When to plan for a hull replate

[koukouvagia]

I had to phone the insurance co. this morning to ask where the renewal was ("in the post" of course!) so I asked what the policy was on surveys. The answer is that they will never ask for a survey for policy renewals. As long as cover is continuous, the boat can be any age and no survey is required. I imagine they'll ask for a survey before taking on an older boat, but that wasn't relevant so I didn't ask.

 

This is Haven Knox-Johnston, BTW.

 

 

Not having much else to do this afternoon, I decided to ask for a quotation from this firm for Owl. The cover I asked for was identical with the policy I've got at the moment, but it would cost me £330 more! Admittedly I wouldn't need a hull survey, but then for money I'd save I'd be able to have an out of the water survey and the peace of mind that goes with it.

[JGMarine]

As some of the more lightweight Springers were built from new with steel no thicker than 4mm, does that then mean that as soon as they have lost any steel at all, they became uninsurable, then ?

 

This is a tough call for a surveyor to make. As has been mentioned the original thickness needs to be taken into consideration as well as the current overall condition.

 

The surveyor is the eyes and ears for the insurance company and has to advise them as to whether the vessel is a good or bad risk.

 

If the surveyor gets that wrong it can be a large claim. Hence why most surveyors are cautious.

We all know that a thin boat may be ok if treated correctly. Just look at how many thin working boats are still out there.

[DeanS]

Ours asked for one at 15, got one, and then asked again at 20. We suggested they looked at the previous survay, in partiucular the line that reads to the tune of 'this boat exhibits zero wasting of the hull' and that we could send them photos of the last drydock. So far nothing back.

 

The answer the OPs question, I would never plan for overplating if i could help it.

 

If its sporatic pitting down to 4mm then i wouldnt worry much as that will be failure by weeping and i would just get good paint on it. If its overall thining, just keep an eye on it, what does the hull look like when it comes out?

 

If its caked in rust then you have an issue with you paint process. If not, your not lossing metal. Simples.

 

I would also echo the suggestion that more than three coats is not nessaray or even benifical, spend the time on prep to make sure the first coat sticks beucase if it doesnt the number that follow it is errelvent! We put on two every four years and get no rust.

 

If you getting rust when i comes out and you want to throw a few grand at the hull, i would spend it on gritblasting it back to right and getting a good paint system on it.

 

 

Daniel

 

hmmm...VERY interesting Daniel. Many Thanks. And thanks for such a fantastic forum. It's a lifeline of help...and humour....

[Speedwheel]

A fairly inexperienced surveyor was 'doing' a small Springer on my dock last year, and was going round 'tut-tutting' at how much replating was going to be needed because all his ultrasonic readings were around the 4mm mark.

 

There was also the story of an experienced surveyor going around a springer (originally 4mm), where his ultrasonic tester was showing upto 4.5mm.

 

 

If you can blow holes in the metal with a pressure washer, then it needs some work.

Edited December 22, 2010 by Speedwheel

[David Mack]

Possible, but he wasnt asking about impact damage.

 

What makes you think that? The OP asked:

 

How would I know replating was getting urgent......I doubt the boat would suddenly have a breach ...surely it would perhaps spring small leaks first....dont you think? ...

 

And I agree with Dave that impact damage to a thin section, and possibly a largish hole resulting, could well be the first you would know.

 

David

[MoominPapa]

Not having much else to do this afternoon, I decided to ask for a quotation from this firm for Owl. The cover I asked for was identical with the policy I've got at the moment, but it would cost me £330 more! Admittedly I wouldn't need a hull survey, but then for money I'd save I'd be able to have an out of the water survey and the peace of mind that goes with it.

 

We're not paying anything like that much: about £200 in total.

 

MP.

[DeanS]

What makes you think that? The OP asked:

 

 

 

And I agree with Dave that impact damage to a thin section, and possibly a largish hole resulting, could well be the first you would know.

 

David

 

 

I hadnt even thought of impact damage. Definately getting more fenders now.

[OldGoldy]

From what I've seen of our hull wear, there will indeed be a big hole, and it will be along the welded seam between the baseplate and sides. That's where our baseplate had become thin

 

Richard

 

 

Not only does the baseplate thin at the rear of the front 'swim' and at the start of the rear swim, these are the points where the bottom plate 'sacrificial edges' will wear and in extreme cases wear away the weld too! If welded both inside and out the risk is reduced slightly, but if welded only on the outside, then it'll start to weep.......

 

I seem to think this is more apparent in ex-hire craft where hirers are less likely to 'push-off' the boat when leaving moorings/lock landings or allowing the boat to hit/rub the same on approach.

 

Sorry can't think of/be arsked to find correct terminology at the mo'

[Timleech]

There was also the story of an experienced surveyor going around a springer (originally 4mm), where his ultrasonic tester was showing upto 4.5mm.

 

 

Ultrasonic testers do seem to read fractionally high sometimes.

 

 

If you can blow holes in the metal with a pressure washer, then it needs some work.

 

Done that a few times

 

Tim

[mayalld]

Possible, but he wasnt asking about impact damage.

 

Wasn't he?

 

It appeared to me that he was asking what the mode of failure might be, and asking people to confirm that it would be gradual seepage at first.

 

I simply refuted that assumption.

 

I hadnt even thought of impact damage. Definately getting more fenders now.

 

Fenders won't help much.

 

It isn't just impact damage in the way you are thinking.

 

By far the MOST likely way that a hull will breach is that you graze an underwater obstruction with a thin bit of hull.

 

Think riding over a submerged shopping trolley.

[RLWP]

This is a tough call for a surveyor to make. As has been mentioned the original thickness needs to be taken into consideration as well as the current overall condition.

 

The surveyor is the eyes and ears for the insurance company and has to advise them as to whether the vessel is a good or bad risk.

 

If the surveyor gets that wrong it can be a large claim. Hence why most surveyors are cautious.

We all know that a thin boat may be ok if treated correctly. Just look at how many thin working boats are still out there.

 

I'm sorry, but if I am paying the surveyor, how is that statement true?

 

Richard

[Timleech]

I'm sorry, but if I am paying the surveyor, how is that statement true?

 

Richard

 

The surveyor in this case doesn't directly advise the insurers, but it does give you a document on which they base their decision.

Unfortunately this '4mm' thing seems to have been adopted by some as an easy safe bet, 'anything less than 4mm must be dealt with', it saves making proper informed judgements about precise circumstances and 'where and why' a particular thickness arises.

 

Tim