Wednesday, 12 September 2012

DIY narrowboat blacking for beginners.

We decided to tackle blacking Freyja and Christina ourselves, but how do we go about it?
After searching through a lot of forum posts and googling for tips and an idea of the quantity of bitumen required for two narrowboats, we were still not sure how much we'd need.

Ask twenty narrowboaters how to black a narrowboat and you'll get ten that say you have to apply it with a brush and five that swear by a roller and the others that spray or use a combination of the above. No-one can agree on what is the best product or how often you should re-black, anything from two to five years.
Don't get me wrong, there's a lot of advise to be found out there, it just seems there is not one, that we have found, sufficiently detailed to help us buy the right quantity.

We decided to buy standard bitumen and searched DIY stores with not much luck, B&Q had none, but were cheap for value white spirit and stiff 5" stiff masonry brushes, round masonry brushes, rollers, long-reach rollers and scrapers.
Homebase seem to stock only two 5 litre cans per store (at £20.40 each)
We then tried Ridgeons builders' merchants, they stock 22.5 litre drums and 5 litre cans, so we bought one of each, we want to apply two coats to the 108 foot of length of our boats.
Only time will tell if we've over or under estimated the quantity needed.
This is what we bought :-


2 x 5" stiff shed & fence brush @ £3.08                                                                £6.16
1 x stiff round masonry brush                                                                                £4.98
1 x 5" stiff masonry brush                                                                                      £6.00
1 x roller on a pole                                                                                                  £5.00
1 x value roller & tray set                                                                                        £3.00
1 x tungsten scraper                                                                                              £9.18
1 x pack of tungsten blades                                                                                   £7.18
                                                                                                    Total                  £44.50


1 x 22.5 litre Cementone black bitumen                                                             £81.00
1 x 5 litre Cementone black bitumen                                                                  £22.68
1 x 2 litre white spirit (should have bought the value white spirit from B&Q)       £5.94
2 x disposable hooded overalls @ £4.75 + vat                                                  £10.27
2 x Safety spectacles @ £3.25 + vat                                                                   £7.03
                                                                                                     Total                       £126.92
                                                                                                    Grand Total             £171.42

We already had ;-

A box of disposable gloves
Workshop tissues
A sack full of old towels
Hand cleaner
Old boots, hats and clothes to wear under the overalls

We are open to suggestions, if you think we've left anything out or bought the wrong stuff.

P.S.  Enough of the 27.5 litres of bitumin paint remained and was used to re-paint Freyja with one coat up to the rubbing strake, a second coat to just above the waterline and a third coat around the waterline, plus painting the new rudder, and repainting the weedhatch and cover.(don't forget to do this, as the inside of you weedhatch and the inside of the lid will also be under water)  
So 10 litres would be more than ample to black a 55 foot narrowboat.

A quick update. At the end of January 2016 we hauled our  53 foot butty Christina out onto the slipway at our marina. we were taking a chance weather wise but it was agreed that we could stay longer than a week if needed, at no extra cost.

Once out, we quickly scraped all of the growth off the hull and jet washed it (this needs to be done as soon as the boat is out of the water, it becomes much more difficult once the algae etc. has dried). It was noted that the rubbing strake on the waterline had not been continuously welded and rust had built up behind it causing it to jack and buckle out. We bought six metres of D bar and got Bruce to cut out the bad bits and weld in the new. We also found bad welds on the box section on the bow. On cleaning the welds up we found this to be full of water. so we cut it out and welded a section of D bar in.
We had some old bitumin left and I bought a 5 litre tin from Tool Station (they only had one tin).
Searching online I found a 25 litre drum for £46 odd, delivered. Briefly wished I'd bought 5 x 5 litre tins from Tool Station but soon realised that the plastic barrel made pouring and re-sealing much cleaner and easier. In between coats, wrap the brushes and roller heads in some clingfilm they will then be ready for use the next time without the need to clean them.
How did we get on?
I first used the old and thick bitumin all around the elum (big wooden rudder on the butty) stipling it into all the pits and awkward bits. 
I used a grinder with a rotary brush to clean the hull a bit better. I then brushed a thick coat of the Tool Station black around the hull, stipling and then smoothing it in.
When the 25 litres arrived, I started using a roller to add three more coats, leaving 24 hours between each coat. The 5 gallon plastic drum was great, easy to pour into the roller tray, and with no mess. As it is cooler at this time, we'll leave it a few days to harden before putting her back in the water.
If you have any bitumen left over and time before your boat goes back in the water, put a few more coats to just above and below the waterline.
N.B. Be careful not to paint bitumen anywhere where you want to apply normal paint, as bitumen can not be overpainted! So keep it off your tunnel bands and gunwhales.
I'm using these days to re-instate the tunnel bands (as they had been shortened at some time) I've also added a butty-style curved tunnel band below the rear rubbing strake. 
If you didn't wear disposable gloves, clean your hands with baby oil or baby wipes.
 ( Nigel, the seller of the bitumen drums, is an absolute diamond! The next time I ordered 25 litres the courier failed to deliver the second drum, he moved heaven and earth to deliver to me and offered a refund with me keeping the drum! I was very happy with his service the previous time and refused the refund, as it was the couriers who were at fault)
Mask around the edges of your anodes with any kind of tape or even clingfilm, this saves having to clean splashes off (as any blacked bits of anode won't be effective)
I found it better to remove all the blacking from the top rubbing strake and gunwhale sides, this was then painted with matt blackboard paint, this is very easy to touch up and blend in, if/when it gets scratched!!


  1. Hi Chop,
    Im just about to black my boat and was wondering how the cementone bitumen you used is holding up is it anygood ? Cheers, John.

  2. Hi John
    Sorry, I've been on tour and only just read your question.
    When we dry-docked Freyja, after one year (To replace the rudder etc) the blacking had stood up quite well apart from where I scraped some off on the way South!
    We gave her a couple more coats and there is still some left to do touch ups ;o)
    We used paper overalls over old clothes and shoes or wellies. Baby oil is the best thing to get it off your skin!
    Good luck with your blacking, let us know how you get on.
    Chop & Glenda