** Update 27th July, 2018.**
During last summer, the heat of the sun on the hull and the cool of the interior of the water-tank caused a lot of the coating, previously discussed in this post, to flake off.
This left flakes of toxic residue in my water and made it unsuitable as a potable water source.
As an alternative to climbing into the water-tank and getting myself covered in toxic bitumen water-tank paint in the blazing hot summer sun, I decided to try another suggested solution for the coating of watertanks on narrowboats, that would be VACTAN.
A water based product. Instead of bitumen, it applies a latex anti-corrosive coat to the watertank.
The advantages of VACTAN vs Rylards Water-tank coating
|Preparation||Remove lose materials and residues||Remove lose materials and residues|
|Number of coats||1||2|
|Time between coats||1hr||8hr|
|Type||Water based||Bitumen based|
Below, there are 5 steps to coating your water-tank.
To amend that.
- Strip the loose and decayed metal (#1)
- Apply VACTAN (#4)
- Flush the residue (#5)
If you decide to use one of the other coatings, then you need to take the steps below.
I’ve made a short video about my experience in applying VACTAN and some of the practical observations about using the product.
Painting a narrowboat water-tank, old version
This little story is about how to paint a narrowboat water-tank:
There’s 5 steps
- Strip the loose and decayed metal
- Work surfaces down to bare metal or non-corroded paint
- Apply Iron Oxide paint to areas still rusting
- Apply bitumen blacking paint
- Remove paint residue
Stripping and prepping (rusty tank) – 2days
Painting (1 primer and 1 top) – 2 days
Total – 4-5 Days
*This is doing it fast. If you want to paint the tank in two halves it’s going to add a day.
Paint – £15-£20
Brushes – £15 -£20
Total – £40
Step #1:Strip loose and decayed metal
Shave-hook – Triangular headed scraper
Located right at the front of the boat, the water-tank has been rusting for a while. The paint has come off over time leading to corrosion and a build up of sediment at the bottom of the tank.
Using the triangular headed scraper, or shave-hook, (as it’s officially known), I stripped the inner tank of any of this loose material.
There was perhaps 3kg.
I also had to DRY THE TANK OUT and remove ALL OF THE WATER.
This I did with some sponges, then left it to dry.
Step #2: Work surfaces down to bare metal or non-corroded paint
Small wire brushes
Bosch PSB 680 Compact Drill
Crimped wire brushes
Mask + Goggles + Plugs
Actually getting down into the tank.
Ensuring that all the rust is removed from the seems, where the welds are made.
All areas where the paint has come off is reduced to bare metal.
This took a period of about 9 hours in total.
It’s no small job.
You will find you and your tools are covered in sticky grime, I would recommend covering up, I’ve featured the bare minimum of PPE you’re going to require.
Step #3: Apply Iron Oxide paint to areas still rusting
Iron oxide paint
Getting back into the tank.
Vacuum out with a small handheld 12v Bosch vac, I also wiped the walls down with a damp cloth.
The red oxide is essential to prevent further corrosion. Don’t use any other type of primer.
Priming the area where metal is showing.
Takes about 2-3 hours.
Step #4: Apply bitumen blacking paint
Rylard watertank coating.
The regulations concerning water-tank paint coating have changed…
Into the future, all bitumen based coatings are to be phased out.
If you have bitumen ALREADY in your tank, this is the only coating you can apply under current EU health regulations.
Climbing into the tank with a large 4″ paintbrush.
I actually poured the paint into an old Fray Bentos pie tin, something you may or may not have lying around….
Initially, I would have said 1-2 hours, but to get full coverage. Working into all the pits and seems. Takes about 4 hours.
I’ve applied two coats.
The best way, if you’re not able to do it in one go,which will involve some physically demanding work, would be to paint one half, leave to dry, then paint the other.
You need two coats. One will not do.
Step #5: Clean residue.
This isn’t one I expected.
There is, however, a fair amount of small paint particles and residue that need to be removed before the water is drinkable.
Simply a case of filling the water tank, mopping down all the sides with a clean mop.
Emptying leaves the particles on the side of the tank which can then be wiped off with a damp towel.
You can use Milton solution.
You may have to do this routinely, if you want to use your water tank for potable water.
Leaving the milton solution to soak for the recommended period, 4 hours, then emptying the tank after flushing round your system thoroughly.