Good Mastic for clinker seams

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Re: Good Mastic for clinker seams

Post by Keith66 »

I have spent most of my career working & mending boats many of them clinker built, I also rebuilt quite a few. The practice of "Hardening up" existing fastenings is more often than not a short term fix & rarely works.
Copper fastenings corrode & waste away, forming a crust of verdigris as they do so. In mahogany planked boats the fastenings seem to corrode quicker than in pine planking. I have worked on YW Dayboats & tideways whose nails were approx 30% corroded below the waterline, Yet a Rye beach boat planked in spruce & built in the 30's showed little wastage.
If you have a boat that is relatively new hardening up may work but on a 40 year old boat that is leaky & whose seams are full of dried paint & possibly mastic of unknown provenance you are wasting your time, trying to harden up an old nail that is loose in its hole is likely to just buckle it.
Better to refasten it with new nail, at least then you can go up a guage if needed so its a good fit in its hole.
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