
2021-04-21T06:30:10.283Z
@Trish I believe you, I just provided the source for my statement. It could even be that between 2013 and today the blends have changed. PLA in 2013 was quite a new thing.
FarO
CC BY-SA 4.0
2021-04-20T09:25:31.177Z
2021-04-20T09:25:31.177Z
FarO
<p>I'm working on a project to design some custom 3D printed parts for an indoor urban farm where the environment has a very high humidity of above 80%. What would be the best filament to use that will be able to handle this conditions. Are there any coatings that I can use to protect the parts from absorbing moisture?</p>

CC BY-SA 4.0
2021-04-20T09:20:27.133Z
Which kind of part is it? is it under significant stress? how long should it last? Most filaments absorb moisture, but then they are fine. Moisture is an issue BEFORE printing, if the filament is humid.
FarO
CC BY-SA 4.0
2021-04-20T13:07:27.610Z
Too many factors not listed, making this opinion based or requiring focus
Trish
CC BY-SA 4.0
2022-03-21T10:42:47.830Z
How is this question closed? The answer is simple: ASA.
AzulShiva
<filament><filament-choice>
Best filament to use in high humidity environment?
Khayhen Sarveswarah
# Best filament to use in high humidity environment?

(Asked by: username_0 on 2021-04-20)

I'm working on a project to design some custom 3D printed parts for an indoor urban farm where the environment has a very high humidity of above 80%. What would be the best filament to use that will be able to handle this conditions. Are there any coatings that I can use to protect the parts from absorbing moisture?

**Tags:** filament, filament-choice

> **Comments:**
> **username_1**: Which kind of part is it? is it under significant stress? how long should it last? Most filaments absorb moisture, but then they are fine. Moisture is an issue BEFORE printing, if the filament is humid.  
> **username_2**: Too many factors not listed, making this opinion based or requiring focus  
> **username_3**: How is this question closed? The answer is simple: ASA.  

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## 1 answers

### Answer by username_1 on 2021-04-20. Score: 7

You don't provide information about the part, but in general PETG, ABS, ABS plus/Pro and ASA are not going to have any issue with humidity for a long time. If it's outdoor, avoid ABS and use PETG or ASA.

What is important is to keep the filament dry BEFORE printing. After printing, no problem. In fact, nylon after printing can be wet on purpose to significantly increase impact strength (and reduce tensile strength).

PLA in high humidity environment may lose some of its strength, but there are PLA parts under the rain which hold perfectly for long time, if they are not loaded significantly.

> **Comments:**
> **username_2**: PLA works perfectly fine in submerged saltwater application (which is often considered corrosive) if printed well enough (5 walls, 10 tops&bottoms, printed sealed), but indeed, it does creep under stress and deform permanently. The test part I have experience with is a simple swimmer in a tidal measure device, carrying a little lead weight inside and a metal foil reflector on the top.  
> **username_4**: PLA becomes brittle under moisture.  So, you want it thick enough to stay rigid.  PLA doesn't seem to work well on flex designs anyway.  PLA's strength is dimentional accuracy, but I don't know if moisture causes it's dimensions to change.  
> **username_4**: Note: PET is used for bottled water bottles.  Glycerin is added (PETG) to make it 3D printer friendly.  
> **username_1**: @username_2 my answer was based on https://web.archive.org/web/20160330042542/http://www.protoparadigm.com/news-updates/weathering-of-3d-printed-pla-objects  
> **username_2**: @username_1 Sure PLA ages and will crack some day, but with some 2 millimeters wall thickness that *bulb* was able to stay a floating item after spending almost a year in harbor water. It was a simple flotation device, but it spent about half its life underwater: it got submerged when the water in a particular flat spot was giving enough depth for ships over a given draft but swam at surface level when not.  
> **username_1**: @username_2 I believe you, I just provided the source for my statement. It could even be that between 2013 and today the blends have changed. PLA in 2013 was quite a new thing.  

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