The Rot Doctor


Subject: On removing moisture from a balsa core...
Date: Tue, 19 Sep 2000

I'm about to purchase a 20 year old sailboat (Freedom 28) - balsa cored hull and deck - and I'm quite willing to assume that there will be some areas where moisture has gotten into the core (of course, if there are huge areas, then I just won't buy it....).

Good thinking on your part. I'm sure you'll make this point of view quite clear to the surveyor. It's the biggest risk you take with this boat.

Here's the question: The point of the whole exercise is to remove the moisture and refix the skins to the core, yes?


And, of course, to minimize the chances of it happening again.


Now, I liked the idea of using a circular saw to make a series of cuts to expose some core area, then letting it naturally dry or using a hair dryer to help it along. Do you have any thoughts on using a small vacuum pump (instead of hot air) for moisture removal? Maybe I'm missing something, but I would think that it would be faster.... and maybe more complete.
Comments appreciated,


You're right about the vacuum pump. A big pump will remove a lot of moisture fast, and a small one will just take longer. This is done by yards for exactly the purpose you describe. Positive air pumps will remove moisture as well, but not quite as efficiently. If you run into the problem, then go for it.

If you buy this boat and if you run into the wet balsa problem, I'd be interested in hearing about it, and how you go about fixing things. And feel free to ask us for opinions...if we can help, we will.