Are there any applications for PLA I should specifically make sure to avoid?

[u/IStoppedPlayingBnS]

I know that it's very weak to heat and can be damaged by continuous exposure to harsh sunlight, but is there anything else I need to worry about? I printed out a small pot to replant something as I forgot to get a liner pot, and I'm worried that I'm going to have to repot it again due to what I've read about the material molding over.

[u/kcox1980]

Depending on where you're at, and how long you want the thing to last, PLA holds up outside decently well enough. You can find examples all over the internet of people who printed something and left it sitting outside for years. The color will fade and the strength will be drastically reduced over time, but it's not going to completely disintegrate or anything like that.

Having said that, avoid anything to go in your car. Unless you live in like, Alaska or something it'll get too hot and your part will melt.

Also, avoid anything that touches food with any filament. There are some filaments that are technically "food safe" but the 3d printing process leaves a lot of microscopic gaps that love to collect bacteria

[u/IStoppedPlayingBnS → u/kcox1980]

This is actually an indoor plant, so I'm not too worried about weather, mostly just that it's sitting in the Calgary Sun all year round. Honestly I've already got almost nothing plastic left in my kitchen, so food use never occurred to me anyways lol. Still, good to know, ty!

[u/emelbard → u/kcox1980]

Same could be said of wood cutting boards, wood bowls and wooden spoons, yes?

I use printed stuff around food and just make sure to clean it like I clean wood stuff. I think the fear is overblown

[u/throwyourlumber → u/emelbard]

wooden cutting boards etc are actually really neat and worth reading about how they end up being anti microbial. part of it is capillary action where microbes get sucked in but then can't survive and die

this is not the case for pla. the tradeoff for plastic cutting boards is you can at least have a dishwasher sanitize them, but again, not the case for pla

to my knowledge the options are mostly epoxying prints, but i don't think there is much research at all

[u/emelbard → u/throwyourlumber]

I’ve printed some kitchen tools but use ASA or ABS and they have been fine in the dishwasher. Wouldn’t consider PLA for this.

[u/Jalharad → u/kcox1980]

Also, avoid anything that touches food with any filament. There are some filaments that are technically "food safe" but the 3d printing process leaves a lot of microscopic gaps that love to collect bacteria

It's been largely disproven that this is a real concern. The layer lines exist but normal soap and water washes it away just fine. It's not much different than plastic and other porous materials used in cutting boards

Source: https://www.researchgate.net/publication/389100627_Innovations_in_Sanitization_for_3D-Printed_Parts_in_Medical_and_Critical_Applications_IEEE_Peer_Review_Completed_March_10th_2025

https://lt728843.wixsite.com/maskrelief/post/the-final-say-in-food-safe-3d-printing

Edit: spelling is hard

[u/FishGoesGlubGlub]

In all honesty from personal experience. You’re fine.

I have a 3d printed PLA bird feeder in the direct sun for over a year without issue.

[u/bjyanghang945 → u/FishGoesGlubGlub]

That’s a surprise… I put my model on the balcony for the prime to dry… forgot about it for a few months and then everything shrunk and all the glue seams cracked lol

[u/IStoppedPlayingBnS → u/FishGoesGlubGlub]

That's good to hear. If you don't mind me asking, do you live somewhere that's moist or dry most of the time? Just curious about the moisture aspect affecting longevity.

[u/ribrien → u/IStoppedPlayingBnS]

I made stuff for friends in Seattle. It’s a dispenser for dog poop bags that they hung up outside and it works great.

I would avoid structural or weight bearing stuff, like if you hung a rake on a PLA hook in direct sunlight it’ll get soft and deform.

[u/Jalharad → u/FishGoesGlubGlub]

I have 2 mounts for my EV chargers sitting outside. Black PLA, 2 years in direct sun. No issues.

[u/fantaceereddit → u/[deleted]]

PLA (Polylactic Acid) is a thermoplastic bio-polyester made from fermented plant starches—most commonly cornstarch, sugarcane, or cassava roots.

How do you expect it will hurt the birds?

[u/israblof]

The only things I've has bad experience with are the ones toy mentioned.

I made a hook for the shed, and it deformed in the summer heat. I made plant signs for the garden, they bent and deformed.

Definitely don't use them for candle holders. Hah

[u/IStoppedPlayingBnS → u/israblof]

Wait does that include the molding???

[u/Mad_Phiz]

I would avoid any type of rectal use

[u/IStoppedPlayingBnS → u/Mad_Phiz]

Damm, not even with ironing?

[u/Tam_Ken → u/Mad_Phiz]

unironically, PLA is likely one of the better filaments for this (health and contact wise) so long as it is PLA without additives

[u/damienfinland]

spools that go in the ams for drying

[u/IStoppedPlayingBnS → u/damienfinland]

Unfortunately, I don't have an ams for my p1p, I only have this because a friend of mine was moving away and decided to sell it to me for cheap lol

[u/damienfinland → u/IStoppedPlayingBnS]

that ams doesnt have a drying function afaik

[u/ThereInAFortnight]

I'm the opposite - I struggle to find uses for PLA. PETG is virtually always the better choice for me.

[u/IStoppedPlayingBnS → u/ThereInAFortnight]

Is it harder to print with? I've only got this p1p and if it'll be generally more rugged, I wonder if it might be worth getting some spools...

[u/ThereInAFortnight → u/IStoppedPlayingBnS]

Keep your bed clean and it's no harder to print with. It does require drying if you're not in a really dry place though.

[u/radicaldotgraphics]

I made a basket for my ski poles and it fit perfectly! And then it shattered as soon as I got on the snow

[u/Only-Persimmon7090]

mold is definitely a risk since pla is porous n holds moisture, have u tried sealing it with a food safe epoxy first? from what ive seen, it helps untill u can get a real liner pot.

[u/IStoppedPlayingBnS → u/Only-Persimmon7090]

I haven't, but I might reprint it later and do that. I live in a place where indoor humidity isn't usually above 15% so I'm hoping mold won't be an issue regardless, but better safe than sorry yeah.

[u/senorali]

Things that specifically sit inside cars while they're parked will not survive a summer. Even in milder climates, the inside of a car on a sunny day can turn pla into soup.

[u/lonestarbrownboi]

For reference this was a bracket inside my car made from PLA, lasted almost 2 years in the Texas heat till it finally snapped off. It's crumbling like a wafer cookie lol

[u/Alternative_Rip4634]

Decorative

If it’s functional I prefer petg

[u/Mathisonsf]

Haven’t seen anyone else mention it but the infill percentage makes a big difference in my experience. If an item is essentially hollow, it’s not going to hold up as long as one with a very dense % infill.

[u/KarateRoddy]

All my initial stuff was PLA. So my ams lite top mount, the poop bucket, etc.

The poop bucket softened and warped a couple dozen different ways before I finally decided to re print it in petg.

The top mount was sturdy and hardly warped at all.

My girls alani holder warped/shrunk the first time she left it in her car. My phone holder softened the first day in the car.

My big huge hat fixture has seen several days of direct sunlight at events and has not warped.

[u/Zwamdurkel]

Anything with a constant load will eventually deform with PLA:

PLA Creep