Hi PE et al,
I tried a piece of the Melinex 535 that Denise sent me. Was able to make a very nice, smooth coating with test gelatin. After letting it dry for about 3 hours by my portable heater, I soaked in room temperature water for 45 minutes (give or take a few) with no lifting, frilling or visible change. No green food coloring in the water.
Also coacted a piece of subbed and unsubbed 35mm triacetate (according to the datasheet) salvaged from an exposed piece of ORWO UN-54 after removing the emusion with bleach. Upon soaking in room temp water, the unsubbed piece lifted immediately, the subbed piece survived 15 minutes without incident, at least to my eye. This was using the acetic acid subbing from Kaszuba's patent.
I would say it's a combination of the diacetate material and the subbing folrmulas. Something in the gealtin coating step is preventing proper adhesion to the diacteate. As I mentioned above, subbing by itself (visible by red food coloring) seems to adhere OK. Once gelatin is applied it lifts within seconds. My only guess is that the chrome alum does not work as a hardener with the diacetate. When I get glyoxal some day I will try again.
Someday I will return to this, but for now I'm using the Melinex or 3M material, which also appears to perform as well as the Melinex.
Thanks for everyone's help. I've still got about 250ml of emulsion out of the original batch waiting to be coated and exposed!