Water tank lining

[Bobbybass]

Hi all.

 

I need to line my water tank. I scraped the rust last year and used a Thomson potable 'bitumen type '  coating which said it went direct to metal, but its getting rusty again.

I did a thorough job  (as much as I could ) , drying it out and Hoovering the dust out. The dust had absorbed any left over moisture as well.

 

I have looked at various rust treatments, but they say..."Not for potable tanks "  so I didn't stabilise the rust

 

I 'think' I need to line it, but how do I go about that ?.

 

Its a sort of 'cheese shaped' space that is the entire bow of the boat, so who would make this up and how do I fit it ?

 

Thanks. !

[Boater Sam]

Bitching a tank is a tough job. I do mine when the boat is out of the water as I found that before applying bitumen  I could neither get it really dry nor stop condensation forming as soon as I got inside. With cold water outside its an impossibility.

I hang a mains light bulb in there for a few hours before starting to paint so that the steel is fully dry.

Doing it this way I find that 2 coats on scraped steel wiped over with white spirit immediately before painting last over 10 years without serious rusting.

 

Liners or bag tanks are made to fit but its tricky putting the filler and outlet in the right places. We used them on day boats and they regularly failed after a few years where they creased when empty.

 

Water purification tablets accelerate deterioration of bitumen I found.

[dor]

I would be more concerned about the sealing of that hatch than a bit of rust appearing on the inside surface.

 Never understood why builders make the water tank so easily contaminated.

[Arthur Marshall]

I put a heater in mine a while, then gave it two coats of bitumen. But I did it on a few hot dry days in summer - wouldn't even try it this time of year. Only had to do it twice in thirty years. 

[Bobbybass]

36 minutes ago, dor said:

I would be more concerned about the sealing of that hatch than a bit of rust appearing on the inside surface.

 Never understood why builders make the water tank so easily contaminated.

Thanks...

 

I have a rubber seal around the hatch...

[jacko264]

Excuse my ignarance but could it be fibre glassed out  

graham

[WotEver]

Just now, jacko264 said:

Excuse my ignarance but could it be fibre glassed out  

graham

The likelihood is that moisture would be trapped between the GRP skin and the steel, so the steel would quietly continue to rot and have no access to attend to it. 

[jacko264]

Thankyou for your reply and now I understand 

graham