Today was the day I finally put my vacuum setup to work on MaJic Carpet. It took a bit of setup work to put all the little puzzle pieces together but I wanted to let all of you know that science is a good thing. I've known for sometime now that I could warm the hull pretty dramatically with a two burner Mr. Heater that I have. It is an infrared propane type burner. Today with ambient temperatures at about 55° I was easily able to get the surface hull temp to 200° and in fact even turned the heater down some. With the exterior at this temp the interior surface readings were about 80° so I was getting substantial amounts of heat into a very soggy part of my hull.
Within about 15 minutes of turning the vacuum pump on I was seeing moisture condensing in the vacuum line leading to my water collector. As I had suspected in the area I was working, I was only able to draw about 17 inches of Hg. and the pump is capable of doing nearly 25 inches of Hg. So the atmosphere is moving through this balsa, probably through the glass itself and the various small leaks in my setup. But as it moves it is picking up the moisture and taking away from the core.
I have no idea how long it would take to fully dry an area at this point. But the ramifications of this working are pretty substantial. In the case of my boat I had always planned on re-skinning the entire hull, but the fairing process will be much, much easier if I can leave the existing skin in place and do an appropriate repair for the saw kerfs and then cover the entire hull with new glass. As far as I can tell my balsa is also still pink, so when it is dried it should have the strength characteristics needed to maintain a very stiff hull.
I'm uploading a short video now that should be available in the next hour or so.
Vacuum Drying Balsa Core I plan to run the setup all day tomorrow and and then will peel everything back and test the area with my moisture meter. I can take readings without peeling everything back, but I think to see what change has happened accurately I need get to the bare hull. If the readings tomorrow evening are still very high when reading through the plastic and breather cloth I may wait another day. In either case I will report results tomorrow evening.
