Haines Hunter Rebuild - Keel Ballast Chambers?

[IronPrice]

Now that the kids are all grown, and moved out, we've sold our alloy powerboat which was suitable for up to six people, and we are downsizing to something suitable for two.

The plan is to find an old V16 or V17 Haines hunter and do a rebuild. The idea is to make a little pocket-battleship hardtop for fishing. There are plenty of similar builds documented for inspiration and ideas.

As part of that, I want to add floodable keel chambers (1). I'd value some advice on whether that is a bad idea in a composite boat - from a materials suitability perspective. Haines Hunter built in ortho-poly resin. It's likely I'll have to use epoxy over that, as I doubt any of the *ester resins will bond to ortho-poly that old.

Obviously, I have vast amounts of detail to work out. But I have a basic design in mind for the chambers that I think will work. I'll also be adding an underfloor fuel tank - about 75L and foam in the underfloor compartments outside of the inner most stringer on each side (I'll be replacing the existing stringers, and keel with a grid, which the deck will sit on).

Thanks in advance.

(1) A sealed chamber either side of the keel, with an opening at the transom. At rest, the chambers flood, lowering the centre of gravity and improving stability. When planning, the chambers empty, so you aren't dragging that excess weight around. Or the transom openings can be sealed to keep water in the keel - if extra ballast is needed for rough conditions. The system works really well in Surtees boats, but they are aluminium.

 

[gonzo]

There are thousands of RIBs with floodable chambers and they are fiberglass.

 

[montero]

How are the filling and pumping-out operations carried out?

 

[HelmutSheina]

This is not without precedent, and I remember some Australian boats being built with floodable bilges where they had an opening in the lower transom that drained once moving. It may have been Haines Signature, but was definitely a mass production fibreglass series.

I cannot see that the material would be an issue once well sealed and I'd feel more comfortable with water laying in a composite hull than aluminium. Depending on the size and shape of the cavity, but baffles might be a major help.

 

[gonzo]

All the RIBs I used had one or two holes in the transom and the water emptied after the boat picked up speed.

 

[montero]

Non-return squeeze hose valves . What are they used for on boats? Can they be used on the exhaust?

 

[IronPrice]

How are the filling and pumping-out operations carried out?

The chambers are open at the transom. At rest the opening is below the waterline, so the chambers naturally flood. When planing they naturally drain. If you want to keep the chambers fill when planing then a flap is closed over the openings in the transom

 

[IronPrice]

This is not without precedent, and I remember some Australian boats being built with floodable bilges where they had an opening in the lower transom that drained once moving. It may have been Haines Signature, but was definitely a mass production fibreglass series.

I cannot see that the material would be an issue once well sealed and I'd feel more comfortable with water laying in a composite hull than aluminium. Depending on the size and shape of the cavity, but baffles might be a major help.

Yes, transverse baffles with limber holes would be part of the structure of the chambers. They would prevent longitudinal sloshing and provide structural strength.

 

[HelmutSheina]

Non-return squeeze hose valves . What are they used for on boats? Can they be used on the exhaust?

Check valves are used extensively in marine equipment such as various pumps, toilets, exhausts, scuppers, filters and air vents. I reckon you could dig up a bunch more without trying very hard.

For exhausts you can fabricate a hinged flap from SS to cover the outlet. Else wise there are plastic and rubber offerings, which you should get a few years from.

But this is a critical system with potentially catastrophic consequences for failure, so don't cheap it out or stick together a backyard special, otherwise glug-glug.

Marine Exhaust Accessories

At last an answer to eliminating the annoying clanking and banging caused by stainless steel anit-burn flappers.

www.cpperformance.com

It you are very good on TIG and general fabrication You could consider building your own SS set. Not trivial, and mass manufactured items are available. I think I searched "marine exhaust flap" and a lot of relevant stuff was returned.

5″ Internal Retro-Fit 4″ Long Tube Stainless Flap Installed | Marine Engine Parts-Boat Parts and Accessories-Stainless Marine Boat Parts Online

www.stainlessmarine.com

Mercruiser have internal ones to help with backwash on the through prop exhaust and an external rubber flap on any through transom ones I've seen, which is not many more than a handful.

Amazon.com

 

[skaraborgcraft]

Avon "searider" RIBS from decades ago. Hole in the bow and stern. Filled when stationary and emptied once moving.

 

[montero]

Yes. I’m referring to this type of drain valve:
There is a hole and flange on the outside of the transom, and a hose is fitted over it—the one that is compressed by water pressure. What is that called?
Sock valve ?

 

[montero]

Duckbill ...

 

[rnlock]

I've read horror stories about fuel attacking integral composite fuel tanks in homebuilt airplanes. It's probably a good idea to really do your homework. I don't know about other fuels, but in the USA automotive fuels vary in composition, especially from summer to winter. They usually include alcohol. I wonder if fuel bladders could avoid the problem. It might be a good idea to use static dissipative materials if you make your own tanks, and pay attention to other possible static issues.

 

[HelmutSheina]

Avon "searider" RIBS from decades ago. Hole in the bow and stern. Filled when stationary and emptied once moving.

I remember those, it is probably where I first encountered water ballasting on an outboard bost.

 

[IronPrice]

I've read horror stories about fuel attacking integral composite fuel tanks in homebuilt airplanes. It's probably a good idea to really do your homework. I don't know about other fuels, but in the USA automotive fuels vary in composition, especially from summer to winter. They usually include alcohol. I wonder if fuel bladders could avoid the problem. It might be a good idea to use static dissipative materials if you make your own tanks, and pay attention to other possible static issues.

These are ballast tanks. For seawater. No fuel.