Cmposite stingers?

[Okieboatguy]

This is just a general question and a hunt for information. Has anyone thought of using the composite decking beams for stringers? I was looking at them over the weekend while helping dad put in his new deck. It came to me that they may make a good stringer. They would never rot, and the price is not over the top. I was just wondering peoples thoughts?

 

[tpenfield]

Re: Cmposite stingers?

Generally the depth of a stringer that you would get from a decking board is not quite enough, except for fairly flat-hull boats. You would then need to do a full fiberglass encapsulation of the stringer, as adhesion would be questionable with merely tabbing in.

So, a better approach for synthetic stringers would be to use urethane foam as the core and full glassing at adequate thickness to form the stringer.

that is essentially what the boat manufacturers do . . . the ones that do composite stringers.

 

[idonthaveaname]

Re: Cmposite stingers?

From what I have seen on this forum most will say no. The reason is they are typically not rigid enough. They are also expensive. Most will tell you to use plywood and fiberglass encapsulation which typically works the best. That's what I used and it worked great.

 

[Okieboatguy]

Re: Cmposite stingers?

The rigidity issue was my main thought, but they come as 3/4" X 6" x 16' and if you strip 1 beam to 3" wide, then you could use epoxy to glue them back to back and staggered to what ever height you need, with a total thickness of 1.5". The cost is about $25 per board, and the backs have ridges, so if they were epoxied back to back they would interlock and add rigidity and gluing surface. Take into account the cost of encapsulating wood beams, less installation time on the composite, and the durability of the composite I am still wondering if it is something worth looking more into. Anyone know of what type of epoxy to glue them with, maybe PL? I may just go buy one today and try some experimentation with it.

 

[Yacht Dr.]

Re: Cmposite stingers?

You know .. there was a time in my life that we started using synthetic boards around the horses.

Basically the horses would sit there and chew anything that was wood.

There was a product that the horses would not munch on ..

After thinking .. I might suspect that the properties of these "boards" might be utilized in boat building .. but I have not had the time to research these things.

YD.

 

[saginawbayboater]

Re: Cmposite stingers?

A sheet of aruaco ply is $40, and a simular quantity of the composite would be $100. One would still need to encapsulate, and tab. The strength of the stringer is not in the bedding. The strength comes from the laminate, and the tabbing, no? :noidea:

 

[Woodonglass]

Re: Cmposite stingers?

If you apply enuf glass then yep the wood is just the form, but two layers of glass is not enuf. You need the span strength of the wood to help too. that's the other main issue with the composite deck material. I has very little span strength when placed on edge. Epoxy will NOT adhere to it very well. To much flex in the material. Dimensional lumber or plywood is still the most cost effective and best material to use. This topic has been discussued a lot on most of the popular boat restoration forums and this IS the concensus of most of the builders. Based on what I know about the material from a construction stand point, I would have to agree.