Sailfree
Well-Known Member
Seeing the post on Westerlys do modern boats built within the last few years still have an osmosis risk or is it more a quality risk of voids in the layup during building?
New Boat Osmosis
- Thread starter Sailfree
- Start date
Norman_E
Well-Known Member
All GRP hulls have an osmosis risk, it it just that the more modern gelcoat resins have a greater resistance to water intake, so the problems are likely to be less, and later in the boat's life. Osmosis occurs when a weak solution (seawater)and a stronger solution (a styrene solution formed when water is absorbed by the resin underneath the gelcoat) are separated by a semi permeable barrier (the gelcoat). The less permeable the gelcoat, the better the osmosis resistance. That is why some owners epoxy treat the hull prior to first anti-fouling.
Epoxy hulls are now being touted as safe against osmosis.
Epoxy hulls are now being touted as safe against osmosis.
andy_wilson
Well-Known Member
Generally hulls are now moulded with the benefit of considerable hindsight.
This includes ortho-something resins (that are more resistant to water) for gel-coat and outer layers - including pigment free below the w/l, a special layer of mat in the first layup after the gel coat to resist wicking, consistency of production line techniques, better quality control of materials, better temperature control of processes.
Some manufacturers use special wetting out techinques or vacuum bagging to eliminate voids.
All the above point to improved osmosis protection.
Counter that with less material used in the build - lay-up levels have generally dropped since the early days of 'slap another layer on just in case'. Counter THAT with advanced designs with internal grids to spread the load. Counter THAT with more potential hassle in the event that a repair is required to, say a keel stub.
I would suggest that on newer production hulls, the risk has moved away from osmosis, but towards the structural issues. Witness the the way Bavarias seem to have been shedding keels lately (runs and ducks the incoming flack!).
NOT that this hasn't always been an issue, Westerly Centaurs have nearly all had keel stubs reinforced for instance.
This includes ortho-something resins (that are more resistant to water) for gel-coat and outer layers - including pigment free below the w/l, a special layer of mat in the first layup after the gel coat to resist wicking, consistency of production line techniques, better quality control of materials, better temperature control of processes.
Some manufacturers use special wetting out techinques or vacuum bagging to eliminate voids.
All the above point to improved osmosis protection.
Counter that with less material used in the build - lay-up levels have generally dropped since the early days of 'slap another layer on just in case'. Counter THAT with advanced designs with internal grids to spread the load. Counter THAT with more potential hassle in the event that a repair is required to, say a keel stub.
I would suggest that on newer production hulls, the risk has moved away from osmosis, but towards the structural issues. Witness the the way Bavarias seem to have been shedding keels lately (runs and ducks the incoming flack!).
NOT that this hasn't always been an issue, Westerly Centaurs have nearly all had keel stubs reinforced for instance.
WayneS
Well-Known Member
[ QUOTE ]
Witness the the way Bavarias seem to have been shedding keels lately (runs and ducks the incoming flack!).
[/ QUOTE ]
Why oh why do I bother getting myself angry when I read such maliciously mis-informed crap.
Why don't you refer to the "Swedish" boat that lost it's keel recently because it had smacked the bottom. Strangely enough, the same cause as the Bavaria's plight.
Before you start, yes, I have just bought a Bav and we are very happy with it.
Witness the the way Bavarias seem to have been shedding keels lately (runs and ducks the incoming flack!).
[/ QUOTE ]
Why oh why do I bother getting myself angry when I read such maliciously mis-informed crap.
Why don't you refer to the "Swedish" boat that lost it's keel recently because it had smacked the bottom. Strangely enough, the same cause as the Bavaria's plight.
Before you start, yes, I have just bought a Bav and we are very happy with it.
[3889]
...
I don't have a Bavaria but I sense a need for some "sturdy boat" owners to justify spending double the money on a boat that's no better but slower and heavier than a Bav.
sighmoon
Well-Known Member
Did boats built in the days of 'slap another layer on, just in case' used to shed their keels, or is it a modern phenomenom?
Robin
Well-Known Member
Well I saw a Westerly Centaur some 25 years ago do exactly that after going too close to Old Harry Rocks off Poole and hitting bottom. Of course being a twin keeler he carried a spare... Until they refloated her, she filled and drained with each tide. Then of course there was Simon Le Bon's 'Drum', her keel fell off at sea and they all got to sit on it upturned off Cornwall.
Have you heard the problems Moody had with skegs breaking on the older Primrose designed 36/40 footers? One sank off Australia and the owner was a bit upset I recall and had adverts in all the mags at the time collecting people for what I believe is now called a 'class action'.
Have you heard the problems Moody had with skegs breaking on the older Primrose designed 36/40 footers? One sank off Australia and the owner was a bit upset I recall and had adverts in all the mags at the time collecting people for what I believe is now called a 'class action'.
gianenrico
Well-Known Member
OLD boat osmosis
Yesterday my 17 years old boat has been lifted out of the water and the hull fully cleaned with water jet. Results: not a single blister on the Comet 303 hull. My compliments to the yard (Comar at Forlì, Italy, now defunct, as only the brand name hase survived with another company).
The boat has consistently been in the water for 50 weeks a year.
Cheers,
Gianenrico
Yesterday my 17 years old boat has been lifted out of the water and the hull fully cleaned with water jet. Results: not a single blister on the Comet 303 hull. My compliments to the yard (Comar at Forlì, Italy, now defunct, as only the brand name hase survived with another company).
The boat has consistently been in the water for 50 weeks a year.
Cheers,
Gianenrico
Swagman
Well-Known Member
I believe also that production yards are much cleaner today than say 25 years back and this has an impact.
I can recollect watching trademen stomping in and out or sticky hulls being built into a female mold - and carry into the layup paper, dirt, twigs, etc. If you've ever done it - you'll know what I mean.
This ingrained cr*p always got covered in a final interior coat so few owners would be any the wiser - but those bits would be sure to degrade in future years and create voids - which all helped propogate osmosis.
Fortunately in larger production facilities today (yes even Bavaria's) this no longer occurs - so maybe it's a contributory factor to the reduction overall?
Cheers
JOHN
I can recollect watching trademen stomping in and out or sticky hulls being built into a female mold - and carry into the layup paper, dirt, twigs, etc. If you've ever done it - you'll know what I mean.
This ingrained cr*p always got covered in a final interior coat so few owners would be any the wiser - but those bits would be sure to degrade in future years and create voids - which all helped propogate osmosis.
Fortunately in larger production facilities today (yes even Bavaria's) this no longer occurs - so maybe it's a contributory factor to the reduction overall?
Cheers
JOHN
maxi
Well-Known Member
I feel ever so justified, when the wind pipes up and the Bav that may have overtaken me earlier is now left floundering in my wake.
I also feel justified when I see, and read of, Bav problems, when at 26 years of age my sturdy boat is still sturdy, and not a single osmotic blister anywhere.
Yes, ever so justified and not a little smug !
I also feel justified when I see, and read of, Bav problems, when at 26 years of age my sturdy boat is still sturdy, and not a single osmotic blister anywhere.
Yes, ever so justified and not a little smug !
andy_wilson
Well-Known Member
Have any Bavarias ever been noted for their speed?
I thought space and value for money were the main reasons to buy one.
Horses for courses.
I thought space and value for money were the main reasons to buy one.
Horses for courses.
G
Guest
Guest
Westerly as example
Many a Bilge keeler has left a keel in the mud ...
There were a few GK's that were poor literally straight from yard ...
No its not a new problem ... but as another says - the structural issue now comes in ... drop a keel of a 70's. 80's Westerly ... get it back and re-bed after drying her out ... few rovings and glassing up - boats fine ...
Drop a keel of average boat now and you may ... I say may .... be looking at a far more serious path ... possibly a constructive loss ..
I know that my old tub .. she has water in the hull - probably a large amount ... but no blisters ..... no trouble ... and if I was to hit a new boat ......... I'm sure I know which will suffer the most ... it "aint" mine !!
Just as an example ....
Halmatic 880 of a pals ... struck a large metal buoy eastern end of solent some years ago ... this was slap bang amidships and heavily ... boat was scratched and left hull paint on buoy. We ultrasounded and checked the hull - nought wrong with her.
I was relaxing on my tub ... another helming her ... he struck a buoy outside Cowes .. He was helming not me and he had a ticket - so should have known better ... me - I was just on way out of cabin ... hull marked ... black mark still there ... but no damage ...........
Many a Bilge keeler has left a keel in the mud ...
There were a few GK's that were poor literally straight from yard ...
No its not a new problem ... but as another says - the structural issue now comes in ... drop a keel of a 70's. 80's Westerly ... get it back and re-bed after drying her out ... few rovings and glassing up - boats fine ...
Drop a keel of average boat now and you may ... I say may .... be looking at a far more serious path ... possibly a constructive loss ..
I know that my old tub .. she has water in the hull - probably a large amount ... but no blisters ..... no trouble ... and if I was to hit a new boat ......... I'm sure I know which will suffer the most ... it "aint" mine !!
Just as an example ....
Halmatic 880 of a pals ... struck a large metal buoy eastern end of solent some years ago ... this was slap bang amidships and heavily ... boat was scratched and left hull paint on buoy. We ultrasounded and checked the hull - nought wrong with her.
I was relaxing on my tub ... another helming her ... he struck a buoy outside Cowes .. He was helming not me and he had a ticket - so should have known better ... me - I was just on way out of cabin ... hull marked ... black mark still there ... but no damage ...........
Sy-Revolution
Well-Known Member
Re: Westerly as example
Just had a survey done on a Comar comet 11 (1979), no signs of osmosis or cracking.
Just had a survey done on a Comar comet 11 (1979), no signs of osmosis or cracking.
[ QUOTE ]
I feel ever so justified, when the wind pipes up and the Bav that may have overtaken me earlier is now left floundering in my wake.
[/ QUOTE ]
For someone who claims to be a surveyor you have confused and muddled perception of the pro's and con's yacht designs.
Why pick on Bavaria's to highlight the sailing characteristics of your Maxi. There are many AWB designs from the 1990' with worse hull vital statistics than a Bavaria.
[ QUOTE ]
I also feel justified when I see, and read of, Bav problems, when at 26 years of age my sturdy boat is still sturdy, and not a single osmotic blister anywhere.
Yes, ever so justified and not a little smug!
[/ QUOTE ]
If you want to talk osmosis then you should be discussing Westerly and Nicholson’s. Tarring Bavaria's with the osmosis brush is a new one on me.
Do people actually pay you for your survey reports?
I feel ever so justified, when the wind pipes up and the Bav that may have overtaken me earlier is now left floundering in my wake.
[/ QUOTE ]
For someone who claims to be a surveyor you have confused and muddled perception of the pro's and con's yacht designs.
Why pick on Bavaria's to highlight the sailing characteristics of your Maxi. There are many AWB designs from the 1990' with worse hull vital statistics than a Bavaria.
[ QUOTE ]
I also feel justified when I see, and read of, Bav problems, when at 26 years of age my sturdy boat is still sturdy, and not a single osmotic blister anywhere.
Yes, ever so justified and not a little smug!
[/ QUOTE ]
If you want to talk osmosis then you should be discussing Westerly and Nicholson’s. Tarring Bavaria's with the osmosis brush is a new one on me.
Do people actually pay you for your survey reports?
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