An update on my tray experiences:
A squeegee is a must for cleaning the PDMS! I just cut a piece off our the squeegee we use at home to clean windows...you'll want to snip two pieces off; one from each side of the squeegee so your significant other doesn't notice there's 2" missing from just one side ;)
I noticed there's trenches on the two longer edges of the PDMS, so it's best to squeegee along the shorter edge of the PDMS.
I like to put a few drops of acetone on the squeegee and then dragging it across. So far, acetone hasn't had the same peeling effect as Isopropyl on the PDSM adhesive. However, if you drag too much across the PDMS and it pools around the acrylic tray, you'll get some serious tray hazing. I haven't found this to be too detrimental to the print though!
I've also had great luck with Rain X! I treated one new tray with it by dumping about 25ml in the whole tray and creating a vibration effect with my hand. I then dumped the same Rain X into a heavily used tray. The Rain X did a great job of cleaning up the cloudy PDMS window in this tray! I repeatedly used a squeegee on the PDMS window while the layer of Rain X was sitting in the tray. Again, no issues so far with the Rain X eating away at the PDMS adhesive.
So, the following are definitely "must have tools" for caring for your trays:
- Rain X
Overall, I've had very bad luck with any cloths on the PDMS. Even the most lint free / smoothest clothes seem to either stick or introduce some fibers which really get embedded on the PDMS. I find the squeegee really is best, followed by fogging with your breath...and repeating as required.
I'm still experimenting though, so any tips are appreciated!