Jump to content

Over plating


Featured Posts

11 minutes ago, John Hartley said:

Very nearly Thirty years ago myself and two friends built our first narrow boat from scratch. Although not a welder I was an engineer with an ability to weld. So were the other two guys. 

From the photographs presented it seams to me that the work is of excellent quality from someone who cares about the finished job. Also from the replies to the many questions it is someone with a deep knowledge of what he does. 

Should I ever need to have my boat over-plated I would not hesitate to let him do it. 

I have never used his services nor had any sort of contact with him other than what I have seen of his work.

Just keep on doing it. Boats need guys like you.

Thank you for your kind comments 

Link to comment
Share on other sites

Another question from me if you are still taking daft questions (I know I promised not to....but)

 

After having a shiny new bottom attached,do the owners generally stick a bit of bitumen on and good to go, or do they try and extend the lifespan of their new outlay with epoxy coatings or a.n other to sides and baseplate?

 

 

Thanks

Edited by rusty69
Link to comment
Share on other sites

3 minutes ago, rusty69 said:

Another question from me if you are still taking daft questions (I know I promised not to....but)

 

After having a shiny new bottom attached,do the owners generally stick a bit of bitumen on and good to go, or do they try and extend the lifespan of there new outlay with epoxy coatings or a.n other?

 

 

Thanks

If you use two pack paint ie epoxy you must remove all traces of bitumen as it reacts to two pack 

you can put bitumen on top of two pack but not the other way round 

I understand that the over plate is new steel and would take two pack but up to the top rubbing strake is usually bitumen 

it would take a long time to strip of the old bitumen 

it is all about labour cost  two pack is five times the cost of bitumen 

and there you have it you pays your money and takes your choice 

  • Happy 1
Link to comment
Share on other sites

Is the need for a 'sacrificial edge' just a myth? My boat (not a narrow boat) has spent its life on canals (mostly French) but has also ground and scraped its way along the G.U. and K &A as well as the Wey and a whole lot of unsuitable waterways sometimes with some very iffy steering skills. It has an underwater chine where most wear would be expected to occur and this is perfectly ok.. Just being controversial you understand.

  • Haha 1
Link to comment
Share on other sites

26 minutes ago, Bee said:

Is the need for a 'sacrificial edge' just a myth? My boat (not a narrow boat) has spent its life on canals (mostly French) but has also ground and scraped its way along the G.U. and K &A as well as the Wey and a whole lot of unsuitable waterways sometimes with some very iffy steering skills. It has an underwater chine where most wear would be expected to occur and this is perfectly ok.. Just being controversial you understand.

No problem I have over plates many boats that where the sacrificial edge is completely worn away. Most in fact are  

Link to comment
Share on other sites

8 minutes ago, Martin Kedian said:

No problem I have over plates many boats that where the sacrificial edge is completely worn away. Most in fact are  

Which would suggest that the need isn’t a myth, surely?  If the sacrificial edge hadn’t worn away then would the real edge have worn through instead? Or does the sacrificial edge simply get worn away because it sticks out?

Link to comment
Share on other sites

1 minute ago, WotEver said:

Which would suggest that the need isn’t a myth, surely?  If the sacrificial edge hadn’t worn away then would the real edge have worn through instead? Or does the sacrificial edge simply get worn away because it sticks out?

I think in the first instance this edge made fabrication easier in terms of welding as time passed it became apparent it helped to protect the side of the hull 

it wears away because it is proud I have seen boats with badly worn sacrificial edges starting to get the bottom of the hull being worn  which is why I put a thicker edge on using a 20 mm round bar 

there are always exceptions to this but most boat I repair have suffered to some degree or another 

Link to comment
Share on other sites

On 17/12/2018 at 22:36, Martin Kedian said:

The minimum thickness is 6 mm as this gives longevity most new boats are built in 6 mm this includes the base plate 

some people over plate in 5 mm but I don’t think this is good practice 

I've seen overplating using 4mm plate advertised which seems a bit short sighted with 4mm being what the surveyors consider as being the minimum thickness

 

Link to comment
Share on other sites

5 minutes ago, Bloomsberry said:

I've seen overplating using 4mm plate advertised which seems a bit short sighted with 4mm being what the surveyors consider as being the minimum thickness

 

I agree 6 mm is the correct thickness 

the only time I would use less is on a boat like a small springer which sometimes is made in 4 mm to being with 

a survey on a boat of this thickness allows it to be restored to its original thickness 

Link to comment
Share on other sites

4 minutes ago, Martin Kedian said:

I agree 6 mm is the correct thickness 

the only time I would use less is on a boat like a small springer which sometimes is made in 4 mm to being with 

a survey on a boat of this thickness allows it to be restored to its original thickness 

So does this mean any slight corrosion on a Springer with 4mm plate would take the thickness below 4mm and hence rendering the vessel uninsurable ?

 

Link to comment
Share on other sites

3 minutes ago, Bloomsberry said:

So does this mean any slight corrosion on a Springer with 4mm plate would take the thickness below 4mm and hence rendering the vessel uninsurable ?

 

My understanding is that surveys done on boats with less than 6 mm when new has different requirements 

6 mm on a Springer would pull it down to far I try to use 5 mm if it’s possible 

Link to comment
Share on other sites

12 minutes ago, Bloomsberry said:

Interesting, so the decision to determine whether a boat is insurable or not is influenced by the original thickness of the hull and not the actual thickness eg 3.9mm is ok on a hull originally 4mm but not on a hull originally 6mm ?

I believe it’s correct according to the surveyor I use but they are a law unto themselves 

Link to comment
Share on other sites

Hi

 

The '4mm' minimum thickness is a complete misnomer. Insurers do not stipulate any thickness, they just go on what the surveyor says, and there are no guidelines on steel thicknesses for narrowboats anywhere. The 4mm idea has just gained momentum when it has no foundation in truth. There's even a YouTube vid somewhere of a surveyor giving a guided tour of a "pre-purchase" survey of a conventional narrowboat, at a brokerage, 6mm sided, some pitting around 2.0mmm and he says overplate the lot - everything - even the swims where there's no pitting. Total nonsense. The better approach is sand blast all plating. Backfill deeper pits (those deeper than 2.0mm) and maybe reinforce aft shoulders etc with doubled plates if worn. Maybe dress and re-weld vertical seams where worn. Epoxy coat. Boat will last.

 

Sure, overplating has it's place when someone wants to rescue one that's gone too far, and Martin does a good job too, but this 4.0mm thing is total bollocks. 

 

If you don't believe me call your insurer and ask them. Ask them what they consider is satisfactory for a minimum steel thickness for a steel boat. They don't know. Boats are all kinds of thicknesses for various reasons. Many 3mm Springers are still fine now if they have been cared for, and they don't fail surveys (or shouldn't be...)...

 

Link to comment
Share on other sites

4 hours ago, watchfuleye said:

Hi

 

The '4mm' minimum thickness is a complete misnomer. Insurers do not stipulate any thickness, they just go on what the surveyor says, and there are no guidelines on steel thicknesses for narrowboats anywhere. The 4mm idea has just gained momentum when it has no foundation in truth. There's even a YouTube vid somewhere of a surveyor giving a guided tour of a "pre-purchase" survey of a conventional narrowboat, at a brokerage, 6mm sided, some pitting around 2.0mmm and he says overplate the lot - everything - even the swims where there's no pitting. Total nonsense. The better approach is sand blast all plating. Backfill deeper pits (those deeper than 2.0mm) and maybe reinforce aft shoulders etc with doubled plates if worn. Maybe dress and re-weld vertical seams where worn. Epoxy coat. Boat will last.

 

Sure, overplating has it's place when someone wants to rescue one that's gone too far, and Martin does a good job too, but this 4.0mm thing is total bollocks. 

 

If you don't believe me call your insurer and ask them. Ask them what they consider is satisfactory for a minimum steel thickness for a steel boat. They don't know. Boats are all kinds of thicknesses for various reasons. Many 3mm Springers are still fine now if they have been cared for, and they don't fail surveys (or shouldn't be...)...

 

I totally agree, it is B******x. But if the boat is over a certain age, insurers insist on a 'Satisfactory' survey for fully comp insurance.

 

And so it is up to the surveyor to determine what minimum hull thickness is acceptable.

 

Maybe when booking a surveyor for an insurance survey you need to ascertain what the minimum hull thickness size is they are willing to accept, and if the answer is not less than 4mm then look for another surveyor ?

Edited by Bloomsberry
Link to comment
Share on other sites

  • 2 weeks later...

Hi

I replated my old springer with 6mm on the hull (shallow v) and 4mm up to the rubbing strake, blooming hard work.

 

well done Martin keep up the good work, i shan't be doing another!!!! we need good fabricators/welders like yourself.

 

Couple of photos in progression and a near complete new springer.

 

Springer

NB Alakefic

2014-11-09 10.46.00.jpg

2014-09-20 17.42.18.jpg

2014-09-14 16.40.23.jpg

2014-09-14 16.41.05.jpg

2016-04-21 17.18.56.jpg

ipad pics 032.JPG

  • Greenie 1
Link to comment
Share on other sites

Hi Martin

 

I cant take all the credit as i was led by the hand by a very good experienced welder, he'd never attempted a boat before but helped me through brilliantly.

Also some welding takes on its own artistic appearance, can anybody see anything more than a weld in the Picture?

 

My wife could and turned the photo into a picture canvas.

 

Springer

28 11 14 151.JPG

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.