Water tank painting

[stuart]

Hi everyone. New shell and new empty steel water tank.

 

Whats the best way to paint it, do we need to use a primer and undercoat or just slap on the water-tank-black?

 

How about washing the tank out/checking for leaks? etc?

[NB Willawaw]

Stuart,

 

I wll leave other more qualified brethren to respond to your question, but a word of warning from experience. Do it properly and take the time to get it right !

 

Near me is a wide beam 58 footer, which is less than a year old.

The bow locker doubles as a water tank and the special black coating is already coming off in places and light rust starting to appear on the inside of the tank.

 

It occurred to me that this will be a pain to rectify as you have to access the tank through a small inspection hatch and remove the coating, strip back to metal, prime and then try to re-coat.

 

I've suggested the owner take it up with the yard, but its worth taking some care on this aspect if you are doing it yourself.

[John Orentas]

Just paint it with a couple of coats of bitumastic paint directly onto the steel (make sure it says it suitable for water tanks on the tin), but make sure it is dry first, not easy at this time of year. A fan heater will help drying out.

 

I suspect the example was not dried out.

[NB Willawaw]

Stuart,

 

Although not directly related to the water tank issue, you may be interested to view the following website which covered another Liverpool boat called Isabella:

 

http://www.nb.isabella.btinternet.co.uk/

[Alan Saunders]

Just paint it with a couple of coats of bitumastic paint directly onto the steel (make sure it says it suitable for water tanks on the tin), but make sure it is dry first, not easy at this time of year.  A fan heater will help drying out.

 

I suspect the example was not dried out.

<{POST_SNAPBACK}>

I have found a bitumastic paint that claims to be suitable for potable water tanks, the manufacturer's instructions are as follows:

 

1/ Remove corroson, oil, moisture etc.

2/ Apply one coat and allow to dry for 24 hours with ventilation!

3/ Apply second coat and allow to dry for 24 hours with ventilation!

4/ Apply third coat and allow to dry for 72 hours with ventilation!

5/ Fill with water & allow to stand for four days.

6/ Empty & refill twice.

7/ If water is still tainted, repeat from item five.

 

There must be a better way!

 

Alan

[Richard Bustens]

Yep. you should have got a s/steel one in the first place.

[howardang]

Yep. you should have got a s/steel one in the first place.

<{POST_SNAPBACK}>

[howardang]

<{POST_SNAPBACK}>

A few years ago there was a product called Floatcote which was used to paint the inside of ships ballast tanks - I don't know if it is still manufactured. The idea was that you added the correct amount according to the tank capacity and it floated on the surface of the ballast water. As the tank emptied it coated every square inch of the tank surface. If you left it for a few hours before refilling the tank the residue dried and you were left with a perfectly coated tank. I seem to remember that there was a version which was suitable for potable water tanks.

 

The other traditional methd, of course, was to cement wash the pot water tanks each year using a watery mix of water and cement. That needed application with a distemper brush after removing any loose flakes from previous applications, but was standard practice on merchant ships until fairly recently.

 

Regards

 

Howard Anguish

[John Orentas]

Where has all this nonsense come from, every day all of us drink water that has been stored in tanks and pipes that have been treated with Bitumastic paint, how many of you can see a steel, iron or concrete water tower from where you are sitting now.

 

A properly painted water tank is a perfectly good method of storing water which has stood the test of time.

 

Of course the paint manufacturers cover their backs, that is the age we live in.

[Guest st170dw]

I have a lead mains water pipe feeding my house - I suspect that is probably a greater risk to me than an enclosed water tank. The sort of tank that would have probably been painted with lead oxide in Victorian times.

 

Or am I unaware of the thousands of people poisoned by the lack of a coat of paint?

[Chrissie]

Lead mains water pipes are considered to be a risk, especially to children. My father would insist that we should run the cold water for several minutes before using the cold water in the morning and never drink from the hot water tap (try googling it for more info).

 

Point is, you may not be aware of other low-level contamination in your potable water tank, so you should ensure that it is properly painted and maintained. Horrible job though.

[ChrisPy]

another use for rust converter (tannic acid based products like Trustan, Vactan)?

 

wait for the tank to go nicely rusty.

apply 2 coats rust converter (preferably in a damp atmosphere!!)

apply the water tank bitumastic (make sure you cover all the surface to avoid direct contact with the rust converter).

I don't think you should need to paint again for the life of the boat.

 

no, I have no interests in promoting this type of product, it is just that I find it so user friendly for people who find it difficult to achieve perfect conditions for painting (all of us?).

[David Schweizer]

Where has all this nonsense come from, every day all of us drink water that has been stored in tanks and pipes that have been treated with Bitumastic paint, how many of you can see a steel, iron or concrete water tower from where you are sitting now.

 

A properly painted water tank is a perfectly good method of storing water which has stood the test of time. 

 

Of course the paint manufacturers cover their backs, that is the age we live in.

<{POST_SNAPBACK}>

 

You are quite correct John, but the bitumin paint has to comply with the BS standards of suitability for drining water. There are several catagories within the regulations and whilst I cannot remember all of them, I recall that the standard for Public water supply is far higher than for private domestic use. The one I used for my tank was called Bituros and was suitable for private use.

 

Back to the original question, I did the job a couple of years ago on my boat, It was probobly the worst job I have ever had to do. My tank is only about 15" high so the whole job had to be done lying down. I found it necessary to completely cover myself with protective clothing and also used a good quality mask as the fumes are quite overpowering. The Bituros is of a much thinner consistency than normal bitumin so it flows very easily, and that includes drips, on the plus side it dries quite quickly and a second coat can be applies after 24 hours. Try and do the job during a cool dry (but not cold) spell in the weather, it can get very warm inside the tank whilst you are working, I also found it necessary to take a break every 15 muinutes or so to get some fresh air and to cool off. After you have done the job it is recomended that you air the tank for 14 days and then flush it out three times before using the tank to store drinking water

[NB Willawaw]

Stuart,

 

I wll leave other more qualified brethren to respond to your question, but a word of warning from experience. Do it properly and take the time to get it right !

 

Near me is a wide beam 58 footer, which is less than a year old.

The bow locker doubles as a water tank and the special black coating is already coming off in places and light rust starting to appear on the inside of the tank.

 

It occurred to me that this will be a pain to rectify as you have to access the tank through a small inspection hatch and remove the coating, strip back to metal, prime and then try to re-coat.

 

I've suggested the owner take it up with the yard, but its worth taking some care on this aspect if you are doing it yourself.

<{POST_SNAPBACK}>

 

On the boat in question, I looked in the documentation to see what coating had been used. It was a special bitumen based coating for water tanks, but when I searched on the Internet, the company appeared to have gone into liquidation.

I did a search looking for alternatives and came up blank.

Can anybody give me a website for a manufacturer (I know chandlers sell the stuff but I like to do my homework first), especially as that boat often takes groups of school children out on trips.

[Echo_Wink]

I seem to have a different tack on this to everyone else so I hope I have done it right ! My boat arrived May last year and painting the water tank was one of the first jobs I tackled. I am now drinking the water from the tank and it seems fine and tastes OK. (ie I am alive and well) On the advice of Liverpool boats, the builders, I painted the water tank interior with a cement slurry (2 coats). That is cement and water and half a pint of white pva glue. Also when I was in the building trade this is what we used to line out water storage tanks (enourmous several house sized ones, like reservoirs on stilts) This gave me the advantage of being able to get in the tank to do the job, because there are no nasty fumes. Be careful of the fumes if you use any kind of paint. I did the inside of the battery boxes with a Hammerite rust inhibititing / eating paint, and even though I did it very carefully trying to breathe outside it made me very ill for a day or two (severe headache and vomiting). I have checked the inside of the tank quite recently, and all is well eight months later, so hopefully it will be ok. This might be easier and cheaper than a bituminous solution, although others may have comments. Hope this helps...

[Clive A]

Hi all,

just finished preparing my water tank, and was suggested rather than using bitumen, my friend, a boat painter of many years, swears by using rubber paint!

The paint he uses is made by Trimite - A48 Chlorinated Rubber Paint.Trimte product information

Has anyone else heard of this being used?

p.s It has a scary flash point - in the range of 21C to 32C !!

All advice greatly welcomed before I consider this approach