IPA saturated with resin?

I print about 1L per month worth of parts and replace my IPA bath about that often as well. I soak my parts for 1 min then put the parts in IPA in an untrasonic cleaner for 5-10 min to remove uncured resin. Works great.

This time I went to dispose of the old IPA and found it swamped with what I assume is partially cured resin. Obviously not usable I am now curing the resin out but has anybody seen anything like this? Its like the IPA is saturated with resin but I have no idea where all this resin could have come from. Thanks.

I’ve had that gunge effect when either water is added or exposed to strong sunlight - as you surmise is just the resin in solution reacting. I filter my IPA using kitchen towel and 150 micron paint filter and it means I don’t have to replace the alcohol as often.