Survey Epoxied Hull

[Mikenda]

What happens as regards taking hull reading,s for a survey if the hull has been epoxied? Normaly the anti-foul is scraped back to the GRP for the reading. Does the epoxy coating get sraped as well?

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[robind]

No way!! not on my boat you dont. I have heard of those who have, and the skys fallen in on them! with who should sue who posts on the forum and all
Rob

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[boatmike]

There should be no need anyway. A surveyor may require removal of patches of antifoul if he suspects blistering underneath but in my opinion should never require the epoxy to be removed unless blistering is found and a moisture reading is required. Every surveyor has his own ideas of course but in my opinion a surveyor is entitled to investigate the presence of blisters and report their existence but not to start performing any task to determine causes that cause further damage to the boat.

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[jonjo]

> There should be no need anyway.

This suggests that moisture meters see through epoxy?

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[enterprise]

What about stress cracking or previous damage/repairs ?

I am sure you would like your surveyor to find any of these if you were buying!
A good surveyor would know where to look for such defects & for piece of mind wouldn't you want to know?

If you are a buyer & the owner refuses the surveyor permission to investigate the most important area of his survey then I would most probably assume you have something to hide, which maybe why you have epoxied the hull in the first place!

Coatings like gelshield 200 can be reapplied to the areas that have been exposed so what is the problem?

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[boatmike]

So how would you define stress cracks? And how would you remove the epoxy and where? If you want to try finding a needle in a haystack by removing random chunks of epoxy all over the place fine but you would never know if there was a repair 3 inches away from the bit you removed anyway. The only way to remove epoxy is to grind it off so where do you propose to start and how much would you remove? Why not go the wholehog and remove the gel coat too....?
Have you any experience of surveys? Have you ever performed one yourself? If not please don't ask silly questions from someone who has! The only reason I would ask for epoxy to be removed would be if I suspected there was some evidence of a problem area underneath it. Otherwise there is no point whatsoever .

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[boatmike]

You have just proved that you can't understand plain English. I said there is no reason to remove the epoxy UNLESS a moisture reading is required. What is your argument with that statement pray?

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[enterprise]

Sorry Mike,
I do have experience of surveys, but only as a buyer who has witnessed a profesional assesment.

If a surveyor has found anything to sudgest stress fractures or hairline cracks (ie from inside the hull) then wouldn't he then wish to know if they are in the flowcote or part of a bigger problem? impact damage etc.

Im sure your not sudgesting that the surveyor could see through the epoxy coating?

What is wrong with reaplying the coating to the area that has been removed?
Do you really need a grinder for epoxy?
Sorry to question your judgement but that is what these forums are for.

As a buyer I would want to know.
I do understand plain English.

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[Ships_Cat]

<<<then wouldn't he then wish to know if they are in the flowcote or part of a bigger problem? impact damage etc>>>

Your posts seem to infer that the surveyor is in control. That is not the case, he is the servant of the buyer (usually the buyer).

I don't think the surveyor wishes to see or know anything beyond what he can see - he certainly cannot demand to do so. He can only point out what he can see and what he cannot see. It is not up to a surveyor to dismantle or damage a boat in any way whatsoever to pursue possible concerns in areas he cannot see - he may raise a concern but the pursuing of that is nothing to do with him at all as he will not be paying for the reassembly or repairs from the investigation. The matter of investigation causing damage or disassembly is up to the buyer and the seller to sort out between them.

If the seller agrees to damage to or dismantling of the boat for investigation then the surveyor will look at it but the requiring of it is nothing to do with him and if he is sensible he will require a boatyard or similar to do the work. If the seller refuses the buyer permission to dismantle or damage the boat then it is entirely the buyer's decision as to what he does next on the basis of the surveyors report prepared on the basis of what he has been able to see. The seller is perfectly entitled to refuse permission and may have perfectly valid reasons for doing so.

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[boatmike]

OK fine.
To be clear I am not registered as a surveyor for insurance purposes but run a general marine consultancy with a heavy bias towards composite structural design. I have been heavily involved in the survey of superyachts and other composite vessels however as a buyers representative and advisor and have in fact been called in by surveyors to give an expert opinion when in doubt themselves.
My answers to your specific questions would be as follows.
If there were any defect visible on the inside of a hull it would probably not be minor stress cracks. It would be a pretty major structural defect. In any case we need to be aware of the laminar structure of composite and recognise that a surface crack in the resin does not necessarily indicate a crack in the structure as a whole. The best way of investigating such defects is actually utilising ultrasonics and if the transducer is placed on the laminate from the inside the epoxy coat on the outside (if there is one) usually helps to reflect the sound waves and makes analysis easier. You can also employ X-ray and ultrasonics from the outside without removing the epoxy. Interpreting the results requires experience but is often better than hacking away at the outside to "dig" for the problem. The surveyors job is to report on the problem anyway, not to repair it! If there are cracks, blisters or any other defect visible on the outside, regardless of the hull being epoxy coated or not, I would sometimes seek the permission of the owner to investigate further by removing material. Often however, grinding the epoxy, or stripping the gel coat either masks or removes the problem and achieves little. There is no other way that epoxy coatings can be removed apart from grinding or sanding that I am aware of and as they are harder than the polyester gel coat employed on most boats, are almost impossible to remove without damaging the gel coat too. Because the gel coat on the outside of the hull is effectively a layer of unreinforced resin it has very little mechanical strength in tensile, flextural, or compressive terms and it is common to see cracking both above and below the waterline on older boats in the gel coat. This is usually not significant. Polyester is not a very good moisture barrier either so gel coat really contributes very little to the structure apart from weight and cosmetic appeal. Most advanced structures (carbon,aramid etc.) don't have one at all and are better off for it! The answer to your question as to if I can see through epoxy coatings is therefore no but I cant see through pigmented gel coat either!
The most valid reason therefore for removing epoxy would be to perform a moisture reading from the structure underneath that cannot be done effectively with it there. A surveyor should certainly ask the owners permission first however and I would personally not deem it necessary to do unless there were some evidence of a problem.
My opinions however are personal. As I said before I think, each surveyor will have his own ideas.
I hope this answers your questions.

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[boatmike]

Aren't you supposed to be asleep at this time of day John?
It's peeing with rain and miserable over here and I have nothing better to do at the moment. What's your excuse? Go and build some boats!!!


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[enterprise]

Thanks John,
A well constructed answer with which I now fully understand the surveyors position & the owners reluctance for the removal of epoxy.
I didn't quite see the removal of epoxy as damage in the same way as removing antifoul is acceptable.

If a Hull is epoxied can the moisture readings be taken from inside?
Sorry about the amaturish question but I've only been boating for 10 years & still have a lot to learn!

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[Ships_Cat]

Am a night owl Mike.

Got a nice email from Nic just an hour or so ago (he is a night owl too as you may know) and says he will be in contact with you.

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[Ships_Cat]

<<<If a Hull is epoxied can the moisture readings be taken from inside>>>

Perhaps Mike or someone else with hands on experience can comment further as I am more an aluminium/steel boat person, so the following may be just a spur for them to correct or elaborate.

I think the general intention of moisture readings is to detect the moisture specifically due to osmosis (if talking of GRP not wooden hulls) in order to assess its extent. As problems due to osmosis are generally found on the outside of the hull (but not always) that is where the measurements are taken. When the boat is first lifted the moisture level will be high but that in itself is not of concern and quickly dries out leaving that entrapped in bubbles etc which may be of concern.

As has been said, if the boat is epoxied then I would have thought you would only wish to check moisture levels if there was visual evidence of damage from osmosis.

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[jonjo]

My initial reaction on reading your message and looking at your profile was to assume you knew of a technology that allowed GRP moisture levels to be assessed through a layer of epoxy.

I thought your reference to removing epoxy was because the new technology could not deal with osmosis damaged areas.

However I now realise that you expect buyers to complete on the sale of a GRP yacht with their fingers crossed in the hope there is no bad news lurking beneath a layer of epoxy. Given that moisture levels and osmosis are one of the top 3 issues that affect the value of a second-hand yacht, then I have to say I find your position extraordinary.

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[jonjo]

Re: Best price

As a boat seller one of your objectives should be to eliminate as much uncertainty as possible in the eyes of a buyer and his surveyor. This will help you get the best price.

Are a few patches in an epoxy layer not acceptable to obtain the best selling price?

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[boatmike]

Well then you obvously totally misread my post and jumped to a completely erronoius conclusion didn't you? And frankly I don't care what you think as I am only posting on this forum to try and offer help to those who need it not to have fruitless arguments with those who obviously don't.

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[boatmike]

Yes John, thats entirely correct.
I think the popular misconception is that a high moisture content is only ever found in boats that have a problem and that high moisture = poor condition.
In fact most Polyester boats (including RN minehunters!) absorb water just as wood does. The question is really does this do any harm? No not in itself but it can exacerbate a problem already there....
Thats why a moisture reading is only usually taken to determine if a hull is dry enough to repair blistering or damage, not to determine the condition of the hull. You can easily dry out a wet hull by just leaving it out of the water. Indeed if an average boat is left out during the summer months (even in the UK!) it will become very dry indeed whereas if it is left in the water for a couple of seasons it can pick up sufficient water to detect by weight alone. If we were to condemn or devalue boats for having a high moisture content they would all be worth less after 2 seasons afloat than after a period out of the water which is patently silly.
The dreaded "boat pox" that people call "osmosis" has many causes. Actually osmosis is the process by which the hull picks up water so by that definition we all have a problem because as soon as the hull goes in the water it starts to absorb water. The amount it absorbs is a function of the layup, that is, the resin, the reinforcement, the thickness and the quality. It should however not be a problem if there are no defects in the original laminate but unfortunately they are all too common. When seawater reaches a void in the laminate which is probably styrene rich already the chemical reaction can cause pressure and it is this pressure that causes blisters. That statement is (before others say it) a generalisation. There are many types of blisters with varying causes. Sometimes topsides can blister too where the styrene softens the laminate and the sun does the rest. Nothing to do with water at all! Most common though are defects between the gel coat and the surface tissue under it, but sometimes it can be traced to problems deeper in the laminate. It is therefore a waste of time checking the inside of a hull (assuming you can reach it) when trying to determine the problem which is most likely to be found in the outer layers of laminate.
Basically most surveyors will not check moisture to determine the condition of a hull that shows no blistering. Its pointless. Whatever reading is obtained it will only be an indication of the time the boat has been in the water (or out as the case may be). If a boat shows localised areas with a significantly higher moisture content than the rest of the hull though this could well indicate a problem and if I saw blisters I would want to know if this area of the hull was proportionately wetter than the rest. Epoxy coating (again performed properly on a dry hull) can be very effective in keeping moisture content to a minimum. Because of this I would not want to disturb it if all other indications (including ultrasonics) supported my opinion that the hull was in good condition and blister free. If there were indications of repairs having been done however I would look very closely as they are often performed badly.
Moisture readings are therefore a valid adjunct to other evidence but not in themselves a measure of condition taken in isolation.

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[cliff]

Re: Best price

"As a boat seller one of your objectives should be to eliminate as much uncertainty as possible in the eyes of a buyer and his surveyor. This will help you get the best price.

Are a few patches in an epoxy layer not acceptable to obtain the best selling price? "

Let's make this simple. If you or your surveyor touches the epoxy on the hull of my boat I will have your balls on a plate. Neither you nor your surveyor has any right to vandalise my craft. and I would have no hesitation in pressing charges against the perpetrator.

Next point - who is going to pay to have the epoxy patched up? surely you do not expect the seller to pay? - So we now have the situation YOU ask for permission to remove epoxy and YOU pay to have it professionally reinstated id the owner even permits it to be removed in the first place. If you don't like those terms then you can go away in short jerky motions -



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[jonjo]

Re: Best price

Is your boat for sale?

Have I ever contacted you?

Have I ever expressed an interest in purchasing your boat?

Please desist from making public threats of violence against me, we are talking generalities here.

Perhaps your protective instincts over your hull relate to a recent and expensive osmosis job? If the job was recent and from a respected yard with supporting paperwork then I might acquiesce to an owner's demand that the epoxy should be left intact.

But in general if made an offer on an epoxy coated yacht and the owner then reacted as strongly as you to the suggestion of removing some test patches I would walk away from the deal.



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