Pitting in the bow thruster tube

[Stuart Maddock]

Hello folks I am a new to the world of narrowboating, and I find myself with this situation.

I Have found a boat which I very much like but has previously had a survey which stated there was pitting inside the bow thruster tube, this is to be confirmed by my survey.

The previous potential buyers of the boat walked away at this point. 

Much advice has been given, some similar to the above, or that it is possible to spot weld the area within the tube thereby making good the tube, or that the tube will have to be replaced and I will be looking at a very big bill.

Advise would be welcome.    As a secondary question would this if the pitting be so severe be a safety issue.. The question is asked as if there is no point in spending on a full out of water survey I might as well save my money. 

 

[matty40s]

You have a few choices and it depends on how important the rest of the boat is to you. Quite a few boats have issues in this area, some less than 10 years old, as some of the lower end companies don't even black it before it goes into water.

Spot welding the tube will be very difficult and will probably miss pits, you will also find the worst corrosion will be where the thruster prop turns, spot welding here may well jam the unit.

Get the tube blasted and epoxy coated...get the hull done at the same time. 

Weld plates over the end and learn to steer the boat properly. 

[Rickent]

1 hour ago, matty40s said:

 

Weld plates over the end and learn to steer the boat properly. 

Couldn't agree more.

[Robbo]

Re negotiate the price of the boat to cover the cost of the replacement tube.

 

[b0atman]

Big also check that if tube perforates boat has a bund wall that will stop boat filling with water and sinking .Best advice two blanking plates welded on ends of tube .Not that expensive.

 

[Jen-in-Wellies]

Put the bow thruster on ebay and you should more than cover the cost of getting plates welded over the ends of the tube. Being new to the narrow boating world you may not know that the bow thruster "debate" is like the cassette v pumpout one. Strong emotions and opinions held and no one is ever going to convince anyone on the other side. I am of the no bow thruster and learn to steer school.

Jen

[Afloat]

25 minutes ago, Robbo said:

Re negotiate the price of the boat to cover the cost of the replacement tube.

 

then

41 minutes ago, matty40s said:

 

Weld plates over the end and learn to steer the boat properly. 

 

[Bee]

If the boat is relatively short you don't really need a bowthruster, say up to 45' any longer and they are useful but they are really a luxury item on British canals. You might also find that the tube is very thick walled and a few pits don't matter (Or the opposite...)  I haven't got one and I would like one but when I get a manoeuvre totally wrong I just shout at my wife and blame her.

[Stuart Maddock]

Thanks for all the comments, they have been helpful, and I would not disagree that one should be proficient in steering without the aid of a bow thruster, but that was not my 1st or 100th consideration in the possible purchase of the boat.  BUT that is how the boat is being sold, and the owner being well aware of the issue of the bow thruster tube without a reflection in his opinion of the value of the boat, without that feature (ie removed) the boat would be devalued, especially on resale should that ever occur. So my conclusion is that serious renegotiation of the price will occur once the survey has been done. 

Thanks again for all your comments

[WotEver]

2 hours ago, Stuart Maddock said:

without that feature (ie removed) the boat would be devalued, especially on resale should that ever occur.

That's very much a matter of opinion. For me, the existence of a BT along with all the associated problems that come with them would devalue the boat. 

[Alan de Enfield]

17 minutes ago, WotEver said:

That's very much a matter of opinion. For me, the existence of a BT along with all the associated problems that come with them would devalue the boat. 

Never buy a boat with :

A Bow thruster

A pump-out toilet

Gas central heating

An overplated hull.

[OldGoat]

2 hours ago, Alan de Enfield said:

Never buy a boat with :

A Bow thruster

A pump-out toilet

Gas central heating

An overplated hull.

Not a huge problem to replace a pump out loo with a ------, if you find the former doesn't work for you..

The other three can be expensive to remove and convert to 'whatever' 

[Markinaboat]

When we bought our current boat, the survey showed slight corrosion where the prop spins (Nobels thruster). The tube was shot blasted and when reinspected, slight  pitting was revealed with the deepest at 1.5 mm (tube is 6mm). The surveyor recommended two-pack epoxy and new tube anodes (there was just one on the port side and was 70% worn). He was very confident that providing its checked at each blacking and recoated at 4 yearly intervals, there wouldn't be any problems. 

As for for having a BT, this is the first NB I've had over many years with one. Whilst it was by no means a specific requirement, a very dodgy back after three hip replacements (no, I only have two legs!) makes pulling 25 tons against the wind difficult. I only use it occasionally as still enjoy putting my hard-earned boat handling skills gained mostly, from a small woolwich (Marcellus) and a Northwich Trader. 

Horses for courses?

[blackrose]

On 2017-6-15 at 16:31, WotEver said:

That's very much a matter of opinion. For me, the existence of a BT along with all the associated problems that come with them would devalue the boat. 

Yes, it's a matter of opinion. As we all know, any equipment can have associated problems - engines, gearboxes, inverters, generators, solar panels, etc, etc...

I can only go by my own experience. My boat is over 12 years old and I've never had a problem with the BT.

It's also possible to be able to steer one's boat perfectly adequately without a BT and also have a BT. I've steered lots of other boats which don't have BTs.

But going back to the OP's post, the first thing I'd want to know is the wall thickness of the tunnel and the depth of the pits - if that information is available.

Edited June 17, 2017 by blackrose

[WotEver]

15 minutes ago, blackrose said:

the first thing I'd want to know is the wall thickness of the tunnel and the depth of the pits - if that information is available.

And if the tube is within a watertight compartment, so if it holed it wouldn't sink the boat. 

[Stuart Maddock]

I do not know the depth of the pits as yet, as all I have been told is that the issue was discovered at a previous survey by the brokers, and the potential purchasers walked away.

The tube is not in a watertight compartment as wiring has been put in from the o/s of the watertight area which means there is no watertight integrity.

My survey will give me  the exact detail.

[Robbo]

10 minutes ago, Stuart Maddock said:

I do not know the depth of the pits as yet, as all I have been told is that the issue was discovered at a previous survey by the brokers, and the potential purchasers walked away.

The tube is not in a watertight compartment as wiring has been put in from the o/s of the watertight area which means there is no watertight integrity.

My survey will give me  the exact detail.

Sounds like you have a good bargaining chip if other potential purchases have walked away.   It only needs to be water tight to the level of the canal outside, and wiring holes can easily be made water tight again if not.