Adding bigger water and fuel tanks?

[mrk123]

Is adding larger water and fuel tanks straightforward or do most boats say the 1980s not like it?
Seen a few boats but only have 100l water for example!
Is it easy enough to add larger water and fuel tanks where the originals are?

[flee27]

That is a hard question to answer. In general water would be a lot easier then fuel. You didn't mention what size boats your looking at. But space is going to be one issue. Can ignore the weight either. But that might not be such an issue depending on boat size/design. Generally speaking I would say space and plumbing are going to be the biggest obstacles.

With better boat specifics I am sure you will get some more relevant answers.

Foster

[ItDepends]

An impossible question to answer in a generic way. It would be extremely unusual that you could remove a 100 liter tank and simply drop in a 200 liter tank. Boats are just not built that way.

If you are boat shopping, you would be wise to limit your shopping to those boats that have only the tankage that you require and NOT plan on changing such a basic parameter.

[argosail]

One solution I was looking at is replacing the head with a composting toilet, then taking out the holding tank and replace with a water tank, could use the thruhull as a saltwater inlet for the sink too to save freshwater.

[bil56]

replacing a soft tank (under the bunk) by a custom hard tank may get additional gallons ...

[mrk123]

Originally Posted by bil56

replacing a soft tank (under the bunk) by a custom hard tank may get additional gallons ...

Hard tank soft tank? Can you explain?

[mrk123]

Originally Posted by ItDepends

An impossible question to answer in a generic way. It would be extremely unusual that you could remove a 100 liter tank and simply drop in a 200 liter tank. Boats are just not built that way.

If you are boat shopping, you would be wise to limit your shopping to those boats that have only the tankage that you require and NOT plan on changing such a basic parameter.

I agree, but want to keep budget on budget if possible.

I want a 35ft but looking more likely to be a 30ft for now, first boat.
But most of the boats I been looking at in this spec have small tanks, 100/150l.

300 would be a nice minimum!]

I guess can always get a water maker? And / or store water in ali tanks on deck or in the cabin.

[Rod Headlee]

Ronco plastics has a huge catalogue of tanks. In our Catalina 38 we just picked one out to fit the space we had. We still only squeezed in 40 gal of water. We had custom stainless steel fuel tank made to fit behind the engine. We carried 60 gal fuel total. We had a 1gal per hour watermaker, We put about 22 thousand ocean miles on like that. We caught a lot of rainwater. It was plenty of fuel for that boat. It all depends on the boat.

[ForeverDes]

Originally Posted by argosail

One solution I was looking at is replacing the head with a composting toilet, then taking out the holding tank and replace with a water tank, could use the thruhull as a saltwater inlet for the sink too to save freshwater.

I'm working on this exact project now. I took out a 9g holding tank when I put in a composter, and I'm getting ready, parts in route, to add a 16g water tank under the v-berth, doubling my on board supply. I'm also planning on using the thru hull to a raw water faucet to save fresh water.
26' boat so 30 gallons is about as good as it can get for me.

[Jammer]

Depends. Often it is easier to add more tanks, rather than replace an existing tank with a larger tank. The tanks can be plumbed together in such a way that they can be filled and used like a single tank.

[goboatingnow]

my 36 footer has 300 L of water , typically 7 days without undue scrimping, no sea water in galley , could be stretched to 10 days at a push

adding boils down to two issues , where is the space and will you compromise the dynamics of the boat, I delivered a 38 footer that had double the diesel tanks installed and she was really arse heavy and sailed badly

[Jammer]

Well you don't have to fill them full every time just because they are there.

[goboatingnow]

Originally Posted by Jammer

Well you don't have to fill them full every time just because they are there.

whats the point of that , firstly you have given up space for something you are now not using, that's rather silly,

secondly if the boats dynamics are compromised when you do use it , you'll be compromised

if you cant justify the extra tanks on an ongoing basis , then its ridiculous tearing the boat apart to add permanent tanks that you'll not use regularly . Use deck cans, etc to provide occasional storage !!

[hjohnson]

So our Ericson 27 originally had a 20? gallon hard tank under the Vee Berth up front. Not a whole lot of water, but if you used the seawater pump (at the time) you could get away with it. She was also upgraded to inboard propulsion back in '83, but since she was originally ballasted as an outboard model, she always sat a little nose-high in the water. Later, we added a 40 gallon bladder up front, which a) gives us a lot more water storage and b) makes her sit nice and flat, as it seems to balance out the engine.

[psk125]

Originally Posted by mrk123

Hard tank soft tank? Can you explain?

For a transatlantic trip our skipper installed a flexible rubber water tank under the forward berths, adding about 15 gallons (60 l) to our supply on a 38' boat. 300 liters is a LOT of water on a 30' boat. The weight of that much water could negatively impact how the boat performs and in some cases could be dangerous.