PLA exposure to water

[Tinker12]

Hi,
I'm printing some small parts to be submerged in tap water for long periods, months to years. I want to know if I use
PLA to make these parts, will they degrade or change over time. I have read that PLA absorbs moisture from the air.
Does anyone have experience with this or recommendations. I plan to buy some T-Glase filament and try also.

Thanks

[bubbasnow]

are you wanting these items to be water tight?

[Tinker12]

no, they don't need to be watertight.

[Polygonhell]

Technically PLA is biodegradable, but my understanding is it requires both heat and moisture for there to be any real effect.
My guess is it would probably be fine, but I don't know of anyone who has tested it.
ABS would be fine, as would nylon or TGlass, so I'm not sure it's worth the risk.

[Tinker12]

Thanks for the feedback,
just for fun, and trying to post photos, are the parts, these are a bit off as the infill is not joining the perimeter, the latest ones are better.
https://www.flickr.com/photos/123952550@N03/
[img]https://www.flickr.com/photos/123952550@N03/[/img]

[mhackney]

I've had 2 of my tenkara line holders submerged in room temp water and there is no noticeable change.

[McSlappy]

PLA is a bioplastic, but as far as general use is concerned just think of it as a regular plastic with a low glass transition temperature (go-soft-temp in technical terms). Companies use it every day for holding liquids with no issues as it's not water soluble (plastic cups and plastic meat trays are common). I wouldn't be afraid to use it submerged.
I say that, but it depends on what sort of water you're putting it into - my dad got some PTC fittings for his pool and the plastic fell to pieces within a month, but that's from the chlorine not water.

@Mhackney, how does PLA hold up in salt water - are the line holders in salt or fresh?

[precisionpete]

I printed some covers for sink pop ups that get hot & cold water on them. In use for ~ 3 weeks now without any noticeable degradation.
Printed in white pla & t-glas.

[mhackney]

I'm only testing in fresh water but that's a good question about salt water. Time to setup another test!

cheers,
Michael

[McSlappy]

Sorry, I've just made more work for you :/

[mhackney]

No worries, at least it's quick to set up!

[bubbasnow]

I'm only testing in fresh water but that's a good question about salt water. Time to setup another test!

cheers,
Michael

be sure to get your salinity right!... if you live next to the salt lake like i do, it can be anywhere to 4-8 times the salinity of the ocean.....home to two types of species.. brine shrimp and brine fly.. blah... blah .... blah... Ive listened to the AM info channel tooo many times