I was preparing to upload some update and pictures about my panels I am currently building...
We were building the panels like NICE (search the web)project suggests (the same principle as double pane insulated windows). We were using double tempered glass (front and back), alluminium hollow square pipe to hold the "silica" inside, to prevent the condensation, glued with SIKA Tack drive car windows glue, alluminium profile 20x20x2 mm (U-type) to hold that all together.
We sold some panels to the guy that mounted them onto te boat, and after a while he called us to inform us tht the panels are wet inside. We went to see what's happening, and it seems that the SIKA glue (silicon) wasn't thick enough, and that inside pressure "blow" it from between two glasses.
We tried some other things when repairing those panels, and after many trials and errors we can say it's all OK for a long time now.
Now, we use double glass (tempered, 4mm each), 3x3mm rubber glued to the glass with adhesive butyl rubber (both side adhesive, it uses in window making industry) to glue the glasses to the rubber, SIKA Tack drive 8mm deep between the glasses (it gets 11 mm in total inside the glass- 3mm rubber and 8mm SIKA silicone). After we leave it for a dy to stay and dry, we apply ARGON (Ar) gas inside the panel, to ensure no condensation appears. We apply plenty of gas, more than it's inside of the panel (6 l/min applied for two minutes - x2 (two times)). We take two bus bars outside the panel between butyl rubber and 3x3mm rubber, and after we glue it all together, it simply cannot leak.
We teated the panel with the internal pressure for more than 1.5 Atm (Bar) and nothing happens. We test each panel for condensation so that we put it on total sunshine for a hour or so and after that we throw plenty of cold water on the upper glass. After many errors and condensation, it seems everything is OK now.
Here are some pictures of error panels, as well as two ones we finally installed on the boat: