Putting decking in tinny

Hi guys I'm starting a project this year on our savage 3.8 meter tinny just need some help on the decking and how to mount it.
What wood do I use?
How do I mount do I weld beams then screw the wood into that?
Thanks I'll give measurements tomorrow.

 

There are numerous ways to accomplish this. It would be helpful for you to post a picture of the existing boat and explain what the deck will be used for.

I built a lightweight deck for an aluminum boat using 1/4" plywood, a single layer of fiberglass, and three 1 x 4 stiffeners. I bolted a rubrail around the edge to bridge a gap; mine had a formed edge not parallel with the deck. Mine was built only to shed water and support one person using it to hop onto a higher landing dock.

 

For a 12 foot tinny, you will want to go as light as possible, as any high up weight is siginificant.

Since you are in Melbourne - I would consider a trip to Port Phillip Plantation Shutters, and get some Pawlonia ( Kiri ) strips to glue into a suitable shape, and then glass them like FMS did.
http://www.paulowniatimber.com.au/

The timber is a little bit more expensive than marine ply, but weighs like balsa, and withstands weather like Huon Pine. It would like great in clear finish if you wanted to go to all the trouble.

 

That's the boat it's a 380 snipe

 

How about a shot of the bows, and an indication of how big a deck you want ?

 

He just wants something flat to stand on, rather than the uneven pressed alloy bottom. Usual procedure would be a sheet of ply, notched so it fits around the ribs, and can't slip around too much. What is more properly called the "cockpit sole", rather than a deck.

 

Na I'll get my measurements now and make a scale model out of cardboard and see how it goes. I was thinking of welding stands on the ribs so I can drill the play wood into.

 

You don't need to weld anything, a 900mm wide sheet of 12mm+ ply should suffice to give you a flat area to walk fore and aft without stubbing your toes, you dont want anything high in a little boat like yours, certainly not as high as the chine level.

 

Yes indeed, and make sure its removable for cleaning.

Accumulation of grit and sand is the biggest danger for aluminium hulls, and you need to be able to clean it easily.