This week while in Florida someone asked what we used to get the wires thru the fiberglass shell of the Scamp
. I'm sorry but I do not remember which thread it was nor can I find it.
We used the Glomex fitting RA-140.
Glomex - The best in Marine Antennas - GAMMA PRODOTTI
Drilled a hole through, fed the wires and filled the fitting with Clear Lexan. We then screwed the fitting to the roof with stainless steel screws.
I believe we installed this 3 years ago. It has never leaked.
As an aside, we used Scotch exterior high bond strength tape to hold our panels down. They are still in place after over 20 months on the road. I know that the Scotch is not the most expensive or 'stickiest' but it has worked well for us and is not expensive.
We also use the Scotch for holding plastic cabinets to walls and on the smooth fiberglass walls of the Scamp
they have held up perfectly.
We did not run any other sealant around the edges of the solar panel
to protect the tape from water as was recently posted.
I hope this helps who ever asked.