Blisters! Is it Osmosis?

[sabray]

Originally Posted by MacG

Meanwhile there are (solid) fiberglass boats aged 50 years and still in good condition.
Worse are the sandwich/balsa constructions from the 70's. Some Bowmans 45/6 are already hammered down with hefty restaurations. Same for some Swedish production boats from that era. Sandwich constructions in combination with FRP are sooner or later bound to delaminate. Do not forget that material does not last forever. Every material save for titanium has its final date written allover.

Because the old guys have tons of resin to disolve and thick ass hulls plus many lams. No blisters but the outer laminates have no resin. loose the resin from 6 lams or 26 I would take 26 any day.. your right cored hulls with high efficiency resin ratios have a higher risk to structural resin loss. Polyester disolves figure out if it is a degeneration that works for you and your boat.

[Siren o the Sea]

Definitions:

Noun1.hydrolysis - a chemical reaction in which water reacts with a compound to produce other compounds; involves the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion from the water
Noun1.osmosis - (biology, chemistry) diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

[Tomtom39]

Originally Posted by sepeteus

Very interesting the fact that you found same defects on your girl. I would be keen to see some pictures of yours to see myself! Look, I am totally in peace with my so called 'disaster' on our 47.7. I simply groung back and washed with soapie water + acetone and fiberglassed the lost surface. Before installed new seacocks, reinforced the fiberglass with marine ply blocks inside. As you asked, was the repairs successful, the time will tell. I will find out the next time on slips. Good luck with your First 47.7. It is an awesome sailing boat!

Thanks for the update. I will post some pix but they are identical to the ones that you have posted previously and really amazed me when I saw them!
The guy that does all my work on my boat has suggested replacing all the sea cocks at the same time as the moisture readings are very high around this area so he thinks we have water ingress between the skin fitting and the hull. I actually thought doing what you suggested was the best and then just monitoring, but he wants to solve the potential problem. Seems like some bad workmanship at beneteau.
Keep in touch
Agreed awesome boat. We have the teak decks so a little heavier but very fast cruiser!!!!
Nick

[Tomtom39]

Just an update on my blisters around my seacocks
It now appears that from many specialists looking at the issues!! They have advised that the moisture ingress is getting through from the outside and is down to the fact that beneteau put the seacocks in the hull with the mould when the boat is built, hence the through hole for the seacock is not sealed.
We have flush seacocks and the gel coat ends at the edge of the through fitting and this is where the moisture is entering.
So all seacocks now being taken out and replaced. Grinding back gel coat to the substrate and then let it dry! Re seal through hole prior to fitting new sea cocks. Big job but now will have new certified sea cocks and moisture should be solved.
Interesting beneteau were quite open about the problem.
All fun and games
Nick

[Seahunter]

Originally Posted by Tomtom39

Just an update on my blisters around my seacocks
It now appears that from many specialists looking at the issues!!
So all seacocks now being taken out and replaced. Grinding back gel coat to the substrate and then let it dry! Re seal through hole prior to fitting new sea cocks. Big job but now will have new certified sea cocks and moisture should be solved.

This is good, but old news. Check the Beneteau and Jenneau owner's site. I have had 3 friends, plus an acquaintance that've had all their through hulls replaced because of the same issues on boats less than 2 years old. B~ blamed the issue on faulty resin (and have sued the supplier)? They've all been bonded (electrically) now and have bronze fittings. Although B and J haven't given a complete answer one boatyard says there was a reaction between the resin and the marelon fittings?
Here's a post from an alternate site:

"Re: What are Jeanneau seacocks made from?
Post by dublin on Jul 22, 2011, 11:03am
I con(T)acted jeanneau by email and they told me to take it up with the agent. The agent said to take some photos. I sent them the photos by email last Monday and received an email yesterday from the agent telling me that jeanneau had agreed to supply replacement seacock and the agent would fit it free of charge when the boat is next hauled for scrubbing. The boat is 4 years old."

I actually viewed the fittings on my friend Peter's 2 year old boat and they were all discolored pinkish green and soft. They hauled the boat the next day and B~ responded with a no way we're fixing the problem. His lawyer called B~ that afternoon and it took them 15 minutes to call Peter and tell him to take some pics and email them back. A week later they called the yard and okay'd the repairs. The bill was close to 25 G notes. I guess they have insurance.

[MarkSF]

Wow, I don't feel so bad about replacing 3 seacocks on my 28 year old Bristol. They are just worn out though, no leakage issues except for what leaks out around the worn shaft.

[s/v Jedi]

Originally Posted by Seahunter

The bill was close to 25 G notes. I guess they have insurance.

Hold on a sec, how much was the bill and in which currency?

cheers,
Nick.

[Seahunter]

Originally Posted by s/v Jedi

Hold on a sec, how much was the bill and in which currency?

$25,000 US. The work was done at the "Boat Yard" in Marina Del Rey. The work included; replacing ALL through hulls with bronze fittings (with backing plates), a full sanding of the bottom for inspection, and the (electrical) bonding of all through hull mechanical fittings to a divers plate, and new bottom paint. Pretty cheap I say.

[s/v Jedi]

Originally Posted by Seahunter

$25,000 US. The work was done at the "Boat Yard" in Marina Del Rey. The work included; replacing ALL through hulls with bronze fittings (with backing plates), a full sanding of the bottom for inspection, and the (electrical) bonding of all through hull mechanical fittings to a divers plate, and new bottom paint. Pretty cheap I say.

What?! cheap? If this is cheap for Marina del Rey then I don't want to know about expensive! This would cost well under $5k for my boat incl. haul-out here.

cheers,
Nick.

[3 Sheets]

Originally Posted by boatpoker

Try contacting an Interlux rep and asking for a guarantee. When he stops laughing, he'll tell you No Way !

This quote just about sums it up for me. Here's a picture of my keel. The rest of the hull looks the same. The blisters are dry and don't smell. The boat is 32 years old. I plan on painting right over them and seeing if they have increased in size at the next haul out.

[s/v Jedi]

Originally Posted by 3 Sheets

This quote just about sums it up for me. Here's a picture of my keel. The rest of the hull looks the same. The blisters are dry and don't smell. The boat is 32 years old. I plan on painting right over them and seeing if they have increased in size at the next haul out.

I unfortunately saw about 700 of those blisters recently and while grinding them all out, they surely had the vinegar smelling substance inside. How do you know these are dry? They can't form dry, there must be liquid in there...

What do you expect to gain with waiting to correct things? If they stay the same size, you still have to do the job and if they have grown, the job became bigger...

ciao!
Nick.

[3 Sheets]

First things first: I'm no expert! but I did do some research and found a lot of conflicting opinions on the subject. When I googled boat blisters the first website that pops up (yachtsurvey.com) has a lot of info there on the subject. My blisters aren't being caused by a through hull like the OP's, in which case I would correct that issue. The previous owner of my boat showed me pictures of the boats blisters when he bought it ten years ago and when he hauled it for paint, and said they hadn't changed in size or quantity, he also mentioned that they were dry. When i had the boat surveyed we cracked a few open with a knife and they were dry, I don't know if that means anything good or bad, obviously the blisters were caused by water saturation in the mat. I am of the opinion right now that after 32 years what has already happened is the extent of what will happen. Without the presence of large blisters or deformation I plan on doing nothing about them. I will paint the bottom and at next haul out see if things look the same. What I am an expert on is how much beer I can buy with my savings.

Cheers,
Mike

[mitiempo]

Here's an interesting article on blisters from Jan de Groot, a very experienced surveyor that makes interesting reading.
Sea Lake Yacht Sales (Kemah, TX)

[Tomtom39]

Hi all,

Just a quick update on what I have found now that I have removed my through hull fittings and ground back the gel coat on my beneteau 47.7 where small blisters were present!!

It appears that in beneteaus wisdom they used filler around the seacocks, presumable this was done when they removed the mould and some of the laminate was pitted.
I have ground this all back and will now start to relay the glass.
What was interesting was the moisture readings were so high before the work and after grinding the gel away the filler was so high. now the filler has gone moisture reading are very low so all good.
Thought the post would assist anyone that has any blistering around seacocks! Seems to be the filler

Thanks nick

[sepeteus]

Good news Nick! I am certainly glad to get some closure for this story. As we all know who followed this thred, there was some experts who jumped into conclusions with not much knowledge or far too much knowledge. Its kind of funny how people complicate things taking 'know it all attitude' instead trying to solve it as a puzzle together with the wealth of knowledge of the members of this forum. Nick, thank you so much for the last piece to complete this! I certainly felt lost with my 'osmosis' problem.