Is It Necessary to Haul Out Each Year To Let the Boat "Dry Out"

[boatpoker]

Originally Posted by Kenomac

I happen to know that Polux is out cruising and probably in an anchorage, his internet isn't 100% like those of you sitting in your house.

Allow some time.

ok, will allow some time but I really don't expect an (reasonable) answer.

PS. In the early 70's I did some work for Consumers Glass in Toronto and witnessed hygrometric testing of bottles for Coca Cola. The test involved a laboratory with extremely high pressure equipment surrounded with armor plated glass. If Polux knows of a pocket size unit that a surveyor can carry, I'd love to see it

PS. I am despondently in a house for the next couple of months after an 11 month cruise and will be back to cruising in just a few painful more months.

[noelex 77]

Originally Posted by Kenomac

Thanks. Going to scuba dive under the boat to service the anodes and dust it off next week. It's the first time it was wintered in fresh water. I can hear that the prop anode is a little loose.

Ken if you are going to be spending winter in fresh water dont forget that zinc anodes are not a good choice.

[Sailmonkey]

Originally Posted by noelex 77

Ken if you are going to be spending winter in fresh water dont forget that zinc anodes are not a good choice.

Yep, magnesium is the anode of choice for fresh.

We use aluminum at home, the marina and most of the bay are brackish.

[Polux]

Originally Posted by Sailmonkey

I'm not sure I would want a "high quality" modern boat that could not survive year round immersion in its natural habitat.

They survive alright. It will have only a bigger content of moister on the hull than a boat that is dried up every year. It can not be a problem but a higher moisture content on fiberglass it is not a thing good on a fiberglass boat at a long therm. That is why new boats come with several layers of a epoxy paint on the bottom when they are new.

That paint loses efficacy in around 5 years, so if you want to keep it on the water in pristine condition all you have to do is to put back some new epoxy layers each 5 years.

[Polux]

Originally Posted by boatpoker

Please provide a link that shows one of these "highly professional very expensive devices" that your surveyor used.

Look, if you don't know that a good professional surveyor with good equipment can do comprehensible moisture readings on a hull than it is pretty useless to continue to talk about this.

In fact this particular surveyor is linked to research in what regards new ways to have even better information than the one that is available with a good device to read moisture (that was what he used successfully to detect a high level of moisture on a boat that I was interested in, that in fact had it).

He is doing experiments with very expensive material that come from medical sources adapted to boat surveying and he can see much more than moisture on a hull. Some years back when my boat was rammed he got some images from the hull, kind of RX images where you could see it all, the core, the outer layers, if there had been some delamination, if there was some moisture on the sandwich. Pretty impressive, I saw the images. The insurance company paid. It was cheaper than to physically verify it there was a problem.

He has patents and is talking with a company to make it available commercially but it turns out the interest is not enough, it is expensive and most surveyors prefer to knock on the hull as way to get information.

[Polux]

Originally Posted by Kenomac

I happen to know that Polux is out cruising and probably in an anchorage, his internet isn't 100% like those of you sitting in your house.

Allow some time.

Also when i am cruising boat forums are far from being my main interest

I post only when my wife wants to stay on a place more than a day and I got bored even if the place is nice. I am here for (2 days), lovely place.

Tomorrow I will sail away, no time for boat forums then

[boatpoker]

Originally Posted by Polux

Look, if you don't know that a good professional surveyor with good equipment can do comprehensible moisture readings on a hull than it is pretty useless to continue to talk about this.

In fact this particular surveyor is linked to research in what regards new ways to have even better information than the one that is available with a good device to read moisture (that was what he used successfully to detect a high level of moisture on a boat that I was interested in, that in fact had it).

He is doing experiments with very expensive material that come from medical sources adapted to boat surveying and he can see much more than moisture on a hull. Some years back when my boat was rammed he got some images from the hull, kind of RX images where you could see it all, the core, the outer layers, if there had been some delamination, if there was some moisture on the sandwich. Pretty impressive, I saw the images. The insurance company paid. It was cheaper than to physically verify it there was a problem.

He has patents and is talking with a company to make it available commercially but it turns out the interest is not enough, it is expensive and most surveyors prefer to knock on the hull as way to get information.

So now you are talking "moisture measurements" where previously you were meandering on about "hydroscopic testing" .... nice switch. So I suppose you can't provide information on this moisture measuring hygroscopic tester because it is secret !

You clearly have no idea of what you speak and do a disservice to all who come here looking for real information by continually spreading this fantasy.

[Xlantic]

David Pascoe has written several authoritative articles on osmosis and blistering. Googling "David Pascoe" and "osmosis" will reveal many.

Here is one that debunks drying out boats:
Boat Hull Blisters : My Wet Hull Won't Dry - by David Pascoe, Marine Surveyor

Here is one where he debunks moisture meters:
Buying a Boat or Yacht : Buying a Blister Boat

More here:
Hull Blisters on Boats and Yachts - by David Pascoe, Marine Surveyor

[boatpoker]

Originally Posted by Xlantic

David Pascoe has written several authoritative articles on osmosis and blistering. Googling "David Pascoe" and "osmosis" will reveal many.


Here is one where he debunks moisture meters:
Buying a Boat or Yacht : Buying a Blister Boat

Somewhat similar to my Moisture Meter Mythology although My testing and that of Professional Boat Builders Magazine have proven him wrong in some respects. Particularly about depth of reading. While I have never found a meter that reads as deep as the manufacturer claims, my test panels and photographs in my article clearly show that they do read more than just "surface moisture" as Pascoe claims.

I also have a few comments on Thermal imaging in that article which I suspect Polux may be mistakenly referring to.

[Kenomac]

Originally Posted by noelex 77

Ken if you are going to be spending winter in fresh water dont forget that zinc anodes are not a good choice.

I'm new to sweet water, what's the best choice for brackish water? The boat stays in brackish water for six months, then six months in salt water.

Why the difference? Conductivity? Does it cause an issue using zinc for the six months, or does it just eat away at it faster?

[boatpoker]

Originally Posted by Kenomac

I'm new to sweet water, what's the best choice for brackish water? The boat stays in brackish water for six months, then six months in salt water.

Why the difference? Conductivity? Does it cause an issue using zinc for the six months, or does it just eat away at it faster?

Aluminum indium is your best choice for that.

[Polux]

Originally Posted by boatpoker

So now you are talking "moisture measurements" where previously you were meandering on about "hydroscopic testing" .... nice switch. ......

You now, it is not alright to quote somebody in something one has not said and it says something about you as a person:

I never talked or referred "hydroscopic testing"
nas you say I did. I talked about "Hygrometric Test" and explained what I mean with it, at your request: "A calculation of the moisture content on the hull through a reliable device and a skilled operator (a very experienced surveyor)."

Obviously the term hydroscopic is badly used since ir refers to moisture on the air but the explanation leaves no doubts about what I meant. Blame it on my bad English the fact that I had not applied the right word, even if I explained clearly what I was talking about and that has been always about the same thing: measuring the content of moisture on a composite.

Originally Posted by boatpoker

You clearly have no idea of what you speak and do a disservice to all who come here looking for real information by continually spreading this fantasy.

It is you that don't know what you are talking about when you quote wrongly other posters trying to diminish their contribution with false statements. Not nice!!!!

[Stakaman]

Polux actually you aren't wrong about how you use the words hygrometric and hydroscopic ..
The words roots are from Greek language (hygrometric = υγρό μέτρηση /μέτρηση της υγρασίας and hydroscopic = υδροσκοπηση )
Actually in your "bad English" (my English are also bad)you have used the right word for measure moister which is hygrometric "(μέτρηση της υγρασίας )
All thought I have understand what you meant I am not sure for the result and the way and conditions it must performed to deliver exact measurements.

[noelex 77]

Originally Posted by Kenomac

I'm new to sweet water, what's the best choice for brackish water? The boat stays in brackish water for six months, then six months in salt water.

Why the difference? Conductivity? Does it cause an issue using zinc for the six months, or does it just eat away at it faster?

Originally Posted by boatpoker

Aluminum indium is your best choice for that.

Yes, Boatpoker is correct. For this sort of application aluminium anodes are the best choice. Unfortunately, you really need to change them all.

The problem with zinc anodes in fresh water is that they develop a coating that acts as an insulator and stops them working. If you go back to salt water the coating tends to remain. You can sand and scrape the anodes exposing the uncoated zinc and get them back to working correctly in salt but if you go back to fresh water it will reform. It is not possile to keep zinc anodes working in fresh water the coating forms reasonably quickly, although the need for anodes is less in fresh water.

Aluminium is ideal for salt and brackish water and is acceptable for fresh (magnesium is ideal).

[boatpoker]

Originally Posted by Polux

It is you that don't know what you are talking about when you quote wrongly other posters trying to diminish their contribution with false statements. Not nice!!!!

Still waiting to here what that magical piece of secret equipment is