Are you on the hard right now? I'm assuming if a moisture reading was taken it was on the hard at the time, but that could have been last year when you purchased. Anyway, since its still cold in your neck of the woods I am assuming you have some time left before you'll be getting into spring sailing (maybe). If you are a handy guy this shouldn't be a hard repair as long your boat is on the hard and you can take the rudder off. I'm not familiar with exactly how your particular boat has its rudder post secured, but if its like most boats that size then it should be relatively simple. I've attached a link to a forum post on the repair to a Hunter 27 rudder; this repair is much more extensive than what you might need but it gives you some good insight;
http://www.sailnet.com/forums/gear-maintenance/62964-hunter-27-rudder-repair.html
- Take your rudder off and take it home if you can to work in a garage or shop.
- Scrape and sand off any bottom paint, use a sander that has a dust port to attach a shop vac (virtually no mess) and use a mask! Really clean off all the old paint, but not necessary to take off all the gelcoat.
- Drill some 5/16" holes in the high moisture area, hopefully the surveyor circled it for you. Drill some holes just below it as well and on both sides of the rudder. The holes do not have to go all the through rudder.
- Be mindful of the rudder post and internal skeleton, try to avoid drilling there. You might be able to find a drawing online to help you locate areas to avoid. If you feel your drill bit hit metal, stop! You won't hurt anything by touching metal with the drill bit, you'll just burn up bits if you keep pushing.
- Drill a few holes upward from the bottom, they don't have to be deep, maybe just half the bit length... be mindful of where the metal is as mentioned above. Hang the rudder vertical by the post.
- Your rudder needs to dry out.... for weeks... even months, depending on how much moisture is in the foam core. The BEST way to speed up this process safely is having it in a small room that stays relatively warm and use a dehumidifier! If you use a wood stove for home heating this also dries out the air well also. In a pinch you can use a space heater but watch it closely and don't burn your house down. Using a dehumidifier allows you to monitor how much water collects in the catch bin.
- After awhile drying out you can have the moisture test again, that's the best way to be sure... but really if you allow it at least 4 weeks, 6 if you can, in a space that is kept warm and very dry it will probably be dried out well.
- Fill the holes with epoxy resin. Apply a barrier coat, a 1 quart kit of Interlux Interprotect 2000 will do the job, roll on as many coats as you can get with 1/4" nap roller and use up the whole quart. As an alternative you can use 2 or 3 coats of epoxy resin as a barrier coat. Hot-coat it so you don't have to sand between coats. Prep-sand for smoothness and apply your bottom paint... Done, and you should never have rudder moisture issues again.
