Depends on what you are referring to...

For the most part, I used solid rivets to attach angle aluminum to the hull, and then screwed the plywood to the angle.

In some places, I used stainless bolts/washers/lock nuts.

Around the perimeter of the plywood, I used polyurethane adhesive to create a solid bond with the hull.

The end result has been a rock-solid hull. Very little flexing or banging when I go through rough water at high speed. Just "thump-thump" and I'm through it.

-TH