Bottomless Bilge?

[Steviecracknell]

I was thinking of reducing the depth of the bilge in my Arden 4 sailing yacht. The size is around 600mm deep x 500 x 200, I was going to reduce the depth to 300, fill the void with expanding foam, then cap this with plywood and glass to a finish. Would I be better off filling the void with more ballast, ie lead, the same used to fill the encapsulated hull, or would the expanding foam be suitable. The reason for this is purely cosmetic, and ease of maintaining. I'm not sure if there would be a down side to this modification, (wondering why the depth was so deep!!)

Cheers Stevie.

 

[William_H]

Filling bilge

The choice is yours regarding bilge fill. Do you want more stability and particularly righting power at knock down angles? In which case fill it with lead. Or do you want to minimise weight to maximise performance in which case fill it with foam which will also provide some buoyancy. Although deep is not the best place for buoyancy as weight of water above in a swamping situation will make the boat less stable.
Or you could fit a water tank in the space then a water tight cover or even surrounded by foam so you can havee it empty for buoyancy or full for ballast. good luck olewill

 

[prv]

Deep bilge is good as far as I'm concerned. Makes the water more likely to stay out of stuff I care about!

Probably not worth trying to increase ballast unless you know you have a problem at the moment. If you add enough to make a difference (and if not, why bother?) then you have to worry about the additional stability adversely affecting the motion and also, in theory at least, increasing the loads on the rig (because the boat won't lean over and spill wind so easily). Although on a 24-footer, the effect is probably no more than someone standing on the side deck which is obviously ok, hence why I say "in theory".

I believe builders' spandy-foam soaks up water, which may not be ideal although you are planning to encapsulate it. You can get two-pack foam which doesn't absorb water.

Not really sure what the goal is, to be honest. Only downside I have with my deep bilge (about 4 feet below the cockpit sole) is dropping things into it. I keep a park-keeper's litter-picker on board which solves that one, but your two feet is within arm's reach anyway.

Pete

 

[sighmoon]

Why not just put a bit of ply over it? You might want the stowage one day.

 

[Graham_Wright]

Put a tank in it;- water or fuel. You then can tune the ballast v buoyancy to suit the occasion!

 

[Bosun Higgs]

Bottomless bilge? Is this thread about The Lounge?

 

[LittleSister]

Only downside I have with my deep bilge (about 4 feet below the cockpit sole) is dropping things into it.

Me too, especially the deepest and hardest to reach bit behind our engine. I've long intended to fix some fine plastic mesh across the opening, fixed to the hull with some velcro or similar.

When I had a shallower, more easily accessible bilge on another boat (where our water tanks are on current boat), I found it an ideal place to store potatoes and other things I wanted kept cool (you remember summers, don't you?), together with anything heavy such as the kedge and its chain, spare food and drink tins, etc.

 

[Billjratt]

Maybe there was some method in the madness of the designers who put the deep cesspits-sorry bilges in our 'traditional' style boats.
If you have a serious invasion of liquid, it will take some time before hitting the floorboards,so, if you have a bilge alarm (or a beeper wired to the auto pump) you will be dealing with the problem long before much damage has occured.
The ongoing problem is housekeeping - deep bilges usually go with dripping propshafts
and debris dropped or lost, so as metioned above, a long-reach grabber of some sort is required, along with (in our case) a sponge on a stick, in order to keep the house reasonably clean.
Once the system is managed, it is the best.
A shallow bilge will have smelly water sloshing about in places you would not believe, drying out and then festering, leaving smells that are surprisingly difficult to get rid of.

 

[vyv_cox]

As already mentioned, don't use expanding foam unless you can get hold of professional closed cell polyurethane, which is expensive to buy and apply. The types readily available for DIY, such as aerosol builders foam and two-pack ones sold by the likes of Glasplies are only partly closed cell and will absorb water if immersed. I have dug such foams out of canoes after a year or two when their buoyancy function had completely vanished. The foam was totally saturated.

 

[Poignard]

Could be problems when you come to sell the boat. Suspicious buyers might wonder what it's hiding.

Might be regarded as a modern equivalent of the old practice of pouring cement into the bilges of an old wooden boat to hold rotten frames, floors, garboards together.

 

[kds]

That design has a good reputation for sailing and sea-keeping. Don't add any more ballast.
I find a deep bilge very useful. Store things in it in plastic boxes and 2/3 of it is water tank.
Ken

 

[Avocet]

Mine's the same. If you drop something in there. you're stuffed! Unfortunately, I can't cap it off because I need to get access to the bolts that hold the bronze shoe for the bottom rudder pivot to the fibreglass.

The two other big problems with it are the noise from under the engine that reverberates round in that space, and the length of time it takes to drag water up from there with the bilge pump. The hand pump operator has to work quite hard to lift the water about 4 feet!

However, as other have said, there are great storage advantages. In the end, I just went for a simply plywood infill panel, covered in sound deadening. It's only a few screws to remove it, but if I drop anything when servicing the engine, at least I can reach them!

 

[Poignard]

Or you could fit a water tank in the space then a water tight cover . . .

A good idea - my Twister has a 36 gallon water tank in the keel and a well for the bilge pump strainers. The water tank has a removable lid, bolted in place with a rubber gasket under.

 

[prv]

Me too, especially the deepest and hardest to reach bit behind our engine. I've long intended to fix some fine plastic mesh across the opening, fixed to the hull with some velcro or similar.

Yep, a mesh cover was on my very first jobs list when we bought the boat, still not got round to it . The grabber was among the tat in my shed anyway, so I just bunged it in a locker and have occasionally needed to use it. Probably never will get round to the cover.

On the Cherbourg trip I was able to help out my pontoon neighbour who had dropped a handle-less plastic bucket over the side, and couldn't reach it from their high freeboard. They were a bit surprised to be offered a grabber when their boathook clearly wasn't working, but it did the job

Pete

 

[Scotty_Tradewind]

I'd leave the space and try to keep it fairly clean. It could be invaluable to you or for a potential buyer to see one day as others have said.

The one big asset should be having an automatic bilge pump and the hose for the manual pump in there. Better to have that volume to collect any influx of water in an emergency just to buy you a little time.

 

[Steviecracknell]

Don't fix, if it aint broke!!

Thanks for the varied responses. I'm still undecided, but swaying towards leaving it as intended, a design that was devised by boaties cleverer than I.
A good clean up and paint, then place an auto pump below a false panel that can be removed, purely for cosmetic value, as the engine will be restored and painted.
Cheers again Stevie.

 

[rotrax]

Bottomless bilge? Is this thread about The Lounge?

Nice One!