Bow Thruster Tube Blacking

[plainsman]

Is it a good idea to have the tube blacked, not doing the work myself but the yard asked if I wanted it done, not sure there is merit in doing so.  Any views on this

[Robbo]

Yes get it done.

[Jess--]

it's under the water and close to the surface so it's just as much at risk as the rest of the side of your boat

some people choose not to black the tube and have no problems in the time they own the boat but others have had tubes fail (rusted through) causing all sorts of problems including sinking the boat

[Flyboy]

28 minutes ago, Robbo said:

Yes get it done.

And the rudder tube & weed hatch.

[Robbo]

This is why should really black...

 

 

[matty40s]

40 minutes ago, Jess-- said:

it's under the water and close to the surface so it's MORE at risk as the rest of the side of your boat

some people choose not to black the tube and have no problems in the time they own the boat but others have had tubes fail (rusted through) causing all sorts of problems including sinking the boat

with canal bow thrusters, the constant silt and small stones flying about when they are used for mooring and getting off the bank means you are almost grit blasting your tube most of the time. Any protection is better than none. 

Having a brand new boat llifted in with no blacking in the tube is very common from a few builders - unforgivable really.

[David Mack]

15 minutes ago, matty40s said:

with canal bow thrusters, the constant silt and small stones flying about when they are used for mooring and getting off the bank means you are almost grit blasting your tube most of the time. Any protection is better than none. 

 

 

But presumably very little better than none, if it is all going to be rapidly blasted off.

 

The best way to stop your bowthruster from rusting is:

1: have it properly blacked,

2: never use it.

 

Or perhaps just don't go to the expense of having a bowthruster at all.

[plainsman]

OK guys, thanks for the comment.  Tube on the blacking list

[cuthound]

1 hour ago, David Mack said:

 

But presumably very little better than none, if it is all going to be rapidly blasted off.

 

The best way to stop your bowthruster from rusting is:

1: have it properly blacked,

2: never use it.

 

Or perhaps just don't go to the expense of having a bowthruster at all.

 

Or just use it sensibly.

[blackrose]

Mine's never been blacked. Thought about epoxying it a few years ago when I did the rest of the underwater hull but it was too difficult to prep properly. After 10 years it still looked as good as new, no pitting around the prop area. I'm not sure what sort of red oxide colour paint it was originally painted with, but it was still on there!

 

How many people here have painted their rudder tube? I haven't done that either and as it passes through the waterline it's probably more vulnerable to corrosion than a fully submerged BT tube. 

Edited May 31, 2018 by blackrose

[David Mack]

2 minutes ago, blackrose said:

How many people here have painted their rudder tube? I haven't done that either and as it passes through the waterline it's probably more vulnerable to corrosion than a fully submerged BT tube. 

 

Very true.

And there are people who don't black their weed hatch trunk. Which is silly as it is a lot more accessible than a bowthruster tube or rudder tube.

[RLWP]

And our rudder tube rusted through, about three inches above the uxter plate so well within reach of a paintbrush

 

Always have our weedhatch blacked, can't comment on bowthruster tubes

 

Richard

[pearley]

Of course, to do a proper job of blacking the tube it needs removable grilles on the ends so you can get an arm in. Not easy if it has welded bars over it. 

[Alan de Enfield]

4 minutes ago, pearley said:

Of course, to do a proper job of blacking the tube it needs removable grilles on the ends so you can get an arm in. Not easy if it has welded bars over it. 

A bit like having security wheel nuts fitted on your car and then throwing away the key.

[Sea Dog]

13 hours ago, pearley said:

Of course, to do a proper job of blacking the tube it needs removable grilles on the ends so you can get an arm in. Not easy if it has welded bars over it. 

If I'd had a bow thruster (which of course I haven't - who'd admit that?) my non removable grills wouldn't have stopped me blacking the tube, because I wouldn't have had any grills. Even if I'd had a bow thruster  (which of course I wouldn't admit to having) I wouldn't have suffered any issues as a result of no grills, so maybe any grills would be a bit superfluous really and more bother than they're worth if they stop you blacking the tube. Or something 

[blackrose]

I have 2 welded 10mm bars spaced quite far apart so I can get my arm in to change the prop, etc, and then 2 bars going the other way which are held on by 2 big cable ties around each joint. They hold the bars firmly but are easy to cut off if you need to. I went 5 years between dockings at one point and the cable ties were still fine. The more bars you have over a BT tunnel the less efficient it becomes. 

[pearley]

Mine has grilles made of 1inch weld mesh held by an M10 stud welded to the Hull. At some time one of these studs disappeared but the grille wasn't bent. Last year on the Curly Wurley near Walsall the prop was fouled yet again and we used the bow thruster whilst drifting to stop the front banging the concrete. It wasn't too effective and when we got back to our mooring I put my hand down the weed hatch to find a short bit of 2 X 1in the tube and one blade missing from the prop. When dry docked a couple of weeks ago I couldn't see a gap big enough for the wood to get through. 

 

The thruster still worked reasonably with 5 blades but is now restored to full health.