Tony-B
Posted: Thu Sep 22, 2016 7:14am
Post Subject:
Hull thickness
I can assure you that it is not a silly question. The only silly question is one that is not asked but an answer is required. Much depends upon the quality of the steel and other factors. A 12mm base plate will be heavier than a 10mm one so the hull will need less ballast. This will allow the builder to fit a lower floor if he chooses so if you are tall it would give a greater headroom, especially important if the design has any side passages. Steel comes in a number of grades and some probably come with no grade at all. Unfortunately I do not know enough about the various steel grades to give you BS or EN numbers. The thing about graded V ungraded steel is that with graded steel there is a far better chance of the quality being consistent. This means that a choice between 10mm graded steel suitable for hull work V 12mm ungraded steel may make the 10mm a better and possibly longer lived option. I fear you will need to do research into steel grades. Springer boats were originally built with the equivalent of 4 or 5mm base and many are still in use maybe 40 to 50 years later. Dutch motor cruisers are often built from 6mm steel while 6 or 8mm base plates have been very common in the past and they are still in use, some I believe on hire boats but the hire boats have probably had work done to reinstate the wearing edge of the baseplate. Typical hull specifications are 10mm base, 6mm hull sides and 4mm cabin sides and roof. It is almost certain that the 6mm sides will require plating long before the 10mm base, especially if you do not keep the hull coating in good order. If the steel quality is the same 10mm is perfectly adequate but 12mm is nice to have, especially if you are tall, and as so many people think thickness is all that matters will probably give you an advantage when it is time to sell.
