Re: repairing leaks and putting new fabric on seats
If you need to bolt a vinyl-covered item to the boat hull, there are only two ways I can think of. One way is to bolt or screw through the vinyl, and ise a stainless steer finishing washer to dress up the fastener. You can also buy snap on caps for bolt heads. These caps can match the color of the vinyl.
The other way to fasten a vinyl-covered piece to the hull is to install a stainless steel bolt to the piece with a Tee nut, prior to covering it with the vinyl. The tee nut holds the bolt in the object, but allows the bolt end to stick out. Now the piece is covered in the vinyl, which hides the bolt head. The bolt end is placed in a hole in the hull and a washer and nut is installed on the backside of the hull to hold the piece in place. This method only works with thru bolted items, where you can reach the back side of the mounting area.
