Stringer positions and design -stejcraft

[Benzo87]

Greetings team,
Long time reader first time writer.
I have been gifted a 1994 Stejcraft stallion 16ft hf cabin, the boat is complete and for the most part in good condition however the rear of the cover was unknowingly torn for 2 years before i aquired it and so the rear seats along with the deck and unfortunately the stringers have all rotted.
I am almost finished cutting out the old floor and about to take my first attempt at any sort of fibreglass boat repair, i have however been attempting to accumulate as much knowledge as possible.

Regarding the stringers, the current stringers consist of a central keel stringer and 1x side stringer on each side aprox 300mm from the keel striger. They appear to be a little on st slim side at only 18mm EXCLUDING the fibreglass.

The keel stringer currently stops just short of the transom by about 30mm to allow room for the bung plugs and tapers down at the last 300mm to create the decking drainage well.

I have 3 main questions:

1. Will the boat benefit from connecting the keel stringer to the transom or is the fact that its glassed so close enough to add a structural element. I would need to relocate the bungs or create a 'bridge'.

2. Now as we all know, plywood does not come in 5 metre sheets. I know i can lap joint the stringers to make them the correct lengths, but since i already have some cut and laminated to thickness from when i assumed the floor rott was only a third up the boat, is it acceptible to put a crossboard (bulkhead) in a third up the boat and then start new stringers on the other side?

3. if i wanted to make a storage well in the centre, could i stop the keel stringer at the well, with said bulkhead board and run 2 stringers either side of the well and then back to 1 where it finishes?

Have added diagram and images.

Many thanks
gav

 

[Benzo87]

bump...

 

[Scott Danforth]

The center stringer is short to have a garboard plug

The bulkhead may be fine with enough tabbing. However I am not a naval architect. How this is the hull at the keel?

You have a lot of items in the boat to remove prior to going farther. Pull all the interior bits.

I highly recommend making a cradle

You did remove and de-rig the outboard, correct. If not you want to do that ASAP.

 

[Benzo87]

Boat has now been mostly stripped out, and flopr almost completely removed. I think i will just continue with the original design of a straight through keel, however i will be adding extra cross supports ad the existing ones where pretty pathetic. Id like to ideally make the stringers out of solid timber rather than marine ply so that i dont have to lap joint or glue and screw the layers. Ive been doing a bunch of research but there is so much conflicting info about timber types for stringers.

Thank you scott for the suggestion of making a cradle, i had not though of that, i will have to make one that sits around/bolts to the trailer as i have nowhere to store the trailer during the build.

 

[Scott Danforth]

Ply wood is significantly stronger than dimensional lumber.

You can use poly foam if you want for stringers if you add enough layers in the encapsulation

You can build a cradle on the trailer if needed