alt.hn

7/21/2026 at 3:52:05 AM

A Koi Pond Mosaic Made from 10 Pounds of 3D Printer Waste

https://www.instructables.com/A-Koi-Pond-Mosaic-Made-From-10-Pounds-of-3D-Printe/

by sudo_cowsay

7/21/2026 at 4:53:48 AM

So the author recycled 10 pounds of plastic, but used 8.5 pounds of glue to do so (184 sticks at 0.74 oz which seems to be average for glue sticks).

Cool project, but that ratio seems very ineffective. Especially since there is a realistic chance this ends up in landfill within some decades anyway.

by esquire_900

7/21/2026 at 8:56:06 AM

Like those "wood" tables that are 50% made of epoxy. It grinds my gears

by lopis

7/21/2026 at 9:25:01 AM

I'm so glad that fad is over. My mother worked as a theatre artisan before retirement and it was, among other things, fumes from curing epoxy that caused numerous health issues down the line.

by Tade0

7/21/2026 at 12:55:50 PM

I am curious about the down-the-line effects of fumes from printing PLA and PETG. Reddit posts suggest no ill effects, but it hasn’t been long enough in the hobbyist world.

by xattt

7/21/2026 at 4:19:36 PM

My printer is near a window so I just added an exhaust duct to the window, in the past when it wasn't close to a window I ran that duct through some filters (charcoal, furnace filter stuff) and left the end near an additional air purifier i had in the space.

by sleepybrett

7/21/2026 at 7:02:56 AM

Most of the environmental cost of plastic happens when it’s made. Once it exists, burying it in landfill isn’t nearly as bad as many people think.

95+% of the carbon footprint of plastics comes from production and manufacturing.

by fhub

7/21/2026 at 7:39:36 AM

Isn’t plastic nearly free as a raw material as a by product of fossil fuel production? I was always told it’s the opposite, plastic bags are better for the environment if disposed of properly because they’re so light weight to transport, didn’t need to be farmed, and companies basically give away the raw material because it would be more expensive to dispose of. A cotton bag needs to be reused upwards 1000x to be less impactful, or was I bamboozled?

by repeekad

7/21/2026 at 9:28:24 AM

We now know that, contrary to the cotton bag, they turn into microplastics which cost way more to remove from the environment than that reusable bag.

by Tade0

7/21/2026 at 10:00:57 AM

Not when they are properly used as a fossil fuel source. As a fossil fuel source that just happened to also make itself useful in other ways on the voyage from mine to smokestack. As long as we still burn coal for electricity and/or heat it's just stupid to bury plastics (or, worse, let it slowly decay unburied)

by usrusr

7/21/2026 at 10:33:47 AM

It wouldn’t be so bad if you buried it and it stayed buried it, but whatever disposal technology you use it doesn’t work if the plastic is never properly disposed of. Even if people are really careful, for instance, some single use plastics are going to blow away in the wind. Something shoddily made in the bottom of a pond is going to come apart and shed plastics, etc.

by PaulHoule

7/21/2026 at 8:09:39 AM

> Isn’t plastic nearly free as a raw material as a by product of fossil fuel production?

Yes and no. Oil is cracked down for lots of different things, but one of the things that people are really aiming for is ethane which can be used to make industrial ethanol, and a lot of plastics.

What you end up with to get there is lots of propane and butane, which is used as a fuel gas, but most of that ends up going up the flare stack because there's so much of it. We won't stop doing this while we still use plastics and fertiliser.

You need very clean propane or butane for things like cooking stoves, but you can run car engines on it just fine because they're so much less picky, and the exhaust gases are far cleaner than engines run on heavier fractions like oh maybe octane. This is why things like warehouse forklifts run on gas instead of diesel or petrol - you don't die if you breathe in the fumes, because there's no unburnt fuel or carbon monoxide, because it runs as lean as a vegan's dog.

by ErroneousBosh

7/21/2026 at 12:14:32 PM

>What you end up with to get there is lots of propane and butane, which is used as a fuel gas, but most of that ends up going up the flare stack because there's so much of it. We won't stop doing this while we still use plastics and fertiliser.

The amount of gas flared globally adds up to little over 1% of global energy production. I know that doesn't sound like much but we're talking like terawatts. It truly is a mind boggling amount of energy that gets wasted because we simply can't get it to users cheap enough.

by cucumber3732842

7/21/2026 at 5:15:00 PM

If only all (or almost all) of it was flared! Methane is a much more potent greenhouse gas than CO2, and unfortunately there is still a lot of it escaping from oil installations unflared (https://www.iea.org/data-and-statistics/charts/potential-emi...).

by rob74

7/21/2026 at 10:14:15 PM

It's a pain in the arse to run vehicles on methane (CNG) because it has to be stored at around 250 bar (or, 3600psi in Old People Units), and it's really not very energy-dense so you need a lot of it.

Again though flaring it off in a gas turbine to generate electricity and heat would be ultimately less harmful than just letting it out into the air.

By contrast the tank in an LPG vehicle is at around 8 bar, not a hell of a lot more than the pressure in a truck's tyres. On my old Range Rover the LPG tank is considerably less spicy than the air suspension tank at 15 bar, which is getting into "this can injure you" territory.

by ErroneousBosh

7/21/2026 at 1:06:15 PM

> because we simply can't get it to users cheap enough.

Or we can't get it clean enough to use as say cooking gas or aerosol propellant.

Stick it in cars, they'll burn any old shite and emit water and carbon dioxide - two terrible greenhouse gases, for sure, but you'll extract useful work from it instead of literally just heating the atmosphere for the fun of it.

by ErroneousBosh

7/21/2026 at 10:00:46 AM

It also burns quite well. If are in a location that burns trash in waste-to-energy plants you can get a decent amount of that energy back by throwing it away

by wongarsu

7/21/2026 at 11:46:50 AM

"burying it in landfill isn’t nearly as bad as many people think."

I think you're full of shit.

by SirFatty

7/21/2026 at 5:43:18 PM

What does that have to do with anything? The point is to do something cool with it.

It far more effective than building a collage with bought or new printed parts

by s1artibartfast

7/21/2026 at 4:56:54 AM

Honestly wtf does the glue matter when people are going through plastic like it's nothing? Bringing up the glue is such a weird nitpick.

by chneu

7/21/2026 at 5:32:12 AM

When the ratio is almost 1:1 it is a bit more than a nit.

by ofrzeta

7/21/2026 at 5:33:09 AM

Do nothing: 10 pounds of filament poop has go to the landfill.

Do this thing: 10 pounds of filament poop still exists, + 8 pounds of glue sticks (which is basically a thermoplastic) used, to create something that's eventually going to end up in a landfill.

Are you being deliberately obtuse?

Recycling or reuse is not as useful as just not creating waste in the first place.

by isoprophlex

7/21/2026 at 6:37:26 AM

Maybe it looks more amazing in person than in pictures. If not, and the point is a message about waste, then the 80% increase could be cast as part of the message.

Let’s say every month the artist repurposes the last pile of plastic with more glue. At the end of one year, the 10lbs would turn into 1100lbs. At the end of two years the original 10lbs would have turned into 1.3 million lbs of plastic waste. Surely that would frame a very powerful message about plastic waste and green washing misleading public policy.

by rz2k

7/21/2026 at 6:31:07 PM

Or do something entirely different and 100lbs go to the landfill.

Reuse is good if the activity replaces something that would generate more waste. This is the real benchmark, not the case where someone does nothing.

The most efficient thing is always to do nothing and/or kill oneself. This isnt practical, so reusing used materials instead of new when you do something is still net good.

by s1artibartfast

7/21/2026 at 5:35:46 AM

So... don't 3D print anything?

by sudo_cowsay

7/21/2026 at 6:58:40 AM

Reduce, reuse, recycle.

by tonyedgecombe

7/21/2026 at 5:33:21 AM

hot glue is a petrochemical just like plastic.

by staplor

7/21/2026 at 2:32:47 PM

They do make biodegradable hot glue [1] but it's still not perfect. It's biodegradable and certified compostable under industrial conditions but it still has a polymer base. It's also not ideal for projects that are always in UV light.

https://www.poweradhesives.com/adhesives/tecbond-214b/

by smith7018

7/21/2026 at 5:34:48 AM

It is plastic, nothing else.

by ofrzeta

7/21/2026 at 4:23:41 PM

Why use glue at all, he should have done this using a 'stained glass' method. Build some kind of a frame for each area of color and then melt the filimant into it.

by sleepybrett

7/21/2026 at 5:29:37 PM

I save all waste from 3d printing with good intentions.

I did back the Creality shredder and filament maker that hasn't shipped yet, but I'm optimistic. (https://crowdfunding.creality.com/)

I also bought a pellet extruder kit, which can use shredded PLA waste, but haven't gotten around to putting it on a printer. (https://greenboy3d.de/)

I've had pretty good luck taking waste and melting it into silicone molds. Doable with a cheap toaster oven and purge waste and other scraps (though you need to break down larger waste)

For those who want to recycle filament without doing the work themselves, this person has such a project (and maybe there are others out there): https://erikaprintsshop.wordpress.com/

by bdcravens

7/21/2026 at 4:39:07 PM

A couple of years ago I listened to a Lex Fridman podcast with a researcher at the MIT Media Lab. I don't know the status of it, but the researcher spoke about how people in developing countries were experimenting with using local resources as 3D printer feedstock - things like ground-up sea shells - as a way of using local supply lines.

One of the most interesting things he said was that the current waste from 3D printing (and other technology) is really a sign of technical immaturity; nature repurposes everything - there is no trash in an ecosystem, only food for something else. Maybe we'll eventually learn to build infrastructure like that.

by joshmarlow

7/21/2026 at 5:38:30 PM

For most people, waste -> filament recycling is a red herring (cost and time). Happy to see people thinking more laterally. I use an old toaster oven ($5 used) to fabricate round stock (fill old aluminum drink cans with waste, melt it down) and sheet stock (crush the melt between flat surfaces). I then use this material for all sorts of things (it makes beautiful marbled vases on the lathe, for example). There's almost zero net waste in this process (I recycle the cans).

More uses I have in mind:

- PLA drift sleeves for go karts (they're typically ABS, which, if you care about plastic in the environment, is a laughably bad choice for something which is intended to be ground to a fine powder in use)

- Stool (melt plastic into shallow cylindrical mold, push legs into melt)

- Decorative trim/picture frames (need a profiled router bit)

etc etc

Check Brothers Make on YT, they are the source of my inspiration.

by gia_ferrari

7/21/2026 at 9:15:28 AM

I guess this is meaningful recycling also because it occupied the author.

Otherwise the author would have started a different project and likely would have consumed more material.

Sibling comments focus on the end result and that it might end up in trash - but that was always the plan.

by thih9

7/21/2026 at 1:56:26 PM

Using the prints themselves as glue rather than buying glue for them would make this a more interesting form of recycling.

I wonder if you could make a large hand-driven low-resolution 3d printer which, rather than running on filament, had a hopper that you fill with failed prints. Really just a giant hot glue gun.

by __MatrixMan__

7/21/2026 at 7:28:45 AM

It's really annoying to me that shredders and filament makers are so expensive. I probably generate less waste than average from my printer, but it still pains me to have to just throw it away because I can't do anything productive with it

by voidUpdate

7/21/2026 at 12:22:10 PM

A filament extruder is essentially an injection molding extruder head without the press and mold - it's pretty advanced technology that requires integrating thermal design, mechanical components, and precise electronic monitoring and control. To get anything close to consistent output you're probably going to need a lot of special cutting and extrusion screws and probably some kind of additional pressurization system, and then the user still has to be disciplined about sorting and cleaning their plastics to get a probably mediocre output. Something like: https://www.instructables.com/Recycled-PLA-Sheets-From-3D-Pr... might be a more practical recycling paradigm for 3D printer waste.

by t-3

7/21/2026 at 12:18:05 PM

If you heated with wood you could just burn it (and a whole lot of other things). Obviously not ideal above a certain population density...

by cucumber3732842

7/21/2026 at 4:52:55 AM

The only comforting thing to me about the waste (apart from the fact that our personal 3d printer waste is a margin of error compared to industrial waste so honestly, just don’t worry about it), is that at least PLA is biodegradable.

by atonse

7/21/2026 at 5:37:26 AM

"the term biodegradable used by manufacturers and distributors can be somewhat misleading for the final consumer" https://www.beease.com.hk/post/how-long-does-pla-take-to-dec...

by ofrzeta

7/21/2026 at 6:25:05 AM

This is also misleading. PLA plastic degrades slowly in the environment because it's highly crystalline and mechanically robust.

But once it's fragmented, it's rapidly degraded. So it doesn't contribute to persistent microplastics.

It also does not take 80 years in normal environmnets.

by cyberax

7/21/2026 at 7:20:58 AM

Well, my source (quoting some "Federal Environment Agency") says it does contribute to microplastics. Some googling seems to confirm this.

by ofrzeta

7/21/2026 at 3:06:51 PM

It is likely a fraction of a fraction of an already small fraction. Textiles, tires and food packaging are the biggest contributors. It has yet to be proven that microplastics are directly linked to any harm, it is mostly unknown.

If you care about that kind of stuff the best thing you could do is stop driving.

by vablings

7/21/2026 at 5:47:50 AM

Interesting. I will do more research on this, thanks. But at the end of the day, even though it's tough for us to see the PLA poop, etc from our prints (I still generally don't like it), my point is that hobbyist plastic waste is basically negligible and making nearly zero difference.

I don't want people to see plastic waste from 3D printing and be discouraged to try it out as a hobby. I just got my first 3d printer 6 months ago (and I did all this biodegradable research mostly so my wife would feel comfortable with it). But the benefits of rewiring your brain in a manufacturing mindset, having the ability to create things, solve custom problems, etc, far outweigh the negligible (in the grand scheme of things) amount of waste compared to all the other plastic shit (toys, etc) the masses buy on amazon. That was my main point.

But it's good to know that it could still take 80 years, and is not as quickly biodegradable as originally thought.

by atonse

7/21/2026 at 7:10:10 AM

Have you tried PHA? Supposedly it's truly biodegradable and a viable alternative to PLA in many cases.

by drupe

7/21/2026 at 5:18:33 PM

Is this just delayed trash? At some point someone will throw it out.

It would be great to be able to create "art" and add something that degrades it.

by is_true

7/21/2026 at 5:28:33 PM

In the end everything is delayed trash. Some trash is recyclable/compostable/etc.

by syntheticnature

7/21/2026 at 7:36:45 AM

Why is the primary image blurry on mobile but high res if I rotate my phone horizontal?...

by repeekad

7/21/2026 at 10:05:10 AM

I took a quick look because that sounds odd. They've made a mess of the article's image sizing - only 270px wide if the viewport is <768px. (That top image is 1024px wide on desktop.) There's so much wrong with that decision, regardless of the huge difference between 270 and 768, e.g. apparently not being aware of hardware pixel density on smartphones.

by abanana

7/21/2026 at 4:37:30 PM

>generating an ima--

barf

vomit even.

by lardosaurusrex

7/21/2026 at 4:24:39 AM

bravo! so much better than a landfill

by bogometer

7/21/2026 at 5:37:37 AM

next week my kids arts and crafts project is top news.

by o0void0o

7/21/2026 at 9:26:29 AM

Share it now; I'm sure many people (with me included) would find it interesting, just like this post.

by thih9

7/21/2026 at 1:49:36 PM

Does no one else notice the LLM-speak tone of this article? Does no one else mind?

by segh