New stringer planning help needed

[NWLundguy]

This is a 16 foot runabout restoration. I spent most of yesterday grinding away the old stringer tabbing, and am trying to figure out the new structure. The OEM had two 2? x 3? suspended off the hull with the tabbing, ?? plywood deck, poured foam. I wasn?t planning to use poured foam, so do I need more stringers to help stiffen the hull? Lots of work to get all four stringers level if they all contact the floor. Maybe two of the stringers aren?t full floor height, just glassed over stiffeners? Seems like a few bulks, one at each plywood joint (3 joints) might be in order too (?). Or, use poured foam again? I can see the value of poured foam because it does provide twisting rigidity, floor support, and hull stiffness. The floor width at the widest point (transom) is 58 inches. Head scratching going on ? ideas and advice welcome

Thanks for reading

Brian

 

[oops!]

Re: New stringer planning help needed

hi brian....welcome to i boats

stiffening the stringers will not take the place of the foam. it will just stiffen the stringers.

i am actually really beginnning to see the benifet of foaming a boat....so i like it.

however....if you dont want to foam the boat....the glass should be stiffened if it is weak.

(if the glass is really wobbly and easy to press in or push to make it bow),

i would add 2 layers of 1.5 csm thru the hull or one full 1708.....but that is alot of weight for a 16 footer........again...it is easer to foam.

if you do foam.....just make sure you drill in proper limber holes so the water can drain thru the foam.

 

[Friscoboater]

Re: New stringer planning help needed

I am a foam believer too, and I will be putting back into my boat. It helps alot if done right.

 

[proshadetree]

Re: New stringer planning help needed

I have heard many say that Baylinners need foam for structure. I did not re induce foam into my build. The boat has been done for 3 years and I have had absolutely no issues. I boat on inland lakes. If I were to boat on the open water or a lake that I can not see the bank at all times I would re-foam the boat. I have had no handling issues and no cracking I have about 75 hours on her. I say the choice is yours. Just rebuild like original and omit foam or build compartments under the deck that act as jets if the hull is breached. I left drains at lower ends of my compartments to only allow x amount of water to pass.

 

[NWLundguy]

Re: New stringer planning help needed

Thanks for the advice guys. I think the boat is a good application for poured foam, and so will use it. The hull is a combination of hand laid matte and roven, and is approximately 5/16" thick, but does deflect under foot, now that all the tabbing is gone. The bottom hull shape is a shallow V, so the rear stern half is pretty flat, and the foam against the hull will provide support and sound deadening. I will take every precaution to install all deck fasteners properly, to insure long term integrity of the bilge cavities. The boat is 39 years old, and was in pretty good condition when I tore it apart. The failure came from the rusted out screws and bolts (common steel) that held down the fuel tank, and the bolts that hold the steering cable bracket on the transom.

Onward!!!

Thanks again