Hunter 26 Cabin Floor/Ballast Tank

[jao1972]

I have a 1994 Hunter 26 water ballast. Does anyone know for sure if the cabin floor is or is not the top of the water ballast tank? This is the recessed area for the wood insert in the floor. See the attached picture.

I am replacing the wood insert in the cabin floor. Mine was screwed down around the edges. It also was glued. More than half of the screw holes went all the way through the 1/4" (about) fiberglass floor. I was able to insert a smaller drill bit in these holes and could feel another hard layer about 3/4" below.

My sense is the second hard layer I am feeling is the top of the ballast tank. You can see inside the access door for the tank valve that it looks like the top of the tank slopes down all around where it meets fiberglass that forms this compartment. This makes me think there are two layers here.

 

[jssailem]

I’m not an expert on the Hunter 26. @Crazy Dave Condon is. He might be following and can provide specific info.
I have a copy (here is the link Water Ballast for Trailer-Sailers ) of this Good old Boat article.
Good structure information.

 

[Davenport]

I don't know much. Can you look and feel the ground under the sink and feel sideways toward the cabin to feel if there is much added between water ballast and the current floor level. - D

 

[Davenport]

Hunter H26 Sailboat Interior Update

Adventure Werner

This video on YouTube maybe maybe shows ballast tank is right under the rear floor area.

 

[jao1972]

Thank you for responding and providing the pictures. I think the picture of the ballast tank top installation makes the most sense. The part of the raised area where the tank vent is located is curved down. you can see this curvature when looking inside the wooden access door/step. It makes sense that a second floor layer was added. Again, my floor insert was screwed down. 2/3 of the holes when all the way through fiberglass. I could feel a hard layer below about 1/2" to 3/4" down. This aligns with the picture of the access hole.

 

[Davenport]

If there is anything above the ballast tank it definitely has no strength, you can feel my h260 floor bend and bounce if I step too hard. . . . . Please share any photos of the floor area and underneath that, that you may have. Happy boating.

 

[jao1972]

Mine too. I pondered not replacing the wood insert, but it needs the structure. Boatyard recommended drilling 1/4" holes and putting spray foam between the layers. I would be concerned then about loading the top of the tank. Will do. I will get some pics this weekend.

 

[jao1972]

ChatGPT provided the following. The information comes with all appropriate cautions, but tracks with what I am seeing. I am not an AI expert, so take it for what it is.

Key construction details

• The tank is formed primarily by the hull itself as the bottom and sides.

• A one-piece molded fiberglass ballast tank lid (top) is dropped into place over the hull cavity. It is bonded to the hull with marine putty, and the perimeter seam is tabbed/glass ed with several layers of fiberglass from above. The underside of the lid is typically gel-coated.

• A separate one-piece fiberglass floor pan (cabin sole structure) sits above the tank lid. There is mostly a small air gap between the top of the tank lid and the underside of the floor pan. Marine putty is applied in selected spots between them to reduce flexing/sloshing of the lid when the tank is full.

• The visible cabin floor (often a teak-and-holly sole or similar) sits in a recessed area of the floor pan and is glued/sealed in place.

• Access to the fill/drain valve and vent is under the bottom companionway step (or nearby molded step). The vent is kept high so the tank fills completely; the bottom hull valve is closed tightly once full. The tank top is often slightly sloped to help air escape to the vent.

When empty (for trailering), the boat draws about 1’9”. When full, draft is about 6’ with the centerboard down. The floor can flex noticeably when the tank is empty; it firms up once full and sealed.