Recover your IPA

When my IPA reaches a certain saturation point, I remove the strainer, cover the cleaning tank and set it in the sun for a few hours.  The dissolved resin begins to precipitate and turns the IPA cloudy.  I then make a large filter out of a good paper towel and filter the IPA into a quart container.  I have done this several times with good results.  I then clean the tank, strainer lid and gasket with fresh IPA and refill my squirt bottle–ready for another run!

I tried coffee filters-just too slow.


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Thanks Brad for sharing.  I’ve been trying to figure out how to reuse the IPA as I have been using quite a lot of it.  I’ll give it a try and post my results!

Nice tip, thanks!

I stuck my alcohol bath out in the sun and the result is in the attached picture.  Filtering is not an option at this point.  I was very surprised that there was so much dissolved resin in the bath because it looked fairly clear before I exposed it to sun.  At this point, I’m letting it sit out and it is slowly solidifying.  I’m hoping it will eventually harden so that I can dispose of it as a solid.  I think the lesson here is to filter the bath often- this is the result of close to 3 months worth of rinsing.  Anyone have any suggestions or similar experience?


Wow, that’s intense! I’ve only been printing a week, but already swapped out my IPA. I’m going to put the old batch in the sun and I’ll let you know how much I get out of it :wink:

That doesn’t look right. Do you like pour your excess resin from your tank into your alcohol bath?

I cleaned my IPA many times already and did leave it under the sun, but never with results like that.

I got cotton ball like clusters that easily broke up when disturbed. That looks like you had an immense amount of resin in your bath!

Was thinking of using something like a fish tank filter system with hard UV to quick cure the resin. Any thoughts on how much exposure or intensity is needed to do this?

You might tray a Harbor Freight halogen work light with the cover glass removed.  I figure everybody has one of those kicking around.

As a follow up to my earlier comment and photo in this thread (from September), I’m including an image of what my alcohol “bath” looks like now.  The container has been sitting in our offices in the sun by the window for about 4 weeks.  It’s not an ideal way of managing the rinse bath, but at least now I can dispose of the residual solid resin fairly easily.



Was the container covered all that time or has the IPA been completely evaporated?

I left mine out in the sun, sealed, longer than planned (figured if a few days was good, a week would be great…)

I also found coffee filters don’t work on IPA at all.  Must be some treatment on the filters or something, I put about an oz. of 91% (what was left of liquid from the attached blob,) and after an hour it hadn’t visibly gone down at all.

For those that don’t know, an easy way to make a non-leaky cone out of flat paper is to take a squareish piece, fold left to right, fold top to bottom (so you end up with a square again,) and pull 1 sheet away from the other 3.  Will be 3x as thick on one side as the other, but works great and takes 15 seconds.

I bought a cheap distillation kit from ebay $45AUD but you can get them up to 1000ml. Mine is 500ml,24/29,Glass Distillation Apparatus,Laboratory Chemistry Glassware Kit Good enough to boil the IPA (85 degrees or so) but DO NOT USE A NAKED FLAME…also has a breaking bad vibe about it. Doesn’t take long to boil out into Liebig tube (running cold water across it to cool down condensate) and capture 99% IPA at other end with crap left behind. I haven’t got photos but will add some if I have time.


(@PatrickReid I’d love some photos of that!)

I’m in the UK and we get zero sun right now :frowning: do you think if I just left the IPA out in the daylight for a few weeks the resin will eventually cure?

Is it possible that if the IPA is so contaminated with resin that when you put it in the sun or a concentrated UV exposure the liquid resin will bind to the IPA and therefore mix to a Jelly? therefor leaving little IPA to recycle?

Edward- I found that if the resin gets too cloudy, filtering times reach a point of diminishing return. Try filtering more often to keep the IPA fresh. Too much resin in saturation means longer bath times too.

Sounds weird but I was wondering if you could run the IPA through an activated charcoal filter (brita water filter). I’ve seen an episode on Mythbusters about filtering alcohol.

That could work. At the moment I’ve put a large glob of the jelly on top of two paper kitchen towel. The IPA seems to be dripping out but takes a long time. I also need to leave the jelly stuff and IPA soacked paper towels outside for a few days for the IPA to evaporate as I dont feel safe throwing it in the bin.

I think the lesson is to clean the IPA once a week or two weeks. Also I recommend pouring it into a throwaway plastic cup and sticking it in a cure oven. If there is jelly its an absolute nightmare trying to clean out.

My setup at the moment has my IPA vats in the sun all the time. The resin precipitates out within a day or so after doing a rinse. It just collects on the bottom of the vat and once in a while I filter it. I’ve been using white resin, don’t know if it clumps more than the clear (the big blob I posted over a year ago was clear.)