What would cause IPA to turn to GEL

I’ve been using a 91% IPA for rinsing my finished prints. I’ve had it in the UV Curing Box before but this time, after an hour, it turned to gel.

There isn’t anything listed on the bottles and I question if the FormLab’s resin would cause this. Just puzzled about it and now I have a mess to clean up.

I’m using Grey Ver. 2 ONLY.

  • Walt

Looks like you’re not the first (near the bottom theres a picture):
clicky

There wasn’t much of a resolution in that thread… seems to just be fully saturated with resin.

Exactly… How many times do you rinse a (new) print in it before changing it? Note that IPA slowly dissolves over time as alcohol is volatile. This means that the longer you wait the percentage resin/ipa changes (more resin vs less ipa). Eventually being saturated and curing it will result in these kind of issues. The picture in the thread @Paul_Schommer is showing is (in my opinion) an extreme case.

Well, I was going with the idea that you hardened the resin in the IPA by putting it in the UV curing chamber then pass it through a fine mesh paint filter to get the plastic out. I do very small pieces and had only done this twice before mine looked almost as thick as Paul’s did.

Evidently, recycling the IPA is only once or twice at the most.

  • Walt

The only explanation I can think of is that you’ve saturated the IPA with resin, and the resin-in-suspension cures in to a rubbery matrix when exposed to UV. There’s no way I can think of for the IPA itself is turning in to something gelatinous. Not without some serious outgassing… but regardless of what causes it, it’s really cool. Put it outside in the sunlight and see what happens. Perhaps you’ve invented a new way to make aerogels!

Randy, I’m sure you are correct. My prints are small so I may do eight to a dozen items at a time and as they generally don’t take more that two hours I may run four prints a day.

Looks like I need to UV cure the IPA once a day to see if that works. Also, as the first rinse tank of IPA goes bad I will pour that off and then pour the second rinse tank’s IPA into the first tank. Then fill the second tank with fresh IPA. Feel this is a better way to get the most life out of the IPA.

I also found that the gel does evaporate off. After pouring out the majority of the gel into the old IPA bottles I turned the tank upside down on a shop towel. Next morning there was little trace of the gel in that tank. So, as soon as the sun is out, I’ll put the bottles of IPA/Gel out in the sun and let them evaporate off. Won’t have to mess with disposal that way.

  • Walt

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