
Posts: 1663
Location: Kodiak, AK | Start small, as in with a pilot hole and gradually work up from there. If you try to take too much too soon or all at once, the bit can (usually will) grab the gel coat and either crack it or break off a chunk. Some guys tape it off first, putting down masking tape (not duct tape!!) to help thwart cracks or breaks.
For the trolling motor, I recommend bolts. For the transducer, I recommend screws. When drilling holes for screws, you've got to find the happy spot. Make the hole too big, and the screw won't bite. Make the whole too small and you'll posssibly crack the glass screwing it in. It should screw it with some resistance, but if it's hard to screw in, it's too small and you need to back it off before you crack the glass. |