How I distill my used IPA

I’ve tried that also but it doesn’t work for me. also you must not use a lot of IPA as I do. I go through about 4 gallons a week. I’d have to have a couple dozen trays laying out side to even dent what’s needed to be disposed of.
I do remove the sludge from the still and put that in clear plastic bags. Those go into an aluminum turkey tray and set outside in the sun for days to harden.

Been using a resistive hot plate to heat the same still. Cooks out a gallon of good clean IPA but then the output invariably starts running yellow. Upon opening the unit later I find that it has burned the resin to the bottom of the inside of the pot. Thinking of switching to an induction cooktop as you specify in your document, but the boiler pot on my still isn’t magnetic. Minimum heat setting of the resistive hot plate is somewhere between hot lava and thermonuclear.

You can’t run the still dry. That’s when the sludge hardens. Stop well before, drain the liquid slowly so you don’t get the settled sludge. Scrape that into a plastic bag and put in the sun to harden. Clean the still pot and start over.

1 Like

The Safeway to do it is use a distiller in a well ventilated room that you can purchase on Amazon.com. link below.

Google says IPA boils at 82.6 °C.

I am not sure, but I think I used to use 85 °C, had to buy a new distiller as the old one stopped working. Waiting on a friend to confirm, but 85 °C should be safe. Do not turn the heat up to speed up the process as that is extremely dangerous. 100 °C (boiling for water) if you want the water as well. At 85c you will mostly get ipa, at 100c you would get the water and ipa. If you use 70% ipa, then set the temperature to 100c.

What you have left after all of the IPA is distilled is a watery slush of print resin. If you remove the water, it will likely be baked onto the bottom of the distiller pan making it very difficult to clean. If 70% ipa works better for you, then if you distill at 85c, you can clean the distiller better, then add 30% distilled water to you near 100% ipa to make it 70% again.

I purchased a silicone tube and attached it to the outlet tube of the distillers condenser about 1.5 feet. I would let it drip from the counter to the floor onto the outer side of a large aluminum funnel so the ipa would have to run down the funnel using the funnel as a heatsink that I would sit in top of a gallon ipa bottle. To ensure the ipa is at a safe temperature, I would use a small fan to blow on the outside of funnel to cool it down.

This is the safest way I can think of to do it the scientifically proper way. Once you use the distiller for cleaning your resin print wash ipa, only use that distiller for resin wash ipa reclaiming.

End result is a clean bottle of ipa. Once done let the distiller cool overnight and then scrap out the old resin into a bowl you do not need, old plastic or old noodle bowls work great for this. Place outside in the sun until completely dry and cured, then dispose of properly.

Amazon Links:
Distiller:

Aluminum Funnel:

Silicon Hose:

Fan:

Wikipedia says that IPA forms an azeotrope with water and the azeotrope boils at 80.4 °C and that the azeotrope contains 91% IPA and 9% water by volume. You might want to consider that in your distillation plans.

This what we use https://solvent-recycler.com/

It works quite well

2 Likes

How much does it cost?

A lot. I don’t remember exactly. $4-5k. It’s been about 3 years. It just paid for itself now.

All great info!

I’ve been distilling for the last two years (actually just in summer…more on that in a sec).

I have what is touted as a “high end” hygometer that tells me I’m between 97% - 99% under the perfect circumstances. It’s taken a while for me to get those perfect circumstances, but here’s how I do it:

  • Make sure the distiller is CLEAN! Especially over the heating element. This is critical. Resin can easily adhere to this area
  • Make sure your IPA has “settled” and any pigment is at the bottom of the container
  • Slowly pour into the distiller until you get to the pigmented part. Let that part just evaporate/cure in the sun
  • Use a garden hose and connect that to the condensor. Let the drain run into the yard. It sounds wasteful, but you don’t need a high flow. Just enough to take the heat away. Or, use a chiller (I haven’t tried this yet).
  • In Minnesota, I can only do this in the non-winter days as I only do this outdoors.
  • It takes about 8 hours to distill 8 gallons. After distilling, once the distiller is cool, you can scoop out the ‘snot’ (it’s pretty gross). I’ve been putting that in a separate bucket and let it cure. In the summer that takes a couple days in direct sunlight. Once cured, it easily comes out of the bucket.
2 Likes

Thanks for the insights, @SteamFactoryLLC