G
Guest
Guest
Re: Brendan ... I respect your posts but ....
Byeee ...
Byeee ...
Hull Moisture?????????
- Thread starter swanny
- Start date
G
Guest
Guest
Sorry ...
So the profession I have been conducting and also owning companys in - is not Professional or correct ...
Proper Marine Surveyor Eh ??? And what makes that then ??
Had to get that one in ... !!
/forums/images/graemlins/tongue.gif
So the profession I have been conducting and also owning companys in - is not Professional or correct ...
Proper Marine Surveyor Eh ??? And what makes that then ??
Had to get that one in ... !!
/forums/images/graemlins/tongue.gif
G
Guest
Guest
article ...
This article has been doing the rounds for many a moon and it leads to various discussions ...
Points such as : Metering inside hull ...... which meter is he actually referring to ? ..... different moulding techniques etc. across the atlantic etc.
These are only a small part of the discussions that can start from this sort of article. I do not argue with his writings - but advise caution - as I believe he does not cover enough of some parts and overdoes others.
I have for years followed the principle of learning while working ... we never see all situations and many new ones come up ... I started really learning more when I got my Tramex and explored so much more than the old Soveriegn and Protimeters allowed. I communicated with Nigel Clegg ... a veritable expert on this and as far as I am concerned leaves most others well behind.
Having witnessed some strange and unexpected - I am always on the look out and exploring for more ...
I have been involved with Boats having been peeled and the re-floated to sail to treatment centre - no ill effects ...
Have seen boats fail to dry-out with peeling ...
Have seen an operator with balsting get over-enthusiastic on one spot ...
Etc. etc.
We are all learning and this article should only be used as a guide to learn more. UK Universities have done countless studies into this subject and all have come up with various details - not all agreeing.
The meter is a good tool - but like a GPS / Radar etc. - it is an aid and the operators interpretation can be crucial.
This article has been doing the rounds for many a moon and it leads to various discussions ...
Points such as : Metering inside hull ...... which meter is he actually referring to ? ..... different moulding techniques etc. across the atlantic etc.
These are only a small part of the discussions that can start from this sort of article. I do not argue with his writings - but advise caution - as I believe he does not cover enough of some parts and overdoes others.
I have for years followed the principle of learning while working ... we never see all situations and many new ones come up ... I started really learning more when I got my Tramex and explored so much more than the old Soveriegn and Protimeters allowed. I communicated with Nigel Clegg ... a veritable expert on this and as far as I am concerned leaves most others well behind.
Having witnessed some strange and unexpected - I am always on the look out and exploring for more ...
I have been involved with Boats having been peeled and the re-floated to sail to treatment centre - no ill effects ...
Have seen boats fail to dry-out with peeling ...
Have seen an operator with balsting get over-enthusiastic on one spot ...
Etc. etc.
We are all learning and this article should only be used as a guide to learn more. UK Universities have done countless studies into this subject and all have come up with various details - not all agreeing.
The meter is a good tool - but like a GPS / Radar etc. - it is an aid and the operators interpretation can be crucial.
swanny
Well-Known Member
Take it easy guys!.....is this all for me? I have never had so much attention. I must tell Cocoro what is happening online as a result of her aging rump! As you can imagine, it's difficult for a layman like me to make much sense of the above but I do appreciate your efforts. I will get hold of a moisture meter, and see what I find. I hesitate to say that a surveyor told me that he always expects to find at least 12% moisture in any hull that spends half the year in water. I know though that to epoxy the hull needs much less than this, as little as 3%. So, perhaps I will keep you posted. I would be happy to here any more comments or help through email or message on this site. I am amazed at what I don't know. Thanks
Juggler7823
Well-Known Member
Re: Sorry ...
What does make a "proper marine surveyor"?
What does make a "proper marine surveyor"?
mikebees
Well-Known Member
Avoiding Osmosis(?) & Apologies to Nigel
Apologies if needed, no disrespect to you intended. I was thinking of the endless postings and opinions on osmosis from evey Tom, Dick and Harry I have seen on these forums with never any definite conclusion at the end of it all. I was not aware you were a yacht Surveyor.
May I weigh in with my own practical and probably controversial advice as to how not to aquire a boat with osmosis? In the mid 1980s iso-resins became available as a replacement for ortho-resins. I was told by a friend who was a Director of one of the biggest and probably the best UK moulding companies that iso-resin boats were almost immune to osmosis but ortho-resin hulls were trouble. What amazed me was that he went on to tell me that some UK boatbuilders who subcontracted hull mouding to his company inisted on them still using ortho resins to keep costs down.
The lessons are: buy a boat built after 1985 and make sure iso-resins were used - but don't ask me how!
Apologies if needed, no disrespect to you intended. I was thinking of the endless postings and opinions on osmosis from evey Tom, Dick and Harry I have seen on these forums with never any definite conclusion at the end of it all. I was not aware you were a yacht Surveyor.
May I weigh in with my own practical and probably controversial advice as to how not to aquire a boat with osmosis? In the mid 1980s iso-resins became available as a replacement for ortho-resins. I was told by a friend who was a Director of one of the biggest and probably the best UK moulding companies that iso-resin boats were almost immune to osmosis but ortho-resin hulls were trouble. What amazed me was that he went on to tell me that some UK boatbuilders who subcontracted hull mouding to his company inisted on them still using ortho resins to keep costs down.
The lessons are: buy a boat built after 1985 and make sure iso-resins were used - but don't ask me how!
G
Guest
Guest
What makes a Proper Marine Surveyor ?
Depends on the Country and line of Work undertaken ...
There are Professional Bodies but very few Yacht Surveyors would even get close to being accepted - as they require serious Naval Arch. backgrounds, Marine Engineering etc.
There are the "Private" self appointed bodies - such as YDSA, otherwise known as YBDSA, YSA etc. etc depending on how much they want to say ... Also IMSA .... etc.
Our criteria for our work and we cover from a stick in the water up to the biggest ships in the world as well as cargoes etc. etc. - is background, experience and aptitude to learn and learn and learn ... Qualifications - in the field here discussed - Yachts - I am sure that someone will come up with a College, Institute, Uni course or whatever ... very good - but is not an Industry standard or requirement.... in fact any tom dick or harry can set-up. (We are talking UK here )
I was accepted by Saudi Govt as a Marine Surveyor as well as Latvian / Russian etc. I was "ticketed" as such ... so in effect am qualified.
The basis of some of the well known "bodies" who remember hold no Formal Charter or Authority of Govt etc. to oversee this field - is to check over past and future reports made by members .. It is claimed that they have Qualified Surveyors ... by whom and by what standard ? In-house of course. And of course that In-house is self-regulated and not subject to outside scrutiny.
Sorry to be a b.....d about this - but I get a bit uptight with so-called "Qualified" Surveyors claing Professional Qualified when in fact it is not strictly true.
I have personal experience of a YBDSA guy writing a report that in all honesty - wasn't worth the paper it was written on and I had to pull him apart to get the Insurnace Co. to understand ...
I am not at present a member of any of the associations or institutes - I stay independent - no dictates on how I construct my fee's, no stupid inane rules etc. that protect them - not you or me ... etc. etc.
I would like to put together a True Independent Marine Survey Group Membership .. but the work involved would probably be too much for me on my own ... so it is left undone ...
So the libel writs will fall from heaven now ... what a life eh !!
Depends on the Country and line of Work undertaken ...
There are Professional Bodies but very few Yacht Surveyors would even get close to being accepted - as they require serious Naval Arch. backgrounds, Marine Engineering etc.
There are the "Private" self appointed bodies - such as YDSA, otherwise known as YBDSA, YSA etc. etc depending on how much they want to say ... Also IMSA .... etc.
Our criteria for our work and we cover from a stick in the water up to the biggest ships in the world as well as cargoes etc. etc. - is background, experience and aptitude to learn and learn and learn ... Qualifications - in the field here discussed - Yachts - I am sure that someone will come up with a College, Institute, Uni course or whatever ... very good - but is not an Industry standard or requirement.... in fact any tom dick or harry can set-up. (We are talking UK here )
I was accepted by Saudi Govt as a Marine Surveyor as well as Latvian / Russian etc. I was "ticketed" as such ... so in effect am qualified.
The basis of some of the well known "bodies" who remember hold no Formal Charter or Authority of Govt etc. to oversee this field - is to check over past and future reports made by members .. It is claimed that they have Qualified Surveyors ... by whom and by what standard ? In-house of course. And of course that In-house is self-regulated and not subject to outside scrutiny.
Sorry to be a b.....d about this - but I get a bit uptight with so-called "Qualified" Surveyors claing Professional Qualified when in fact it is not strictly true.
I have personal experience of a YBDSA guy writing a report that in all honesty - wasn't worth the paper it was written on and I had to pull him apart to get the Insurnace Co. to understand ...
I am not at present a member of any of the associations or institutes - I stay independent - no dictates on how I construct my fee's, no stupid inane rules etc. that protect them - not you or me ... etc. etc.
I would like to put together a True Independent Marine Survey Group Membership .. but the work involved would probably be too much for me on my own ... so it is left undone ...
So the libel writs will fall from heaven now ... what a life eh !!
G
Guest
Guest
Swanny .... no problem ...
You are fair and square ...
You just happen to hit on a subject that gets expert ?, amateur and all-sorts replies ...
I for one am not expert on it and forbid me saying I am ... I just have the awful job of looking at hulls etc. with it ...
The beauty of the forums is the ability to get a varied answers and then to sift through to reach what you want to hear ... asin all threads - a lot of words get posted ... the real meat is often in just a few ...
Don't worry - we old goats on here are used to biting each other !!
You are fair and square ...
You just happen to hit on a subject that gets expert ?, amateur and all-sorts replies ...
I for one am not expert on it and forbid me saying I am ... I just have the awful job of looking at hulls etc. with it ...
The beauty of the forums is the ability to get a varied answers and then to sift through to reach what you want to hear ... asin all threads - a lot of words get posted ... the real meat is often in just a few ...
Don't worry - we old goats on here are used to biting each other !!
Juggler7823
Well-Known Member
High moisture readings, blister formation and hull strength
Marine surveyors (of all types) are expected to give their views on the condition of the hulls that they are surveying. I would like to know the basis of the claims that they make. What is the scientific and technical evidence for the relationship between high moisture readings, blister formation and degraded hull strength?
Before anyone asks, none of my boats have ever been surveyed and declared to have osmosis!
Marine surveyors (of all types) are expected to give their views on the condition of the hulls that they are surveying. I would like to know the basis of the claims that they make. What is the scientific and technical evidence for the relationship between high moisture readings, blister formation and degraded hull strength?
Before anyone asks, none of my boats have ever been surveyed and declared to have osmosis!
ex-Gladys
Well-Known Member
Re: High moisture readings, blister formation and hull strength
Expert -
Derivation: ex as in "has been" ;spurt as in "drip under pressure"
Expert -
Derivation: ex as in "has been" ;spurt as in "drip under pressure"
G
Guest
Guest
Recc\'d reading :
The Osmosis Myth Exploded Pt1 + 2 by Nigel Clegg.
Unlike some manuals / publications this sticks strictly to the subject without wandering off into other areas. I recc'd this manual as it is about the best I know ... takes you from early moisture ingress - how it gets in, why it cannot get out and why Blisters form etc.
I will not try to answer on a post the question - as a) the forum would not like a hundred pages of dreary tripe from me and b) I would probably leave out something in the compressing to forum post.
It is a subject that is not simple and the question may be straightforward, but the answer is not - also subject to who is answering ! Not all Surveyors agree .... generally yes, specifically some points no.
The Osmosis Myth Exploded Pt1 + 2 by Nigel Clegg.
Unlike some manuals / publications this sticks strictly to the subject without wandering off into other areas. I recc'd this manual as it is about the best I know ... takes you from early moisture ingress - how it gets in, why it cannot get out and why Blisters form etc.
I will not try to answer on a post the question - as a) the forum would not like a hundred pages of dreary tripe from me and b) I would probably leave out something in the compressing to forum post.
It is a subject that is not simple and the question may be straightforward, but the answer is not - also subject to who is answering ! Not all Surveyors agree .... generally yes, specifically some points no.
Birdseye
Well-Known Member
[ QUOTE ]
Take it easy guys!.....is this all for me? I have never had so much attention. I must tell Cocoro what is happening online as a result of her aging rump! As you can imagine, it's difficult for a layman like me to make much sense of the above but I do appreciate your efforts. I will get hold of a moisture meter, and see what I find. I hesitate to say that a surveyor told me that he always expects to find at least 12% moisture in any hull that spends half the year in water. I know though that to epoxy the hull needs much less than this, as little as 3%. So, perhaps I will keep you posted. I would be happy to here any more comments or help through email or message on this site. I am amazed at what I don't know. Thanks
[/ QUOTE ]
There might be a lot of "handbags" and offended dignity about, but there's also been a fair bit of good advice.
I've not seen any science that gives a precise moisture meter threshold level at which you can epoxy a grp hull, but the figure normally quoted is 5 or less on the Sovereign, and insofar as you can relate the two meters this corresponds to about 12 on scale 2 of the Tramex. What happens if you are a few points above this level, I do not know.
Its sense to use a meter - the cost of epoxy is high, not to mention the labour in cleaning off a hull . Ships and haporth of tar etc!. You can hire a meter for about £40 - pm me if you want details. And Stephenh's commendably scientific approach is an excellent way of using one.
Heating to dry off is not really a good idea - except that it allows a commercial yard to get your boat through quicker! The reason its not good is that all you are doing is drying out a hygroscopic solution inside the laminate but leaving it there. When the heat is removed , this now more concentrated solution will immediately start trying to suck moisture back in and epoxy is still permiable to water. Less so that poly, but still premiable. Plus you have an inside surface of poly to let moisture in too.
So what you need to do is to remove these hygroscopic salts as much as possible. You do this by frequent washing of the laminate surface with fresh water once you have got rid of the gelcoat. Once all the hygroscopic salts etc have gone, the laminate then dries to an acceptable levelk very quickly.
One thing worth mentioning about meters. I found that you could easily detect dampness on the inner surface of a laminate from the outside of a hull even using Sovereign. Admittedly the laminate concerned was maybe 6mm, but it does mean that when you find spot high readings with a meter you first need to look inside to see if there is a reason. Dont just jump to the conclusion thatb the laminate is wet.
Take it easy guys!.....is this all for me? I have never had so much attention. I must tell Cocoro what is happening online as a result of her aging rump! As you can imagine, it's difficult for a layman like me to make much sense of the above but I do appreciate your efforts. I will get hold of a moisture meter, and see what I find. I hesitate to say that a surveyor told me that he always expects to find at least 12% moisture in any hull that spends half the year in water. I know though that to epoxy the hull needs much less than this, as little as 3%. So, perhaps I will keep you posted. I would be happy to here any more comments or help through email or message on this site. I am amazed at what I don't know. Thanks
[/ QUOTE ]
There might be a lot of "handbags" and offended dignity about, but there's also been a fair bit of good advice.
I've not seen any science that gives a precise moisture meter threshold level at which you can epoxy a grp hull, but the figure normally quoted is 5 or less on the Sovereign, and insofar as you can relate the two meters this corresponds to about 12 on scale 2 of the Tramex. What happens if you are a few points above this level, I do not know.
Its sense to use a meter - the cost of epoxy is high, not to mention the labour in cleaning off a hull . Ships and haporth of tar etc!. You can hire a meter for about £40 - pm me if you want details. And Stephenh's commendably scientific approach is an excellent way of using one.
Heating to dry off is not really a good idea - except that it allows a commercial yard to get your boat through quicker! The reason its not good is that all you are doing is drying out a hygroscopic solution inside the laminate but leaving it there. When the heat is removed , this now more concentrated solution will immediately start trying to suck moisture back in and epoxy is still permiable to water. Less so that poly, but still premiable. Plus you have an inside surface of poly to let moisture in too.
So what you need to do is to remove these hygroscopic salts as much as possible. You do this by frequent washing of the laminate surface with fresh water once you have got rid of the gelcoat. Once all the hygroscopic salts etc have gone, the laminate then dries to an acceptable levelk very quickly.
One thing worth mentioning about meters. I found that you could easily detect dampness on the inner surface of a laminate from the outside of a hull even using Sovereign. Admittedly the laminate concerned was maybe 6mm, but it does mean that when you find spot high readings with a meter you first need to look inside to see if there is a reason. Dont just jump to the conclusion thatb the laminate is wet.
G
Guest
Guest
Birdseye and Stephenh .....
This is a much better and reasonable answer ....
The point about Hygroscopic is the nut that cracks the whole issue ... plus there are other issues such as wicking along fibres, dry resin voids etc.
Many people do not realise and it is carefully passed over by the trade ... peeling is a great way to remove gel ... but it can in fact leave a hull with voids and defects unopened. All the powerwashing etc. after will not clear out the styrenes and other chemicals that lead to moisture intake again.
Blasting when done correctly is a better way - but of course yards don't like it as it is time consuming, leaves a hell of a mess, is costly etc. But it has two advantages :
a) It breaks open those voids and allows them to be cleaned out, it finds the weak points where resin hasn't done its job.
b) In having a slurry mix blasted - it starts the cleaning process immediately ...
It takes a great deal less power washing off after blasting than peeling ... so balance is struck.
This is a much better and reasonable answer ....
The point about Hygroscopic is the nut that cracks the whole issue ... plus there are other issues such as wicking along fibres, dry resin voids etc.
Many people do not realise and it is carefully passed over by the trade ... peeling is a great way to remove gel ... but it can in fact leave a hull with voids and defects unopened. All the powerwashing etc. after will not clear out the styrenes and other chemicals that lead to moisture intake again.
Blasting when done correctly is a better way - but of course yards don't like it as it is time consuming, leaves a hell of a mess, is costly etc. But it has two advantages :
a) It breaks open those voids and allows them to be cleaned out, it finds the weak points where resin hasn't done its job.
b) In having a slurry mix blasted - it starts the cleaning process immediately ...
It takes a great deal less power washing off after blasting than peeling ... so balance is struck.
stephenh
Well-Known Member
Re: Birdseye and Stephenh .....
"I have for years followed the principle of learning while working..." - quote S-B-C
Me too - there's no end to it....
I have learned a lot from this post - thanks to everyone.....
"I have for years followed the principle of learning while working..." - quote S-B-C
Me too - there's no end to it....
I have learned a lot from this post - thanks to everyone.....
taratoo
New Member
What we are working now with a surveyor is to hot steam under pressure the hull in order to oblige the hydrophilous glucoles (or something like that) to absorb and absorb and satisfy their need for water(humidity) and hoping that at the end ..they 'll dry ,their need for water will be ended!
I don't know whether it makes sense to you,but trying that readings on the meter on the hull went way down.
Cheers,
Angelos.
I don't know whether it makes sense to you,but trying that readings on the meter on the hull went way down.
Cheers,
Angelos.
G
Guest
Guest
Blimey ....
Now I have a few questions .....
Did any test be carried out to identify the actual fluid and its acidity / alkilinity before this exercise ?
And how is the diluted solution to be remived from the hull once more water / moisute has been introduced ?
If the heat is increased - and steam is a violent form of local heat - when the source of heat / steam is removed - what will prevent evaporation of the moisture due to the residual heat, subsequent re-concentration of the residues and then resume intake of atmospheric moisture - returning the hull to possibly near previous state ?
I am a strong believer that there is no short-cut to opening up the voids / moisture areas and washing the Glycols, Esters and other hygroscopic residues out with pure old fashioned pressure-wash fresh water.
Interested in the run-up to this steam method .... as you say under pressure ...
Now if you were using Hot-Vac - that is a completely different ball-game and really is effective ....
Interested to see answers ... don't misunderstand me - I haven't seen this method used and am genuinely interested ...
Now I have a few questions .....
Did any test be carried out to identify the actual fluid and its acidity / alkilinity before this exercise ?
And how is the diluted solution to be remived from the hull once more water / moisute has been introduced ?
If the heat is increased - and steam is a violent form of local heat - when the source of heat / steam is removed - what will prevent evaporation of the moisture due to the residual heat, subsequent re-concentration of the residues and then resume intake of atmospheric moisture - returning the hull to possibly near previous state ?
I am a strong believer that there is no short-cut to opening up the voids / moisture areas and washing the Glycols, Esters and other hygroscopic residues out with pure old fashioned pressure-wash fresh water.
Interested in the run-up to this steam method .... as you say under pressure ...
Now if you were using Hot-Vac - that is a completely different ball-game and really is effective ....
Interested to see answers ... don't misunderstand me - I haven't seen this method used and am genuinely interested ...
fisherman
Well-Known Member
Haven't gone through all the replies, so this may have come up already. Drying out a hull for re gelcoating or repair: sheet of plastic on the ground, boat on top, then tape plastic sheet all round the hull and down to the sheet on the ground, so creating airtight seal. Put in one or two dehumidifiers, with hoses on the outlets going to the outside. Saw a FV back at the builders for repair after going ashore and losing half of one side. It was in the tent for several months, with water constantly pouring out of the dehumidifiers.
Lakesailor
Well-Known Member
So. This Passerby. Who is he? Invite him to continue his long walk.
It's very easy to wander about dispensing rubbish to all and sundry.
Get on with what you intended to do.
It's very easy to wander about dispensing rubbish to all and sundry.
Get on with what you intended to do.
Birdseye
Well-Known Member
[ QUOTE ]
Haven't gone through all the replies, so this may have come up already. Drying out a hull for re gelcoating or repair: sheet of plastic on the ground, boat on top, then tape plastic sheet all round the hull and down to the sheet on the ground, so creating airtight seal. Put in one or two dehumidifiers, with hoses on the outlets going to the outside. Saw a FV back at the builders for repair after going ashore and losing half of one side. It was in the tent for several months, with water constantly pouring out of the dehumidifiers.
[/ QUOTE ]
You might well have seen the water coming out of the dehumidifiers (probably mainly from air leaks round the plastic curtain) but if they were trying to dry a laminate you certainly saw the wrong approach. The hygroscopic (fancy word for "water loving") gunge in the laminare will simply suck water back in if it is left there, through the epoxy very slowly and through the other side of the laminate more quickly. Its a basic law of physics. Two salt solutions of different strengths seperated by a membrane try to equalise their concentrations.
Look at it this way. You can take a dish of damp table salt off your boat and dry it in the oven. If you then put that same dish back on the cabin table, it will be just as damp as it ever was in a few days. It is hygroscopic.
Haven't gone through all the replies, so this may have come up already. Drying out a hull for re gelcoating or repair: sheet of plastic on the ground, boat on top, then tape plastic sheet all round the hull and down to the sheet on the ground, so creating airtight seal. Put in one or two dehumidifiers, with hoses on the outlets going to the outside. Saw a FV back at the builders for repair after going ashore and losing half of one side. It was in the tent for several months, with water constantly pouring out of the dehumidifiers.
[/ QUOTE ]
You might well have seen the water coming out of the dehumidifiers (probably mainly from air leaks round the plastic curtain) but if they were trying to dry a laminate you certainly saw the wrong approach. The hygroscopic (fancy word for "water loving") gunge in the laminare will simply suck water back in if it is left there, through the epoxy very slowly and through the other side of the laminate more quickly. Its a basic law of physics. Two salt solutions of different strengths seperated by a membrane try to equalise their concentrations.
Look at it this way. You can take a dish of damp table salt off your boat and dry it in the oven. If you then put that same dish back on the cabin table, it will be just as damp as it ever was in a few days. It is hygroscopic.
Birdseye
Well-Known Member
Re: Blimey ....
[ QUOTE ]
If the heat is increased - and steam is a violent form of local heat - when the source of heat / steam is removed - what will prevent evaporation of the moisture due to the residual heat, subsequent re-concentration of the residues and then resume intake of atmospheric moisture - returning the hull to possibly near previous state ?
[/ QUOTE ]
Fair point. I've often wondered using that logic, how much more effective it would be to float a peeled boat in fresh water. I suspect it would be very effective at getting out the gunge.
[ QUOTE ]
If the heat is increased - and steam is a violent form of local heat - when the source of heat / steam is removed - what will prevent evaporation of the moisture due to the residual heat, subsequent re-concentration of the residues and then resume intake of atmospheric moisture - returning the hull to possibly near previous state ?
[/ QUOTE ]
Fair point. I've often wondered using that logic, how much more effective it would be to float a peeled boat in fresh water. I suspect it would be very effective at getting out the gunge.
