I have a valiant DR 490. I am informed that the deck of this ribs is firbreglass with a foam core. Most ribs are plywood deck with a fibre glass covering. I am trying to figure out a way of storing dive bottles on this rib. I am of the opinion that a standard bottle rack screwed to the deck will not work in this case due to the construction method of the boat.
I believe that self tapper screws will pull out of the deck as there is no strong structural elements to bond with.
If 'twere I, I would put some matting down to protect the deck from tanks and weights and then put 'em on something to stop 'em rolling. Maybe a sack with some polystyrene "peanuts" in it. They'll not go too far.
I had one made similar to a style that XS use for my Ribtec 585. It was just 2 horizontal bars secured to the A frame just above the deck and about transom height with bungee loops to go around the pillar valves.
Drawback is that your cylinder weight is right at the stern but if you trim up carefully with people and weight belts it worked well. It keeps the deck space fairly clear too.
I do have some photos at home somewhere if that approach is of any interest.
Mick, my DR750 has a dive rack fitted from the factory. They put deck hatches at each end in order to access the nuts for the bolts that secure the rack. My deck is ply sandwiched as you mentioned. In your case might there be an option for you to to fit hatches, then scoop out a section of the foam filling? You could then plane up a piece of timber to place in the scooped out section to form up your own sandwich section.
First time uploading photos but I've tried to put a couple up with the rack and clamps used for fastening to the A frame.
As you can see (hopefully) I had the rack come forward a little to give space behind it for storeage and Aux fuel tank, which were all secured to it. Cylinders stood in front. Of course how far foward or back you have it depends on available space and where you need the bottles to sit.
ps if the pics don't load up PM me with your details and I'll email some
Clewless
Eastern Thunder
Northern Exposure 5
Managed it. Nice system Ribnet even I can manage to use it
