Restoring 1975 glasply 2300, bilge question...

SeanF45

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Dec 18, 2024
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3
Ok, so I picked up a 1975 glasply 2300 to fix up... thing was rough, and as I tore into it, even rougher... i could just scrap it, but I like a project, so im gonna just overhaul it as a long term project.

I pulled up the deck a started chasing rot. And all the stringers are rotted all the way up. Ill be replacing them with laminated honeycomb panels.

My questions come to the design of the bilge, though... since i am redoing it all, i can make adjustments, and I was confused by how it was set up... at the entrance to the cuddy, you step down from the main deck heigh to a lower floor. Ahead of the small square recess is the head. There is a drain hole in the floor.
One of the main sources of rot in this boat was from leaking window seals, which were leaking into the cuddy. As I chased the rot, I cut out the floor there and was surprised that there was no drain hole in the bilge from this front second back to the rear of the boat. Of course the wood had rotted at the crossmemeber, but there was enough fiberglass on the port side that water was still sitting there, while the starboard side had drained through the rotted wood.... so what is the point in putting a drain into the flood to a space that could never evacuate the water? Did they just forget to install the drains in the crossmemeber? Or is there some reason that I am not comprehending, to keep this areas separate from the rear second of the bilge?

Anyway, my plan is to basically build with the supports in the same places, but to add drainage, like the rear crossmember has.

there a more elegant solution?

20260916_014428(1).jpg20260916_014439(1).jpglv_0_20260916045756.jpg
 

MikeSchinlaub

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Jan 14, 2025
Messages
952
Yeah, that was dumb. It's a boat, water WILL find a way to get in every bit of it. Add drainage. It would also be great, but probably impractical, to have access to every drain hole so you can clear any debris build up.
 

bakerjw

Petty Officer 1st Class
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Apr 3, 2013
Messages
377
Ah, I love people willing to take up a challenge and be advised that it will be enjoyable. Itchy and sticky but in the end very rewarding. The people here helped me through the WTH stages early on in my rebuild 13 years ago.

From what I have read, Nidacore is not an ideal material for stringers. It is great for decks and sides of consoles and such but not for the forces that will be encountered as stringers and bulkheads.

If you are very very thorough with your glasswork, regular exterior CDX plywood works well for stringers and bulkheads. I redid my Stratos 13 years ago and all of the stringers and bulkheads are dry and solid as the day they were glassed in place.. You can spend extra on marine plywood but as I've read it uses the same adhesives as CDX but has no voids. You can use also go with Coosa which is lighter but is much more expensive and sometimes hard to source.

For the transom, it is Coosa all the way. IMHO.

I have no affiliation, but I sourced my Coosa and Nidacore from Merritt supply and shipping the 4x8 sheets was only $250.00. I also added on a bunch of 1708 and 6 gallons of epoxy.

I am not a complete expert but have been down the road and learned what to not do. Yesterday was one of those lessons.

Is that an IO model?
 

MikeSchinlaub

Ensign
Joined
Jan 14, 2025
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952
In my opinion, plywood is best. Coosa is alright because it won't rot, but given its strength without glass, I wouldn't consider it (or nidacore) as structural materials. Meaning, if you use them, don't factor them into the strength of your structure. Consider them void fillers, and build the glass up as if it is the only thing providing structure, because it is.
 

redneck joe

Supreme Mariner
Joined
Mar 18, 2009
Messages
16,150
In my opinion, plywood is best. Coosa is alright because it won't rot, but given its strength without glass, I wouldn't consider it (or nidacore) as structural materials. Meaning, if you use them, don't factor them into the strength of your structure. Consider them void fillers, and build the glass up as if it is the only thing providing structure, because it is.
on an i/o would coosa be ok? Not a lot of force from engine, just swim platform and tow ropes?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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53,135
the boat was designed to last 15 years and be replaced.

it did that and then some.
 

MikeSchinlaub

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Jan 14, 2025
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952
on an i/o would coosa be ok? Not a lot of force from engine, just swim platform and tow ropes?
I'm not saying that it can't be used, just that it isn't providing the majority of the strength. If you remember, the first thing in my work thread was a big cobalt with a coosa transom.

So just more glass, and a bigger overlap area. Maybe instead of 2 mat and 1 roving, double it. 2 mat, roving, 2 mat, roving. Stagger any seams.
 
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