Read up on varnishing. Many prefer to start with two coats of epoxy, then varnish. That will seal the wood. As you saw in my pictures, I removed all the teak anddid the job at home. The screws in my boat were 2 1/2" with a finish washer and screw from inside. The hatch wood I screwed down also using finish washers. Except for the hatch handle, i left all that teak out. Looks cleaner that way.