Used 99% Alcohol

[Affinity]

Best CYA advice is to do research and follow State and local guidance for proper Hazmat disposal.

This is how its done.

 

[Gru]

This is how its done.

Were all doomed. Hooray technology! Do you think a recycling facility doesnt just take your money and drive it to the landfill?

THAT is exactly what they're doing with the East Palestine "clean-up". Curious how they had to ship it to Pennsylvania, Michigan and Indiana. But hey, the EPA says the air is ok (in spite of independent laboratory testing coming up toxic),so what's the big deal?

(BTW, I live 15 miles from the crash site and know a number of people who live within sight of it, so I've reason to pay close attention.)

 

[rkm rdt]

Any sign of Greta?

 

[Gru]

Any sign of Greta?

Not likely. The "green" movement at the celebrity level is all about the green ($$$$),and she'd not be welcome in fly over country anyway.

 

[rkm rdt]

Not likely. The "green" movement at the celebrity level is all about the green ($$$$),and she'd not be welcome in fly over country anyway.

She’ll be at the SVB protest though.

 

[Labslip]

Pour it in a clear container and place it in direct sunlight. This will cure the resin making it sink to the bottom leaving fresh alcohol on top for you to reuse.

This sounded like a great idea. We bought a couple of 1/2 gallon jars with screw-on lids, filled them with dirty IPA and left them in a room with lots of windows (not necessarily in direct sunlight). Three weeks later the jars are full of a kind of gelatin. Nothing has completely hardened and no clear IPA has risen to the surface. We've just got a couple jars of unusable goo. What am I missing?

 

[PRO ARTS DL]

This sounded like a great idea. We bought a couple of 1/2 gallon jars with screw-on lids, filled them with dirty IPA and left them in a room with lots of windows (not necessarily in direct sunlight). Three weeks later the jars are full of a kind of gelatin. Nothing has completely hardened and no clear IPA has risen to the surface. We've just got a couple jars of unusable goo. What am I missing?

We just started doing this.

First we leave the plastic containers in direct sunlight. Then we let the mix of gelatin and alcohol sit for a few days indoors and the gelatin will start to settle at the bottom but still wont harden. Then after a few days we filter it and it separates the gelatin part from the alcohol.

The gelatin definitely still contains a lot of alcohol but at least we are disposing of less alcohol than before. You can leave the gelatin in an open container so the rest of the alcohol evaporates and the gelatin hardens.

 

[adl]

We just started doing this.

First we leave the plastic containers in direct sunlight. Then we let the mix of gelatin and alcohol sit for a few days indoors and the gelatin will start to settle at the bottom but still wont harden. Then after a few days we filter it and it separates the gelatin part from the alcohol.

The gelatin definitely still contains a lot of alcohol but at least we are disposing of less alcohol than before. You can leave the gelatin in an open container so the rest of the alcohol evaporates and the gelatin hardens.

Same here

 

[tuyere]

You can also actively cure the resin at the surface of the alcohol with a UV light; it won't really cure beyond the surface boundary, but you can either agitate/mix the alcohol to expose new, unreacted resin- a magnetic lab mixer is probably the ticket here- or skim it off periodically, which is the approach that automatic IPA cleaning device I posted a while ago uses. IME using a proper UV source to cure helps avoid the Tub o' Goop effect, you end up with a mix of solid-cured film and liquid IPA that separates fairly painlessly.

 

[JKraver]

In my experience the sunlight clear bottle technique never gets close to new clean IPA. I use it for the prewash.

 

[tuyere]

Also that, yeah. I'm pretty sure the dissolved resin in the wash ends up largely oxygen poisoned, just like the permanently-tacky surface of an improperly-cured part. Oxygen reacts prematurely with the photoinitiators in the resin, activating them uselessly and depleting the resin in that area of that critical pulse of reactive free radicals that need to be released all at once to get a thoroughly-cured material.

My working theory is that the liquid in the wash largely blocks the UV of the sun from most of the resin solute, but dissolved oxygen in the liquid continues to react with and deplete the photoinitiators, preventing a proper cure. Exposing the saturated wash to the most direct UV possible is the counter to this, either with a stronger artificial UV source, or exposing more of the wash surface to the UV. I bet you'd get much better results even just using a flat tray vs. a bottle or jug because of the available surface area. Also make sure your vessel material is as transparent to UV as possible or you're gonna play yourself waiting for the UV to get through the UV-opaque container.

Our distillation recycler is very nice because it doesn't have this issue of unreacted photopolymer remnants, it really does come off the outlet hose as clean as when we bought it. Solar-processed wash always needed to be topped up with fresh 99% IPA to maintain its effectiveness, it becomes a worse solvent with every processing because there's clearly more and more unreacted photoinitiator gunk staying in the alcohol each time.

 

[Andrew Priddy]

we stoped using alcohol.. as the main way to strip resin from a print..
we use our Cleanie for plate storage... no clue when the alcohol was dumped last

 

[tuyere]

What are you guys using instead, TPM? It seems interesting but I don't know anybody who's worked with it. The main issue is that it isn't a part of most validated workflows, especially for biocompatible prints.
Alternately- I wish we had enough volume to centrifuge our parts, it's a very tidy way to process models. Shame it leaves too much resin on the parts to work for C&B parts with tight fit-ups.

 

[Andrew Priddy]

Air
from there, it depends on what we are processing


alcohol in a mist bottle is it.. and air



presentation models get processed a little differently...
but our final cleaning involves Dawn powerwash Platnum, and a coat of vegetable oil sprayed and wiped down..
they are not stickey, oily..

the surfaces "that matter", more care is taken... preps, contacts, occlusal.. the rest is fast processing

Rodin Sculpture, more cleaning by hand, less alcohol...

make sure prints are dry from alcohol fully before curing

 

[Car 54]

I thought this was a pretty good video

 

[Sda36]

I haven't really seen this discussed before

What are you guys doing to the used isopropyl alcohol that was used to clean resin from 3D printing?

I have read it can be quite harmful if disposed down the drain or in the trash bin.

If you place your old ISP alcohol in direct sunlight it will further cure and deposit old resin to the bottom hence you can re-use isp, just siphon of the good and discard the minimal sludge. I've seen a recommendation to add 25% more ISP to that mixture after that process.