bob_t

You would also probably be surprised how much weight your boat has gained due to water absorption, if it is kept in the water all of the time(which it sounds like it is). The barrier coatings ( aka bottom paint) help to slow the absorption as well as retard growth (nothing grows well in contact with copper compounds). In general, gelcoat is not 100% waterproof. Some may still remember the Donzi "blister boat" from the very early 2000's on this website. That boat sat in the water all season for a couple of seasons/years and looked worse that someone with very severe chicken pox That boat developed blisters, but it can also just absorb into the materials without the blisters.

DracoDan

Thanks, while I know that no boat is impervious to this sort of thing, it's a 1999 that has spent its whole life in the water. I bought it last year and had a survey done on it and the surveyor didn't find any signs of rot. I know I know, that doesn't mean it hasn't absorbed water, it's impossible for it to have NOT done so... That being said, there's no way that I aware of to fix the affected wood without replacing the hull. I don't expect it to last forever, but if its made it this long I doubt me storing it out of water is going to make any discernible difference.

bob_t

Wasn't referring to wood rot. Just the fact that when they sit in the water for extended periods of time (years), they can gain weight from water being absorbed into the laminate. Sort of like the matress commercials you see on TV. Wasn't implying that your boat has rot, or is rotting, just another source of added weight that could slow it down over time (years). If it happened in one year's time, I doubt it is from gaining weight. Probably more of the growth stuff that the others were saying.

DracoDan

In a nutshell, that is what I was implying... Yes, the slowdown happened in one year. I don't see how laminate would hold water though - the way I understand it is that he laminate allows water into the wood core, which then acts as a big sponge.

bob_t

You can google " water absorption in fiberglass" and read lots about it, if you are interested. In general the weaves and resins are not completely hydrophobic. The wood is hydrophillic, and uses that "humidity" to start rotting, over time ... and depending upon how good of a job the builder did, and what wood/treatment of the wood, it can be a really long time before it rots. A lot of builders don't go back and coat the id of the thru holes they bore for engine mounts, transom assembly bolts, the bolts for steering ram attachments, etc, and those can allow direct impingement to the wood and then the rot starts to spread like termites. The barrier coatings do a good job of blocking absorption, in addition to retarding growth for boats that continuously live in the water. Just trying to give some helpful information that may be useful, or may be not, for your question.

dereknkathy

the slowdown occured in one year. the seller had bottom clean and shiny when you bought it. i'll bet the slowdown occured EVERY year until bottom was defouled. you say it isn't salt water. makes it harder to beach it and let the tide run out and scrub it. you can get a lot with a long handled brush from the surface. borrow a rowboat...