An Overplated Situation

[Bod]

Have a view of this topic, to see how it should be done.

There are contact details in there as well.

 

Bod

[doratheexplorer]

1 hour ago, Bod said:

Have a view of this topic, to see how it should be done.

There are contact details in there as well.

 

Bod

Interesting read.

 

Post 18 in that thread reads:

 

"I've said it before, the cheapest way into narrowboat ownership is to buy a "write off" that needs overplating the owner will be glad to see the back of it but it can be made sound at quite reasonable expense.  Yet most folk looking for a cheap boat would rather have a sound hull needing an internal refit."

 

This echoes my view, and is essentially the situation we have here.

Edited December 4, 2020 by doratheexplorer

[ditchcrawler]

4 hours ago, doratheexplorer said:

Interesting read.

 

Post 18 in that thread reads:

 

"I've said it before, the cheapest way into narrowboat ownership is to buy a "write off" that needs overplating the owner will be glad to see the back of it but it can be made sound at quite reasonable expense.  Yet most folk looking for a cheap boat would rather have a sound hull needing an internal refit."

 

This echoes my view, and is essentially the situation we have here.

I know someone who gave one away that was taking in water

[Bee]

4 hours ago, doratheexplorer said:

Interesting read.

 

Post 18 in that thread reads:

 

"I've said it before, the cheapest way into narrowboat ownership is to buy a "write off" that needs overplating the owner will be glad to see the back of it but it can be made sound at quite reasonable expense.  Yet most folk looking for a cheap boat would rather have a sound hull needing an internal refit."

 

This echoes my view, and is essentially the situation we have here.

I agree, Especially if the boat is from a better than average builder, you could actually make a bit of profit from it over a few years ownership. A bit like buyng the worst house in the best street.

[Richard10002]

9 hours ago, Bod said:

Have a view of this topic, to see how it should be done.

There are contact details in there as well.

 

Bod

That's fine if you can get the boat to Kedian, and they have the space/time to do it.

 

Do we know that the boatyard that has quoted £10k does this kind of thing every day, or once in a blue moon?

 

If the latter, every job will be a part of their learning/relearning curve.

[Alan de Enfield]

11 minutes ago, Richard10002 said:

That's fine if you can get the boat to Kedian, and they have the space/time to do it.

 

Do we know that the boatyard that has quoted £10k does this kind of thing every day, or once in a blue moon?

 

If the latter, every job will be a part of their learning/relearning curve.

 

Keidan in non-canal side.

 

If they company quoting are a non-canalside operation there will also be the cost of liftout and transport, lift off the truck,  do the weldong, then lift onto the truck, transport back to the canal and lift back in.

 

Four 'lifts' and two transport = £1000 - £2000 ????

[andy4502]

i got a 6mm hull (not sides) overplated for 4k - so i think you could get the work done elsewhere and more reasonably/good quality - pm me for details of who i used (you would need to pay for lorry/lift to workplace).

 

My boat was not as critically low as yours but i decided (like others have commented) that at least i know all about the boat and i like her

[Captain Pegg]

20 minutes ago, andy4502 said:

i got a 6mm hull (not sides) overplated for 4k - so i think you could get the work done elsewhere and more reasonably/good quality - pm me for details of who i used (you would need to pay for lorry/lift to workplace).

 

My boat was not as critically low as yours but i decided (like others have commented) that at least i know all about the boat and i like her

It’s normal practice to replate both baseplate and the lower hull sides. I think you’re saying that you only had the hull doubled. If that’s so how is the new plate joined to the existing baseplate?

[andy4502]

40 minutes ago, Captain Pegg said:

It’s normal practice to replate both baseplate and the lower hull sides. I think you’re saying that you only had the hull doubled. If that’s so how is the new plate joined to the existing baseplate?

hull survey showed pitting on base but no issue on sides, new plate has been joined in a number of welds and has good sacrificial edge - trust the bloke who did it and he knows what he is doing (Tim Carter on GU near Northampton)

 

[Captain Pegg]

55 minutes ago, andy4502 said:

hull survey showed pitting on base but no issue on sides, new plate has been joined in a number of welds and has good sacrificial edge - trust the bloke who did it and he knows what he is doing (Tim Carter on GU near Northampton)

 

I’m sure he does. Actually thinking about it there’s no real issue if it’s slightly over-sized, or even under sized, compared to the original. My survey was very particular about ensuring the new plate was also welded down the centre. That’s important to prevent it sagging and so it works with the stiffeners welded to the the top of the original plate to give the hull strength.

 

Wasn’t questioning the wisdom, it’s useful info for the OP if they choose to proceed. I may have been better to say it’s more common rather than normal practice (from what I’ve seen).

Edited December 4, 2020 by Captain Pegg

[Alan de Enfield]

11 minutes ago, Captain Pegg said:

My survey was very particular about ensuring the new plate was also welded down the centre.

As they should be, it is a common fault and what that the IMMS has notified members to check for when checking overplating has been completed properly.

Surveyor should properly calculate the effect on buoyancy and stability that the new bottom / sides / weight will have.

I re-post :

 

From the Instutute of marine surveyors :

 

Finally, the marine surveyor should remember that overplating, though a common practice, is often carried out without thought as to the unintended consequences.
We should realise that it adds weight to the vessel’s structure without adding much compensating volume and, as a direct result, the vessel necessarily sinks lower in the water. It also has a number of other unintended and often unrealised side effects.

1. By increasing the draft, it reduces the available freeboard and, therefore, the amount of reserve buoyancy.
2. It also, therefore, reduces the transverse metacentric radius (BMT), and slightly, increases the height of the centre of buoyancy (KB) usually with very little compensating reduction in the height of the centre of gravity (KG) so that the end result is a reduction in the metacentric height (GM) and a negative alteration to the characteristics of the statical stability curve i.e. a reduction in the maximum GZ value and the range of positive statical stability. [The average metacentric height of a narrowboat is about 150 mm (6 inches)].
3. It may also, depending upon where the overplating is sited, alter both the longitudinal trim and the transverse heel of the vessel with further indeterminate alterations in her statical stability curve.
4. It lowers the deck edge immersion angle and, therefore, any downflooding angle(s).
5. The double plating is usually not secured to the primary supporting structure – the shell side framing. It is also rarely fitted with centre plate plug welds and is dependent only on the edge weld for security.
6. The double plating is secured only at its edges and the greater the area of plate, the smaller the length of the attachment weld per unit area and, therefore, the greater the stresses in those welds.
7. The corrosion or pitting, being the reason for fitting the doubling plates, means the corrosion or pitting will still remain there and, if it is on the inside of the original shell plate, will still be increasing. Doubling, therefore, is merely hiding the problem, not repairing it.

[matty40s]

4 hours ago, andy4502 said:

 

 

My boat was not as critically low as yours but i decided (like others have commented) that at least i know all about the boat and i like her

We send most of our major plating work to Tim.

1. We havnt got the time.

2.Tim has the space and ability to get underneath in that space

3. Tim has got a wealth of experience with welding modern and old boats.

 

 

 

[Richard10002]

There are obviously more than just Kedian who are experienced in overplating and modifying narrowboats.

 

Given that the boat in the OP is out of the water and not safe to go back in, it would be interesting to know which “yard” it is at. Some here might have experience of them doing similar work.

 

An alternative to buying the boat and having the work done is to ask the current owner to have the work done, then buy it for £15k?

[Nut]

2 hours ago, Richard10002 said:

There are obviously more than just Kedian who are experienced in overplating and modifying narrowboats.

 

Given that the boat in the OP is out of the water and not safe to go back in, it would be interesting to know which “yard” it is at. Some here might have experience of them doing similar work.

 

An alternative to buying the boat and having the work done is to ask the current owner to have the work done, then buy it for £15k?

exactly this

[Keeping Up]

20 hours ago, Alan de Enfield said:

The corrosion or pitting, being the reason for fitting the doubling plates, means the corrosion or pitting will still remain there and, if it is on the inside of the original shell plate, will still be increasing. Doubling, therefore, is merely hiding the problem, not repairing it.

This is the one part of the statement that I take issue with. If you have pitting on the outside of the hull (as I did) and a steel plate is properly welded over the cleaned area with an all-round waterproof weld, to as good a standard as the welding of the hull construction, surely that constitutes a repair rather than just a cover-up. The fact that a pitted plate exists behind what is effectively a new bit of hull is irrelevant.

[Alan de Enfield]

1 minute ago, Keeping Up said:

This is the one part of the statement that I take issue with. If you have pitting on the outside of the hull (as I did) and a steel plate is properly welded over the cleaned area with an all-round waterproof weld, to as good a standard as the welding of the hull construction, surely that constitutes a repair rather than just a cover-up. The fact that a pitted plate exists behind what is effectively a new bit of hull is irrelevant.

 

I know where you 'are coming from' and I'd tend to agree with you, however The IIMS (who hopefully have the knowledge and experience) seem to think otherwise.

 

 

...................Furthermore, IIMS is the only professional body to offer a formal marine surveying qualification.

 

Yacht & Small Craft Professional Qualification by IIMS

[Keeping Up]

26 minutes ago, Alan de Enfield said:

 

I know where you 'are coming from' and I'd tend to agree with you, however The IIMS (who hopefully have the knowledge and experience) seem to think otherwise.

 

 

...................Furthermore, IIMS is the only professional body to offer a formal marine surveying qualification.

 

Yacht & Small Craft Professional Qualification by IIMS

But does their wealth of knowledge and experience fully comprehend the particular features of narrowboat building? Or are there also vested interests involved?

[Alan de Enfield]

6 minutes ago, Keeping Up said:

Or are there also vested interests involved?

I was trying to think what they would gain and could not find a great deal.

 

Unless they own a company involved in re-plating steel boats all I can see is them getting the job of 'signing off' the replacement as being 'to standard', but they would probably get that on an overplating job anyway.

 

8 minutes ago, Keeping Up said:

But does their wealth of knowledge and experience fully comprehend the particular features of narrowboat building?

 

Is there in reality a big difference between Dutch Barges and NB's ?

[Bee]

I think one of the things that we need to understand is that steel really needs to be looked after and sometimes the various diseases of steel are unpredictable. There can be old fashioned rust under the floor, that weird microbial thing on the outside, electrolysis just to fill in the gaps and I expect other things too. Some boats are in trouble after 20 years, some are still on their original plating after twice that and more.  I think one thing we do know is that modern coatings work better than a couple of slapped on coats of bitumen - anyway that is either banned or will be sometime quite soon.  There are hundreds of steel cruisers in Holland built with 4mm steel, plenty strong enough and with care they last for years but owners usually (not always though) expect to lift them out and paint much more frequently than  the average narrowboat built with 50% more thickness. We might have to start thinking about steel as being delicate fragile stuff that needs gentle treatment and tea and sympathy and lots of paint.

[BoatjackHorseboat]

Hi everyone, well we've had a tricky old time sorting this out. I can now see why brokerage has its place to be honest. Friends + thousands of pounds = a series of challenging conversations.

Ta for your comments and experiences. Been rereading them just. Super useful. From the mix of opinions (and other people's too) we understood that this was a pretty 50/50 call on our budget. Can totally see the merits of getting a boat that needs overplating, even purely for the reason that it'd put a bunch of other people off. And I can see the arguments against.

 

In the end we decided not to go ahead  If we'd been able to live on her with third party insurance and cruise to a yard/welder of our choice, that may have been worth a punt. However, with the hull currently paper thin and the boat a long distance from backup accommodation (Mums and Dads), the logistics of overseeing and managing the situation in Covid times looked a bit of a nightmare. Yard it's at is open air and weather dependent too, so the timescale on completing the work was erm, 'Spring'. It's an anticlimax - but I think we've made the right call in the circumstances.

 

I'll note the welders people have recommended. Be v useful if we find ourselves in the same (or hopefully a less extreme) situation with another boat.

To address something mentioned earlier, before this boat cropped up we were indeed pursuing GRP - I've even done posts here asking. We missed out on a Highbridge 32 back in the summer. However, as @doratheexplorer says, we do reckon that size is not ideal for two people to liveaboard. Possible, but not ideal.

 

The issue really is the scarcity of longer GRP boats - which unless you've been actively looking for one may not be clear. We'd be cruising Midlands, and as far as I know Fibreline and Morgan Giles are the only two narrowbeams longer than 32 foot (?). They appear v rare, which is perplexing considering they look a great solution at the lower (rustier) end of the market. Maybe historical reasons for this...?

@Alan de Enfieldyou mentioned a GRP narrowboat sold recently on ebay for 8kish - what kind was it, out of interest?

[Alan de Enfield]

10 minutes ago, BoatjackHorseboat said:

you mentioned a GRP narrowboat sold recently on ebay for 8kish - what kind was it, out of interest?

Sorry, I've recently cleard up my lap-top and deleted loads of old, 'no longer needed stuff'.

 

There were several threads and pictures - if you do a search you may find it.

[doratheexplorer]

10 hours ago, BoatjackHorseboat said:

Hi everyone, well we've had a tricky old time sorting this out. I can now see why brokerage has its place to be honest. Friends + thousands of pounds = a series of challenging conversations.

Ta for your comments and experiences. Been rereading them just. Super useful. From the mix of opinions (and other people's too) we understood that this was a pretty 50/50 call on our budget. Can totally see the merits of getting a boat that needs overplating, even purely for the reason that it'd put a bunch of other people off. And I can see the arguments against.

 

In the end we decided not to go ahead  If we'd been able to live on her with third party insurance and cruise to a yard/welder of our choice, that may have been worth a punt. However, with the hull currently paper thin and the boat a long distance from backup accommodation (Mums and Dads), the logistics of overseeing and managing the situation in Covid times looked a bit of a nightmare. Yard it's at is open air and weather dependent too, so the timescale on completing the work was erm, 'Spring'. It's an anticlimax - but I think we've made the right call in the circumstances.

 

I'll note the welders people have recommended. Be v useful if we find ourselves in the same (or hopefully a less extreme) situation with another boat.

To address something mentioned earlier, before this boat cropped up we were indeed pursuing GRP - I've even done posts here asking. We missed out on a Highbridge 32 back in the summer. However, as @doratheexplorer says, we do reckon that size is not ideal for two people to liveaboard. Possible, but not ideal.

 

The issue really is the scarcity of longer GRP boats - which unless you've been actively looking for one may not be clear. We'd be cruising Midlands, and as far as I know Fibreline and Morgan Giles are the only two narrowbeams longer than 32 foot (?). They appear v rare, which is perplexing considering they look a great solution at the lower (rustier) end of the market. Maybe historical reasons for this...?

@Alan de Enfieldyou mentioned a GRP narrowboat sold recently on ebay for 8kish - what kind was it, out of interest?

AFAIK, GRP boats longer than 32' and no more than 7' wide are rare because of the difficulties of retaining the structural integrity of the hull at that length.  GRP is not as rigid as steel.  To make it rigid, it would have to be unusually thick or have some kind of internal strengthening system, which would add cost and potential harm the usability of the interior.

 

At least that's my understanding of it.  Happy to be corrected.

 

A huge downside of GRP is that it's just not as strong as steel.  That may not be a big deal on wide rivers, when contact is rare.  But somewhere like the BCN is a different story - the narrow locks, hidden debris underwater, narrow sections past toll islands.  Boats will inevitably be knocked about and GRP boats sinking due to this do happen from time to time.  It sadly happened a couple of years ago on the BCN challenge.

[Mad Harold]

22 minutes ago, doratheexplorer said:

AFAIK, GRP boats longer than 32' and no more than 7' wide are rare because of the difficulties of retaining the structural integrity of the hull at that length.  GRP is not as rigid as steel.  To make it rigid, it would have to be unusually thick or have some kind of internal strengthening system, which would add cost and potential harm the usability of the interior.

 

At least that's my understanding of it.  Happy to be corrected.

 

A huge downside of GRP is that it's just not as strong as steel.  That may not be a big deal on wide rivers, when contact is rare.  But somewhere like the BCN is a different story - the narrow locks, hidden debris underwater, narrow sections past toll islands.  Boats will inevitably be knocked about and GRP boats sinking due to this do happen from time to time.  It sadly happened a couple of years ago on the BCN challenge.

There are grp boats longer than 32ft,but of course they are wider.

You are right about the bashing that canal boats usually contend with and fibreglass having much less tensile strength than steel will suffer more.A good thump against a sticky out object like a scaffold pole,or a proud canal wall stone will probably only dent a steel hull (providing there is a reasonable thickness) but could hole a fibreglass hull.

The advantage of fibreglass hulls is their durability (no rust) and of course the price difference between steel boats and fibreglass ones.

For people of modest means a grp cruiser is the cheapest way of getting afloat.

[Alan de Enfield]

1 minute ago, Mad Harold said:

You are right about the bashing that canal boats usually contend with and fibreglass having much less tensile strength than steel will suffer more.A good thump against a sticky out object like a scaffold pole,or a proud canal wall stone will probably only dent a steel hull (providing there is a reasonable thickness) but could hole a fibreglass hull.

The 'weakness' of GRP is certainly pronounced when a small 'sharp' object hits the side with some force and penetration is quite possible, but, hitting a bank-side square on is unlikely to do much damage at all. GRP does 'flex', is remarkably strong and very easy to 'patch'.

If it was 'that prone to weakness' I doubt the Navy would use it for their warships.

 

The lack of maintenance of GRP is a far greater benefit than the strength of steel. If you are going to do a 'Timothy West' then maybe boating is not for you anyway.

If somone does a 'Timothy West' on you - that's what insurance is for.

[doratheexplorer]

2 hours ago, Alan de Enfield said:

The 'weakness' of GRP is certainly pronounced when a small 'sharp' object hits the side with some force and penetration is quite possible, but, hitting a bank-side square on is unlikely to do much damage at all. GRP does 'flex', is remarkably strong and very easy to 'patch'.

If it was 'that prone to weakness' I doubt the Navy would use it for their warships.

 

The lack of maintenance of GRP is a far greater benefit than the strength of steel. If you are going to do a 'Timothy West' then maybe boating is not for you anyway.

If somone does a 'Timothy West' on you - that's what insurance is for.

But of course, canal boats owned by the navy have always been steel...