Time again for another Update.
Here's the finished, carved foam Template.
The next step was laminating a short tube, using a stainless tube as plug.
That tube will be inserted into the tank as tunnel, as I'm planning to mount some switches into the tank.
Then the big job started.
At first I've wrapped the foam in a thin plastic foil and then waxed that foil.
That prevents the Epoxy from soaking into the foam and gives you a smooth surface on the inside.
After the foam is washed out, you can just peel off the foil on the inside.
I've laminated about 6-7 layers of glass mesh, using epoxy reason.
A filler cap flange, mounting brackets and a hose flange have beem laminated in.
These have just been placed between the layers and all these parts have a perforated section which bonds with the FRP.
After everything has dryped up, we ended up with a very rough surface.
A lot of grinding was required to get everything into reasonable shape.
There are still some imperfections which I need to repair, before the part can be fillered.