Guidance with install of thru-hull on 11 meter express

[7421f]

I am adding an additional bilge pump and knowing that I have a cored hull, I would like some advise on the proper way to do this. How far does the cored section of the hull extend above the waterline? Would I be drilling thru glass only, and if not, what is the proper way to insure hull integrity when installing the fitting? I am looking to install the fitting 6 to 8 inches above the waterline, like the factory ones. Anyone else tackled this on your 11 meter?

[Big D]

If you drill into a cored section, dig out the core all around the hole 1/4 - 1/2 inch deep then fill with thickened epoxy. If you go 1/2 inch deep, carefull not to make the mix too hot or fill just 1/4 inch first, let it cure for a few hours, then fill the rest. If you fill too much at once and the mix is too hot, it will burn. You could also use slow curing epoxy and not have to worry about it as much. Once fully cured, bed the fitting in with regular Sikaflex or 4200.

[P-Dogg]

dig out the core all around the hole 1/4 - 1/2 inch deep

An Allen wrench in a drill can be useful for this task.