Integrated tank need advice

[Tatguy]

Ok I've been working on my boat I have an integrated tank I found the water was rusty so I really cleaned it wire brushes and painted with a bitumen like tank paint Then i let it dry and sealed the hatch 

I've since steralise it 3 times and changed water another 2 times 

 

But here is my question I can still smell bitumen in my water ??

Is this normal? 

 

Thanks in advance 

Tat

[Iain_S]

When we had a share in Copperkins, it usually took 3 or 4 fills to get rid of a slight bitumen taste. In the latter years, I was usually on the boat doing a bit of winter maintenance after the tank had been painted. Usually left or at least a week before filling. I found the quickest way to get rid of the small/taste was fill the tank, leave for a day or so, and then completely drain the water before re-filling. In the meantime, drinking water came from a separate container.

Similarly, when the water system on a trip boat I skipper gets its annual sterilisation, it takes a couple of fills before the water is chlorine free.

It was a potable tank paint you used, wasn't it? 

 

[Lily Rose]

Maybe it depends on the paint you use.

I did mine in June, 3 coats of Black Jack on consecutive days then left it a week before giving it a bit of spraying from the hosepipe (amounting to 25% of a tank full at most) before completely emptying and refilling it. Did not do a complete fill and discard though.

Even at that stage I couldn't detect any smell or taint.

We use it for the kettle, for cooking, for brushing teeth, for rinsing fruit and salad but not for fresh drinking water which we keep in separate containers.

[Tatguy]

Yrs it was defiantly tank paint got it from the local marina did a coat waited 2 days did another then 2 days later did the final coat then left dry for 2 days closed and filled 

Since then I have steralise and changed the water 3 times and changed the water 2 more times in between 

Again the smell is still there 

 

[Ex Brummie]

What did you use to seal the lid?

cYou may be getting contamination from a silicone sealer if this has not properly set. See the recent threads on Maintenance forum.

[Iain_S]

14 hours ago, Tatguy said:

(snip) 

Since then I have steralise and changed the water 3 times and changed the water 2 more times in between 

Again the smell is still there 

I'd forget the sterilising. Chlorine is fairly persistent, and the stuff in sterilising kits for neutralising the chlorine tastes 'orrible!  

[blackrose]

On 30/08/2017 at 09:35, Ex Brummie said:

What did you use to seal the lid?

cYou may be getting contamination from a silicone sealer if this has not properly set. See the recent threads on Maintenance forum.

I very much doubt that a little bit of silicone sealant at the top (which is only ever actually immersed in the water when the tank is completely full) would taint the entire tank of water. If you can smell bitumen in the water then the taint is likely to be from bitumen paint. If the taint persists then personally I would drain the tank, remove the lid and let it dry out over several warm days. Perhaps the paint just needs to cure properly.

By the way, for the OP's benefit you have an integral tank, not an integrated tank.

Edited August 31, 2017 by blackrose

[frangar]

I'd say 2 days is a bit quick to be filling a tank if the top is open and the weather good....if you bolted the top down then left it 2 days that's definitely not long enough. I leave mine at least 7 days with the lid off in good weather and it still takes a couple of full fills to remove any taint. 

[matty40s]

We let it dry and then fill and empty about 4 or 5 times, with the lid still off.

You have trapped vapour above the water by sealing it before filling it, which will probably taint it for a long time unless you take the lid off for a few fills and empties.

 

[Lily Rose]

I went home and left mine to dry for about a week after applying the final coat.

I closed the lid but with a piece of wood inserted to raise it up an inch or so in order to allow it to ventilate but prevent any rainwater getting in and potentially stopping the bottom from drying properly.

When I got back to the boat and checked it there was very little smell left and it was perfectly dry.

Because it takes so long to empty such a large tank I I didn't completely fill it before discarding. What I did do was put in about a quarter of a tank but used the hose sprayer to ensure every inch of the inside got a good rinse. I then dicarded all the water and did a partial repeat. All water was removed from the bottom using a wet and dry cleaner.

I then half-filled it to use for washing etc but not drinking water or kettle just in case there was a slight taint.

As I couldn't detect anything by smell I tried a sip the next day, even though we don't normally use the tank for drinking water. I thought I could detect a very slight taint but it was so faint I wasn't sure if I might have imagined it. 

Once the water had gone down a bit more I filled the tank completely and went back to using it in the kettle and for cooking as, by this time, I could definitely not detect anything by smell or by taste.

For information I used Black Jack, 3 coats applied mainly by roller (apart from the corners/joins) and mainly from outside the tank using an extending handle bought from Poundland. The first two coats were each given 24 hours to dry before applying the next one.

[Bright Angel]

Hi all, sorry to butt in but someone might be able to help me out. After 8 years of having a rusty integral water tank with all sorths of wierd and wonderfull "ferrous" flowers growing in it, I finally bit the bullet, cleaned it out thouroughly, coated it with fertan and then applied 3 good coats of Black Jack "potable" bitumen. Filled it twice and drained it completely both times. Filled it again and got clean water. Have now just come back after 3 weeks away and the water has a distinct brown tinge with what looks like some organic material suspended in it, and it smells.

I am draining it again tomorrow. Should I use any bleach or similar to flush it out? What is the brown stuff, anyway. My water looked and smelt much better before I fiddled with it. Any help/advice appreciated.

[frangar]

24 minutes ago, Bright Angel said:

Hi all, sorry to butt in but someone might be able to help me out. After 8 years of having a rusty integral water tank with all sorths of wierd and wonderfull "ferrous" flowers growing in it, I finally bit the bullet, cleaned it out thouroughly, coated it with fertan and then applied 3 good coats of Black Jack "potable" bitumen. Filled it twice and drained it completely both times. Filled it again and got clean water. Have now just come back after 3 weeks away and the water has a distinct brown tinge with what looks like some organic material suspended in it, and it smells.

I am draining it again tomorrow. Should I use any bleach or similar to flush it out? What is the brown stuff, anyway. My water looked and smelt much better before I fiddled with it. Any help/advice appreciated.

How long did you let it dry before any water was put in? And was there half decent ventilation when it was drying? 

[Bright Angel]

Yes, about 2 days between each coat and the 2ft x 2ft cover was open all the time. I sucked out the last of the water each time with the wet and dry vac and blew it dry using the cleaners blower.

Some before, during and after photos. When I filled it for the second time I even let it overflow into the well deck and out of the weep holes to disburse the "oily" film on the top.

[frangar]

8 hours ago, Bright Angel said:

Yes, about 2 days between each coat and the 2ft x 2ft cover was open all the time. I sucked out the last of the water each time with the wet and dry vac and blew it dry using the cleaners blower.

Some before, during and after photos. When I filled it for the second time I even let it overflow into the well deck and out of the weep holes to disburse the "oily" film on the top.

If the weather was good...warm & dry....it should be left a good 7 days after the final coat before it was filled...longer if the weather was cool etc. 

[Bright Angel]

It was at least 7 days before I filled it finally and it was very warm. What do you think the brown suspension is ? I ran 2 glasses of water tonight, one from the hot and one from the cold. Both had a brown tinge but the cold fill also had foam around the top. Any ideas ?

[Sea Dog]

7 hours ago, Bright Angel said:

It was at least 7 days before I filled it finally and it was very warm. What do you think the brown suspension is ? I ran 2 glasses of water tonight, one from the hot and one from the cold. Both had a brown tinge but the cold fill also had foam around the top. Any ideas ?

Brown suspension sounds a lot like a bit of rusty sediment which is quite a likely thing after the work you've done. Have you fully flushed through at all taps (and calorifier, although that won't affect cold drinking water)? Do you have an inline screen filter before your pump (if not, you might think about fitting one to protect your pump) and have you cleaned it? Just a couple of ideas.

[blackrose]

You've posted "before and after" pictures, but what we can't see is the standard of your surface prep prior to painting. If you just painted over the rust with Fertan and bitumen without properly removing the loose rust then it will come back very quickly, and unfortunately all that paint is going to make the job much harder if you need to do it again. I've only ever used Vactan - is Fertan suitable for potable water?

Edited September 8, 2017 by blackrose

[nb Innisfree]

OP you say you sucked all the water out between coats, what water was that? 

[blackrose]

12 minutes ago, nb Innisfree said:

OP you say you sucked all the water out between coats, what water was that? 

My guess is rainwater - but the fact that paint was allowed to get wet between coats might indicate it was wet before it went off properly, which doesn't bode well...

[Tatguy]

Thanks for all your help it's  now sorted itself out smell has gone almost I didn't let it get wet between coats ivr also yested the water and als good

Thanks again

 

 

 

 

 

Yrs it was defiantly tank paint got it from the local marina did a coat waited 2 days did another then 2 days later did the final coat then left dry for 2 days closed and filled 

Since then I have steralise and changed the water 3 times and changed the water 2 more times in between 

Again the smell is still there 

 

[Bright Angel]

In answer to a few questions, Yes I phoned the manufacturers of the rust converted and they said that it was recommended for water tanks. No I didn't put any water into the tank between coats and I was in a covered dry dock so no rainwater got in. Yes I did drain the calorifier and all the pipes. Also I did prepare as well as I could. I first scraped out all the rusty sludge and removed it with a spade! I then pressure washed all surfaces exposing bright silver steel under the rust bubbles. I then wire brushed and re pressure washed. Finally hoovered out all the residues and water and then "blew" the tank dry with my hoover/blower. Left it overnight and did the rust coating before the bitumen.

Drained it out today using a spare bilge pump and noted a slimy brown coating on the baseplate, not rust residue. Cleaned it out with a soft broom and hoovered it dry. Added a dose of steriliser tablets, cleaned out the  pump filter and had supper!

Attached is the picture of the brown sludge in the cold water from last night. Any suggestions as to what it might be ?

[David Mack]

Are you sure the water you are using to fill the tank is clean?

[Bright Angel]

It was the drinking water supply in the boatyard then topped up with water from CART water points.

Would still be interested to find out what the brown stuff is.

[WotEver]

8 minutes ago, Bright Angel said:

It was the drinking water supply in the boatyard then topped up with water from CART water points.

Would still be interested to find out what the brown stuff is.

Looks like an algae growth to me. Bleach should kill it. Does it smell?