My Outer Island has 6-oz. cloth on either side of the deck, and I added one extra layer of 6-oz. to the underside of the hatches. Jay's instructions were for 3 layers of 6-oz. on the underside, and I don't know if he meant in addition to the full inner deck layer or not. With 2 layers on the underside both hatches are plenty stiff, and I have knob-closed hatches which have a very strong clamping force -- both stay perfectly dry. The front hatch is a 10" hexagon, the rear is similar but stretched to ~12" long.

I would just put one layer of 6-oz. on the underside, fill the weave around the edge for a good seal, and call it good. The knob-closed hatches pull down hard on the center of the hatch. Your (Ross') system pulls closer to the edge where the force is needed, so you will probably see less bending stresses in your hatch lids.

Dean

: I'm using Ross's internal hatch holddowns method on my Expedition Single. I'm
: about to glue on the hatch hooks and wonder if I have enough glass on the
: hatches before I proceed. I have 1 layer of 6 oz.on the outside and 1
: layer of 4 oz. on inside. The hatches are oval and are average sized. The
: internal system may apply more stress than external straps or bungees. Any
: ideas appreciated.

: Thanks,

: Larry C.