A fun subject and a fun task, hull protection is necessary if we wish to protect our investment long term.
The reasons behind the need to protect the hull are simple but the corrosion mechanisms themselves are complex. Further reading on the subject can be found in our sections on Anodes
and Galvanic Isolation
in our Electrics chapter above. Aside from galvanic corrosion, we talk a lot about the harsh day to day life of the canal boat hull. For some of the year it sits immobile in often dirty or oily water. For the rest of the year it is bashed and battered about in locks and against mooring
Therefore, coatings are applied to prevent corrosion of the steel and there are two basic application methods:
1) Hot sprayed metal coatings have been used in the offshore marine industry for many years and now this technology is available to the inland waterways boat owner.
2) Conventional brush or roller cold applied systems that are considered integral with anode attachment to the overall protection system.
If you’ve read our Anodes
piece you will be aware that anode manufacturers advise on a 3 year scheme of protection. For most owners that coincides nicely with the re-coating of the hull, which also seems to need doing at around this interval.