Water tank treatment

[jaywalker]

After reading of some water tank horror stories I deciced to clean my boats integral tank (it is 20 years old, I have had it for 1 year).

Good news, when I lifted the lid it looks as though it was blacked recently. I emptied it, dried it and put on another coat of potable blacking.

Do I need to add anything to the water when refilling or is it ok to use straight away?

[bowten]

After reading of some water tank horror stories I deciced to clean my boats integral tank (it is 20 years old, I have had it for 1 year).

Good news, when I lifted the lid it looks as though it was blacked recently. I emptied it, dried it and put on another coat of potable blacking.

Do I need to add anything to the water when refilling or is it ok to use straight away?

Should be ok,but you could add little Milton sterilising fluid.

[jaywalker]

Thanks for that, it is what I was hoping.

I have one other problem. My water tank is below the well deck in the cratch. When I fill it completely, the front end goes down and the self draining holes end up at more or less at the water level. When the boat is moving the water comes into the well deck, also if we sit up front.

The ballast is concrete slabs under the floor, would a couple of 56lb weights under the deck at the blunt end make any difference at all? It seems to be an enormous tank, is it just a case of making sure I dont fill the tank? Is this a common problem?

Thanks in advance for any help. JIM

[Rebotco]

Thanks for that, it is what I was hoping.

I have one other problem. My water tank is below the well deck in the cratch. When I fill it completely, the front end goes down and the self draining holes end up at more or less at the water level. When the boat is moving the water comes into the well deck, also if we sit up front.

The ballast is concrete slabs under the floor, would a couple of 56lb weights under the deck at the blunt end make any difference at all? It seems to be an enormous tank, is it just a case of making sure I dont fill the tank? Is this a common problem?

Thanks in advance for any help. JIM

 

I'm no expert, but even as a novice, that sounds like a disaster waiting to happen.

I believe there should be NO direct openings in the hull lower than 10" above the waterline.

This really sounds dangerous - I would refuse to go on that vessel as it is described. On a river it could be life threatening, or even going up a lock.

I shudder to think how easily that could sink.

Hope some more knowledgeable people come and advise you.

Can you remove ballast from the front?

[Albion]

I'm no expert, but even as a novice, that sounds like a disaster waiting to happen.

I believe there should be NO direct openings in the hull lower than 10" above the waterline.

This really sounds dangerous - I would refuse to go on that vessel as it is described. On a river it could be life threatening, or even going up a lock.

I shudder to think how easily that could sink.

Hope some more knowledgeable people come and advise you.

Can you remove ballast from the front?

As I understand it there has to be 10" between the water line and the point of entry into the boat interior. So, in this case, the scupper holes can be low as long as the front door cill or any air vents sit at 10" above the waterline.

Roger

[Ex- Member]

Thanks for that, it is what I was hoping.

I have one other problem. My water tank is below the well deck in the cratch. When I fill it completely, the front end goes down and the self draining holes end up at more or less at the water level. When the boat is moving the water comes into the well deck, also if we sit up front.

The ballast is concrete slabs under the floor, would a couple of 56lb weights under the deck at the blunt end make any difference at all? It seems to be an enormous tank, is it just a case of making sure I dont fill the tank? Is this a common problem?

Thanks in advance for any help. JIM

 

Doesn't sound great to me either. I would remove some front ballast, however this might effect the boat when tank is nearing empty. You need to find a happy medium though, adding ballast to the stern I don't think will help, you're clearly too heave at the front with a full tank of water and it shouldn't be like that. Remember the front of the boat should be higher than the rear especially when the water level is low. It's possible someone had a very big tank fitted and it's too big.

 

I've just measured our drain holes from what was the water line when we were last in the water and their 8.5 inches, there's also a 3 inch riser to the cratch doors step and that's level with the bottom of the front vents so 11.5 inches in total. We are wide beam though and a full tank of water 170 gallons I recall doesn't make much difference, on a nb though it will.

 

ETA Sorry water tank is 80 gallons not 170

 

 

 

Edited May 21, 2012 by Julynian

[Bones]

Thanks for that, it is what I was hoping.

I have one other problem. My water tank is below the well deck in the cratch. When I fill it completely, the front end goes down and the self draining holes end up at more or less at the water level. When the boat is moving the water comes into the well deck, also if we sit up front.

The ballast is concrete slabs under the floor, would a couple of 56lb weights under the deck at the blunt end make any difference at all? It seems to be an enormous tank, is it just a case of making sure I dont fill the tank? Is this a common problem?

Thanks in advance for any help. JIM

 

They are rather low, but my drain holes are also rather low. I removed quite a bit of ballast from under the front deck which seems to have done the trick and although they are now barely two inches above the water line the deck remains dry unless there are people sitting at the front and we are cruising on rivers (or on a narrow canal, which is often, whereupon water sloshes in, and then out).

 

I think the 10cm rule applies to hire boats, but is advisable on private craft. As long as sink outlets are SEALED up to 10cm above the water line they are fine, and it is recommended that there is a higher step on the door or something if the drain holes are too low (although by definition they are going to be low I would have thought)

 

My front deck floor never actually fills entirely with water.

Edited May 21, 2012 by Bones

[Ex- Member]

They are rather low, but my drain holes are also rather low. I removed quite a bit of ballast from under the front deck which seems to have done the trick and although they are now barely two inches above the water line the deck remains dry unless there are people sitting at the front and we are cruising on rivers (or on a narrow canal, which is often, whereupon water sloshes in, and then out).

 

I think the 10cm rule applies to hire boats, but is advisable on private craft. As long as sink outlets are SEALED up to 10cm above the water line they are fine, and it is recommended that there is a higher step on the door or something if the drain holes are too low (although by definition they are going to be low I would have thought)

 

My front deck floor never actually fills entirely with water.

 

Hi Bones, the guidance is 10 inches or 25cm or 250mm for the well deck drain holes I believe. 10cm is 4 inches and might be ok for sink outlets but not well decks, not sure on that one.

 

 

 

[Québec]

That i.e. drain holes at water level, happened to us once. Major panic, as you can imagine, with water seeping onto the deck. Primary cause overfilling the integral water tank which also takes up the whole area beneath the well deck and the hull. Exacerbated by very little fuel in the rear tank. A re-distribution of the ballast with the both tanks half full has markedly improved the trim. No more panic....until the next one.

[Bones]

The boat safety scheme is downloadable here

http://www.boatsafet...Contentsweb.pdf

I am still pretty sure that requirement is for hire boats (not least because I have a valid boat safety certificate)

 

and in here, for hire boats

http://www.boatsafet...e%20Pt%2010.pdf

 

it says

To reduce the risk of your boat sinking if it keels over or is excessively weighed

down, it's a good idea for privately owned boats to only have openings which

are at a height of at least 250mm (10ins) above the waterline.

Where openings are necessary below this level this risk can be reduced by

ensuring that these openings are permanently and securely connected to ducts

or pipes, which are watertight up to that level.

Self-draining cockpits may not be able to meet the 250mm (10ins)

recommendation but, for privately owned boats, it's a good idea to stop water

getting into other parts of the hull by incorporating non-return valves in the

drains and/or having bulkheads or cills up to a height of 150mm (6ins).

 

Either way, regardless of what the book says, safety is important. My drain holes are rather low but quite a bit of water has to come in to the well deck (my well deck is larger than most) for it to get to door level. I wish mine WERE 4 inches!

Edited May 21, 2012 by Bones

[owen]

After reading of some water tank horror stories I deciced to clean my boats integral tank (it is 20 years old, I have had it for 1 year).

Good news, when I lifted the lid it looks as though it was blacked recently. I emptied it, dried it and put on another coat of potable blacking.

Do I need to add anything to the water when refilling or is it ok to use straight away?

i think also some people use a small amount of bleach to a tank of water i dont know the amount but im sure someone will know on here i think that is what you were asking

[dor]

Good news, when I lifted the lid it looks as though it was blacked recently. I emptied it, dried it and put on another coat of potable blacking.

Do I need to add anything to the water when refilling or is it ok to use straight away?

 

You might find you need to rinse out the tank a couple of times to get rid of any taint. It helps if it is left to dry longer before refilling.

 

I don't think people need to be too precious about the state of their water tank. I've been drinking from mine for years without harm, and the inside of the tank on my last boat looked like a brown coral reef. I do have a ceramic filter on the cold tap in the galley though. It's more important ot keep your hosepipe clean when refilling - not dropping the end on the ground or in the canal and flushing through to remove any water left in the pipe from previous filling.

 

ETA: If you do want to sterilise it, use a little cheap thin bleach. The 'thin' bit is important - it is basic hypochlorite which will release a bit of chlorine which will dissipate. Thick bleach has other things in it which you do not want in your water tank.

Edited May 22, 2012 by dor