Frozen mahogny
Dead wood on Meritaten got the beating during her 60 years of service.
For clarity - dead wood is a part of the bottom which acts as a spacer between ballast keel and the hull (in the meaning hull=enclosed, non-water-filled space). It’s called dead wood since it is constantly immersed in water and it’s only function is to be a spacer.
Like a dead wooden log.
Unlike the rest of underwater hull, this part is saturated with water on all sides. This makes it very sensitive to freezing if the boat was pulled out too late before winter.
Apparently there were a few times in Meritatens life that this happened.
The problem with this is that the wood is getting cracks and is deformed. It also allows water deeper and deeper in it’s structure, eventually corroding ballast bolts which run through it. While bronze screws feel comfortable in stagnant, sea water - Meritaten is not so lucky to have them.
Bronze cannot be used with steel ballast due to galvanic action between them. Meritaten has steel ballast hence she uses galvanised steel bolts. They do not like sea water.
Anyway - apart from this major problem - such affected wood does not hold bottom paint well. Every autumn the paint flakes and fells off in such places.
The only permanent fix for this problem is to replace dead wood with new structure. Unfortunately it is not a trivial job, requiring dropping the ballast keel and removing garboard plank (the first plant on the bottom, meeting the wooden keel, floors and all the frames). While fixing dead wood - with all the preparations required - people usually chose to do even bigger restoration like replacing the wooden keel, replacing ballast bolts, reframing the boat (if needed) and changing the floors. That’s a “biggie”!
I got a price offer for this job on Meritaten: 400k SEK. And it is not the material that costs - it’s man-hours.
In my ears it sounds a tad expensive and means only this:
I will need to do it myself.
Until then - Thomas Larsson estimated around 10-15 years of service - one can try stopping or slowing down the deterioration. The way used here is to oil the wood with clan, cold-pressed linseed oil.
There are advocates of diluting oil with turpentine which shall enable deeper penetration into wood. According to Wooden Boat articles, however, this is not true.
Besides - having turpentine in the mixture disables the possibility to use hot oil. Really hot oil.
I’ve removed all peeling bottom paint and partially primer, to reach the wood.
Oil was heated up to 120 degrees C which brings it’s consistence to water. I’ve applied it in generous strokes with cheap but natural-hair brush, king-size (synthetic brush might not withstand these conditions - and it’s more expensive).
Procedure was repeated for several evenings in a row. After each session all raggs which were soaked with linseed oil were burned or sealed in water-filled containers. The reason is that oxidising linseed oil can self-combust - and it happened many times in the past.