Time to setup another test. I am trying to create a dam wall for the silicone coated VAT, that I have not yet built. I will have details on the experiment with glass and different foil in an attempt to create a thin coating of silicone on the VAT glass.
I have found an aluminum I-beam with unequal sides. One side is 7mm high and the other is 5mm. Width is 17mm. I filled the channel with silicone and let it dry for 3-4 days outside (still relatively warm here - 24C during the day). It solidified and used an exacto knife to separate the sides and lift the silicone.
I used a business card to smooth the silicone while still wet. Put it in the pipe from the lens assembly spacer post to keep it from dust.