Here is the extent of the removed balsa. You can see by the strips at the upper right how much I was expanding with each cut. The moisture was mostly against the lower laminate and when I no longer found structurally compromised wood, I stopped. Well, first I drilled some outlying holes to examine and, since they were okay, I stopped. I decided not to remove the core to the black hole at the top of the picture because the wood in between it and my major area was okay even though wet. The moisture reading in the wood was 37%, which is basically saturated but not dripping wet.

This shows how the balsa core can form little paths for water. This piece is actually upside down from how it sat in the hull. All of this is stained but still structurally sound. The little hole is from being poked with my moisture meter, not termites!

Another picture of the removed balsa showing the scarf joint preparation for connecting the new epoxy/glass top laminate. I knew that there was a reason I hated fiberglass boats. Grinding down the glass was horrible. Also shown is a 160 degree heating pad that is moved around over the cockpit sole to drive out moisture. I also used heat lamps under the boat. Be careful with those. They can get very hot.

I put the seat box/cockpit panel back in temporarily so that I could work on other projects. You can see that the pop rivets at the aft of the port seat box were the primary problem. They are spaced closer together, so the moisture did more damage. There are five or six other rivets where the balsa is bad, but those can be fixed without removing the fiberglass. Actually, the reason I put the panel back in is to measure for the Tempress access hatch that will be covering my heater, if all goes well.

Here is the extent of the removed balsa. You can see by the strips at the upper right how much I was expanding with each cut. The moisture was mostly against the lower laminate and when I no longer found structurally compromised wood, I stopped. Well, first I drilled some outlying holes to examine and, since they were okay, I stopped. I decided not to remove the core to the black hole at the top of the picture because the wood in between it and my major area was okay even though wet. The moisture reading in the wood was 37%, which is basically saturated but not dripping wet.

And the edge of the balsa still in the boat is only down 10% (in the first 2 mm). A long way to go. I'm thinking months in a heated garage while applying heating pads and heat lamps. That's not practical for most boat owners.

I am still a long way off from what my replacement balsa shows. And I am forced to guess how the balsa is drying out between the laminates where I can't get a reading with this meter.

So I tore off the laminate and tested the interior of the plug. Higher than the exposed wood, but still way down from the original 37%. It is kind of amazing how fast balsa can dry out. A stick of red alder, which I use for smoking salmon, would take several months to dry out like this.

M

Here is the extent of the removed balsa. You can see by the strips at the upper right how much I was expanding with each cut. The moisture was mostly against the lower laminate and when I no longer found structurally compromised wood, I stopped. Well, first I drilled some outlying holes to examine and, since they were okay, I stopped. I decided not to remove the core to the black hole at the top of the picture because the wood in between it and my major area was okay even though wet. The moisture reading in the wood was 37%, which is basically saturated but not dripping wet.

Marco Flamingo
Oct 5, 2015

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