Osmosis - Not a concern?!?
- Thread starter Dazzajohm
- Start date
Seastoke
Well-Known Member
Two things ask insurers about surveyors report and if it is out the water get a quote for osmosis treatment then put it to seller
kashurst
Well-Known Member
I wouldn’t be concerned by those two lumps. Easy to sort next time the boat is ashore.
I bought a boat many years ago with a few similar lumps reported by surveyor. Sold boat 6 years later next surveyor said no sign of osmosis at all
I bought a boat many years ago with a few similar lumps reported by surveyor. Sold boat 6 years later next surveyor said no sign of osmosis at all
Dazzajohm
N/A
Thanks for all the comments. The general consensus on here seems fairly positive so I guess what I've previously believed on this topic is not necessarily true. I'm also wondering if when the boat was previously treated with epoxy it wasn't the whole hull, just where there were previous blisters which if that the case I might consider doing the whole hull myself. First things first I want to see the full written report which should be with me early next week and provide more in depth detail and then I can make a final decision 
PowerYachtBlog
Well-Known Member
To me those hardly look like osmotic blisters. Was acid water pouring out of those blisters or it was just gel coat chipping?
Dazzajohm
N/A
I’m still awaiting the full report but the surveyor said that apparently the smell of vinegar was indicative of osmosis blisters and there was the smell of vinegar.
MapisM
Well-Known Member
How "deep" are those cavities?
I'm not sure if there's any scientific criteria to draw a line, but I've always heard of "blistering" as referred to something VERY superficial, with bubbles growing between the gelcoat and the first GRP layer, with very little acetic smell and GRP aggression, if any at all.
This is what I assumed in my first reply above, but as far as can be told from your pic, that hole looks very different - as if the chemical degradation would have started from the inner GRP layers.
And if that would be the case, while obviously repairing just a couple of tiny points remains easy peasy, my concern would be that there's no logical reason why the same effect shouldn't be growing subtly also inside many other areas of the hull... :ambivalence:
I hate to come across as scaremongering, but that's the way I see it.
Only based on a not very detailed pic, mind. I might well be totally wrong - and it wouldn't be the first time!
Elessar
Well-Known Member
That is not true. An epoxy blister will not smell of vinegar.
Dazzajohm
N/A
How "deep" are those cavities?
I'm not sure if there's any scientific criteria to draw a line, but I've always heard of "blistering" as referred to something VERY superficial, with bubbles growing between the gelcoat and the first GRP layer, with very little acetic smell and GRP aggression, if any at all.
This is what I assumed in my first reply above, but as far as can be told from your pic, that hole looks very different - as if the chemical degradation would have started from the inner GRP layers.
And if that would be the case, while obviously repairing just a couple of tiny points remains easy peasy, my concern would be that there's no logical reason why the same effect shouldn't be growing subtly also inside many other areas of the hull... :ambivalence:
I hate to come across as scaremongering, but that's the way I see it.
Only based on a not very detailed pic, mind. I might well be totally wrong - and it wouldn't be the first time!
As I understood, the blisters were very shallow and when moisture readings were taken they were not higher than they should be so I wouldn't expect there to be underlying issues of more blisters as surely the moisture readings would indicate this? Again I guess I'll know more when the full report arrives
Sailorsam101
Well-Known Member
Just remember one thing...no boat has ever sunk because of Osmosis bubbles!
As said earlier easily fixed and when afloat you won't even know they are there. Again as said earlier very unusual for Fairline hulls of that age to have bubbles..i have basically the same 1991 hull and not a blemish ever.
As said earlier easily fixed and when afloat you won't even know they are there. Again as said earlier very unusual for Fairline hulls of that age to have bubbles..i have basically the same 1991 hull and not a blemish ever.
Dazzajohm
N/A
By way of an update, I received the full report which basically says the boat was a fair example for its age. Did have a few recommendations but all relatively simple to fix. In the end, the surveyor found 12 blisters of no more than 10mm in diameter and no more than 0.5mm deep. The moisture content of the hull was high but states that some of this would obviously be due to the fact the boat had just been lifted and held in slings for the survey. So with this in mind I've gone back with a lower offer to take in to account treatment at a later date. See what they come back with.
MapisM
Well-Known Member
Mmm... Makes me wonder whether it made sense to make humidity measurements at all, with the hull still dripping water.
That aside, out of idle curiosity, do you possibly have an enlarged photo of the circled spot visible in your post #10?
As far as could be told by that pic, I would have sworn that it's MUCH deeper than 0.5mm, which essentially is still at the level of gelcoat layer.
Assassin
Well-Known Member
Simple solution, get a specialist repairer with a good reputation to examine the hull and give you a quotation for the work to repair it correctly.
Bigplumbs
Well-Known Member
You do realise this is a 27 year old boat we are talking about. Do you expect brand new condition !
Dazzajohm
N/A
Mmm... Makes me wonder whether it made sense to make humidity measurements at all, with the hull still dripping water.
That aside, out of idle curiosity, do you possibly have an enlarged photo of the circled spot visible in your post #10?
As far as could be told by that pic, I would have sworn that it's MUCH deeper than 0.5mm, which essentially is still at the level of gelcoat layer.
No, I thought the same, it almost seemed pointless taking the moisture readings. I've tried to attach an enlarged photo.
Dazzajohm
N/A
No I quite agree, but I just need to make sure I can get the boat at a sensible price as almost certainly when the time comes for me to sell I will have some difficulty plus I also need to consider that I may need to get the hull treated at some point depending on how long I keep the boat for
MapisM
Well-Known Member
I'm afraid it isn't much better than the previous one, but fwiw (and as far as I can see) that spot doesn't look like the typical gelcoat blistering to me.
Since you saw the hull it in flesh, I'm attaching a closeup pic of gelcoat blistering which you might find useful as a reference.
The following pic was taken after the removal (through sandblasting) of a gelcoat bubble, which didn't reveal any chemical degradation of the GRP underneath, which was totally unaffected and completely dry.
For size reference, the bubble diameter is about 8mm.
kashurst
Well-Known Member
good call, I still wouldn't be concerned by the potentially high moisture readings or a few possibly osmotic blisters. Moisture content reading is fraught with difficulties (especially in the UK) and ambiguity. If you get a few £ knocked off and buy the boat, just put the boat ashore over the winter for a few winters and let the wind dry it out a bit. What are the engines like?
Dazzajohm
N/A
According to the surveyor, he was happy with the engines, oil was checked in both engine and gearbox and found to be good as well
volvopaul
Well-Known Member
Did he take oil samples from both engine and gearbox ?
