What is the hull made of?

[robert843]

So after some research I have not found the answer I'm looking for maybe someone on here knows. After being at the boat show most of the offshore builders were very proud to go into their details about hull construction what type of stringers they use, materials, how much foam fill and process and why there hull is better then others. I have tried to search and find out but does anyone know what type of stringers Yamaha uses and what materials at what thickness? Also did any of the specs change from 2014 to 2015? I do believe that most of the offshore companies are making a more rigid hull then the Yamaha's but what makes that difference is really what I'm trying to figure out.

 

[Speedling]

Outer hull is just fiberglass.
Inner sections, floors, etc are ply with fiberglass encapsulation.

 

[swatski]

So after some research I have not found the answer I'm looking for maybe someone on here knows. After being at the boat show most of the offshore builders were very proud to go into their details about hull construction what type of stringers they use, materials, how much foam fill and process and why there hull is better then others. I have tried to search and find out but does anyone know what type of stringers Yamaha uses and what materials at what thickness? Also did any of the specs change from 2014 to 2015? I do believe that most of the offshore companies are making a more rigid hull then the Yamaha's but what makes that difference is really what I'm trying to figure out.

I always assumed it was FRP. @CrankyGypsy did some major work on those https://jetboaters.net/threads/how-to-beginner-frp-repair-in-the-driveway.8184/
I think the 2012 and the 2016 (that I have drilled through) have the same hull material.

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[robert843]

Are there no stringers used?

 

[swatski]

Are there no stringers used?

Stringers are glass I believe but have some small plywood pieces (glass encapsulated) for holding screws and the like. There is plenty of wood in all the lid/hatches, in the floor, plywood for bulkheads in engine and battery compartments, and behind the cleats and handles.

All the fasteners in the bilge are into wood (encapsulated, somewhat)!

EDIT: Actually, I take some of it back: The fuel and ski locker hatches/lids in the new hull -- for sure - NO WOOD, I just remembered it from doing sound proofing. THAT IS DIFFERENT FROM THE 2012 (190) which had wood in the hatches/lids.

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[CrankyGypsy]

somehow, i've been fortunate not to encounter the stringers in my 2005 AR230. on the hull, i found a layer of grey "compound" (at least 1/16" thick) between the inner/outer layers of glass (outer layer of glass at least 1/8" thick) - i assumed this is there to promote a full cure in the mold before it is pulled and "beefed-up" with stringers. though i would also assume they use vacuum bagging, which would seal the air out - so maybe this layer is placed there to be abraded later for the inner glass bond?

sorry (not sorry), my repair never required me to grind far enough beyond the grey layer to uncover anything more revealing of the hull construction. i can tell you there is 0.50" balsa (not ply) in the floor of the 2005 models. i am in the middle of a floor repair and will poke around a bit. if i turn anything up, i'll post it.

i had to do a repair at the very bottom of the baffle (divider) between the engine bay and the fuel tank - this was 3/16" FRP with no core. however, i would have to guess that further up, SOMETHING additional has to be there to add strength across this span. also, the fuel tank is cubed, so it obviously has to sit on something flat - that could be some sort of integrated stringer? you could carefully try drilling a shallow hole into the baffle between the ski locker and the fuel tank (an easily concealable test/repair) to get a "core sample."

maybe someone who has installed an additional bilge pump and drilled the hull for new pee holes (or remove your pee fixtures to look) can provide insight to the thickness of the glass layers in that part of the hull.

 

[jcyamaharider]

Here are some pictures of different parts of the hull that I have drilled for thru hull fittings for thickness reference. I also drilled thru the back wall of the engine compartment and this was also thicker then I thought, maybe a good 1" thick but mostly wood if memory serves me.

 

[swatski]

Yep, @jcyamaharider's looks the same as the new hulls, and a 2012. Skinny as a rail.
I'll look for some pics from my installs.


The new lids are some light weight compound, not sure what it is, but it is not FRP. Maybe SMC?

Yeah, our boats are built just like Corvettes, but with a purpose .

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