Can osmosis be worse in med waters?

[Zagato]

Are boats which come from the Med more liable to get osmosis sooner than UK one's? I am looking at a boat which spent the first 5 years of it's life in Greece. I presume they don't get lifted out during the winter also. I wondered if warmer water makes a difference! It was epoxied from new apparently...

 

[Lakesailor]

But on the other hand, is it saltier? Fresh water exacerbates osmosis.

 

[Tranona]

Are boats which come from the Med more liable to get osmosis sooner than UK one's? I am looking at a boat which spent the first 5 years of it's life in Greece. I presume they don't get lifted out during the winter also. I wondered if warmer water makes a difference! It was epoxied from new apparently...

Would not worry about it. Osmosis is much less common on boats built since the 1990s, and if it has been epoxy coated, even more unlikely, which is why the treatment is used. My boat spent 10 years in Greece and no osmosis. The only boats out there you see with it are old UK boats that are prone to get it anywhere.

Your surveyor will check it out anyway.

 

[macd]

I presume they don't get lifted out during the winter also. I wondered if warmer water makes a difference! It was epoxied from new apparently...

Lifting: a false presumption. Many are lifted out, but it's well worth checking if the boat you're interested in is one of them.

Most chemical processes will be faster in warm conditions but, as Lakesailor states, more salinity = less osmotic pressure. The Med is very salty.

 

[Elessar]

Are boats which come from the Med more liable to get osmosis sooner than UK one's? I am looking at a boat which spent the first 5 years of it's life in Greece. I presume they don't get lifted out during the winter also. I wondered if warmer water makes a difference! It was epoxied from new apparently...

all these guys are right. worry about something else. epoxy is 25x more waterproof than gelcoat if it's been done from new........

 

[noelex]

Many boats in the Med are lifted out for winter. This is a very big help in reducing osmosis. Saltier waters help, but warm waters are more significant in making the problem worse, so be careful of boats that have been left in the water.
Lots of modern boats have osmosis, considering the incidence rises as the boat ages modern boats seem just as prone to the problem.

 

[wotayottie]

Are boats which come from the Med more liable to get osmosis sooner than UK one's? I am looking at a boat which spent the first 5 years of it's life in Greece. I presume they don't get lifted out during the winter also. I wondered if warmer water makes a difference! It was epoxied from new apparently...

All chemical reactions go faster in warmer temperatures. But the Med is saltier than most sea water because of evaporation. So yes - osmosis is more on an issue there than here.

 

[Zagato]

Thanks for the replies. I always thought fresh water from lakes/rivers etc didn't give osmosis problems whereas salt did - got that wrong then. I have even heard people say that if a boat is in a creek it is less likely to get osmosis becuase of the fresh water from the river diluting the sea water

Shouldn't be anything to worry about from what you say

 

[vyv_cox]

Looked at simply, the cause of osmosis is that a cell (in this case some porosity in the hull of the boat) contains a solution of some water soluble salts. It is separated from the bulk supply of water by a membrane, in this case the gel coat. Bulk water 'tries' to dilute the cell solution to achieve the same concentration inside the cell as outside it. Bulk water with no dissolved salts will provide a higher concentration gradient than water that already contains some salt, thus will give higher osmotic pressure.

 

[Elessar]

Looked at simply, the cause of osmosis is that a cell (in this case some porosity in the hull of the boat) contains a solution of some water soluble salts. It is separated from the bulk supply of water by a membrane, in this case the gel coat. Bulk water 'tries' to dilute the cell solution to achieve the same concentration inside the cell as outside it. Bulk water with no dissolved salts will provide a higher concentration gradient than water that already contains some salt, thus will give higher osmotic pressure.

In this case epoxy acutually. Osmosis occurs only if there is a semi permeable membrane, like gelcoat.