Do plastic boats really soak up water.

[Tranona]

Why dont all premium boat bulders like HR build the whole boat out of epoxy. Its stronger and much more water resistant.
Epoxy is more expensive than polyester, but the hull cost is only about 1/3 of the total cost so the aditional expense is not enormous.
No teak decks and an epoxy hull would make it a much better boat for the same cost, IMHO.

Several builders (Hanse and Elan of the top of my head) have offered the alternative of epoxy boats, but it does not seem to have become very popular. If there really was a clear proven superiority that could enhance the sales of boats then builders would be more enthusistic about offering it. At the moment it would seem that buyers do value teak decks (and many other non essential features) more highly.

There is no doubt that materials and processes have improved enormously over the past few years and maybe potential buyers do not see the benefits of epoxy laminates being worth the extra cost.

There may well be individual failures of polyester hulls, but would suggest it is not systemic in the same way as it was with hulls moulded in the 1970s to 1990s.

 

[Blueboatman]

Hang on. There are other issues with epoxy. It is less tolerant to heat which might prove interesting even in typical tropics temperatures. Something to do with it softening iirc. Which affects it's engineered properties.
And we all know about the uv issues.
Was certainly frowned upon for wood mast building- or have epoxies really come on in the last 10 years? One for a currently active mast builder to answer perhaps?

 

[Quandary]

I don’t share your faith that modern resins are not vulnerable to Osmosis. I have seen a lot of reasonably modern boats having Osmotic peels. Last time I was on the hard the 5 or 6 year old Jeanneau next to me was having it done.

Finngulf have been making yachts since 1981 without any reported problems of blistering, they use an isopthalic gelcoat with a clear top coat below the water line specifically to resist moisture penetration. I convinced myself before purchasing that their quality control was sufficent and that they were serious about their warranties. They maintain the history of every boat they produce which I suppose is easier for a lower volume boatbuilder. They do offer an epoxy resin option on some hulls but this is marketed for weight reduction for high performance with no difference in the hull warranty. It is very expensive because the whole epoxy resin hull is oven cured at 55 degrees for more than 24 hours after lay up, this adds a lot more cost than the resin price difference.

 

[Ricd]

Of course plastic boats soak up water that's why every competitor at the sailing Olympics next year will have a brand spanking new boat...because it will weigh less than last years brand spanking new boat.

 

[xyachtdave]

+1

Guapa recently spent 2 years on the hard whilst in refit.

Moisture readings were taken when she came out of the water and again just just before she just went in. The readings were virtually identical.

That is scientific enough for me!

Leaving a boat out of the water for a few months to dry it out in freezing temperatures...not a good plan me thinks.

Also surely the hull is warmer in the water than out and supporting the weight of the boat as the design intended in the water, not stuck on a couple of props, must be better for it?

 

[Rivers & creeks]

Just wondering if winter weather is a lot less humid - except when it's raining

In fact I'm sure the air is generally less humid and therefore more able to dry out a boat.

 

[Ricd]

In absence of significant temperature difference the only way the hull will dry is if the air is carrying less moisture than the hull. At lower ambient temperatures this may well be the case. This moisture difference does not need to be greatly different as mass transfer should ensure the wind continues to remove the saturated layer of water at the hull air interface which is then replaced by drawing moisture from the hull ...I guess this continues until the hull and ambient air are in equilibrium. After all this is how the washing dries on the washing line on a windy winter day albeit slowly....this all of course could be complete cr*p