Time for that viewing port in the top hatch piece. I nearly called it a night after working all day on the bottom mounting ring but decided a bit of a push and I could get this curing tonight.
Pic 1 is after quite some cutting, filing and sanding on the top piece to make a 3" X 2" view hole. Then I went at it measuring my view port size and adding about .8" around the edges. I got out my dremel router and knocked about 2.5mm down in 6mm PVC to make the view port.
Now I was going to place it with the flange on the outside but after testing the PVC to aluminium bonding (22/5/17 log) I much prefered the neater option of doing it as you see in pic 3.
Pic 2 shows me floxing the window in with a roughened aluminium surface and prepped PVC. Interestingly there are a couple of small air bubbles which would be unevenness in the glass but I can see that the flox is making a seriously complete bond and I'm happy.
The pic 3 result has a slightly resessed window. Perfect. In service I might just put some tape over it to protect the PVC and just do an occasional check to ensure my hydromat filter in the tank is not getting clogged.
