1.Drilling? I will go with what Knockoff said cover the gel with masking tape,,the masking tape makes it easy to lay out your hole patern and as long as you use sharp bits you should be fine.
2. I think the backing material was covered very well in the link Knockoff posted.
3.Drilling through the transom,,if you have to drill through the transom keep in mind that most of them still have wood cores so if water gets to them they will rot pretty fast,,so if I have to put a hole through the transom I will treat the inside of the hole with wood sealer and then put a nice silicone seal around what ever goes through it,,and check the silacone once a year to make sure it is still water tight...the same goes for anything you mount to the floor! water tight!
4.As for electric's, what ever you use for connectors try to keep them water tight to keep corrosion at bay,shrink tube can be a big help.
Avoid wire rubs and if the wires pass through any holes in glass or aluminum, a rubber grommet is a nice touch and it will keep the hole from cutting into the wire over time.
It is also a good idea to run the wire for you electronics down the opposite gun away from you motor wiring so you don't get RF NOISE leaking to you fish finder
2. I think the backing material was covered very well in the link Knockoff posted.
3.Drilling through the transom,,if you have to drill through the transom keep in mind that most of them still have wood cores so if water gets to them they will rot pretty fast,,so if I have to put a hole through the transom I will treat the inside of the hole with wood sealer and then put a nice silicone seal around what ever goes through it,,and check the silacone once a year to make sure it is still water tight...the same goes for anything you mount to the floor! water tight!
4.As for electric's, what ever you use for connectors try to keep them water tight to keep corrosion at bay,shrink tube can be a big help.
Avoid wire rubs and if the wires pass through any holes in glass or aluminum, a rubber grommet is a nice touch and it will keep the hole from cutting into the wire over time.
It is also a good idea to run the wire for you electronics down the opposite gun away from you motor wiring so you don't get RF NOISE leaking to you fish finder
