Ryan,
Is there any moisture at all present in the bilge area where the panels are becoming tight? I would check the hull surfaces and the underside of the floor. Are you taking your humidity readings at the level of the floor or higher up in the cabin? I am guessing that you are heating the boat to well above the current temperature of the water? If the instrument that you are using to read off the relative humidity is well above the floor then the relative humidity in the bilge could be much higher. For instance, if you are reading 20C and 53% relative humidity in a location several feet above the floor level, that same air when cooled to 10C in the bilges from the cold water will be at saturation. (100% relative humidity) I am confused as to why drying the panels did not seem to help but perhaps the floor itself has swelled enough to create the fit problems? This is a hard problem to troubleshoot from a distance but in general I usually find that when wooden parts fit properly when the wood is known to be dry begin to become tight that moisture/swelling of the wood is usually the culprit. Perhaps the reason that the panels are the tight only in the main cabin is because the cabin sole is because the athwartship dimension of the total panel is the greatest in this area of the boat hence more total swelling. I assume that you have checked to be sure that the panels are being inserted into the correct location?
It might be worth taking a feeler gauge and checking to see where the panels are actually binding since that might provide a clue as to what is going on. See if there is a pattern that repeats when comparing the Port and Stb. side. I don’t know how long your lift out panels are but if wood swells unevenly you can end up with a curved shape that might show up from taking a few measurements. The feeler gauge will also show you the tight areas that you will need to trim if it comes to that...
Best of luck,
James
SV Sueno, Maramu #220
James,
I removed all the floor panels and dried them out by propping them up around the saloon for 4 days. The temperature never went below 50°F/10°C and humidity was never above 50%. It doesn't seemed to have changed anything. They're just as hard to fit as before, to the point where I'm afraid to jam the last one in; I might need to use a crowbar to get it open again. So I have the one at the forward end of the saloon sitting 90 degrees off from where it belongs... there's only a minimal risk of breaking an ankle.
Any other ideas?
Thanks,
Ryan
SM 233 Iteration
Boston, MA, USA