Filling a void space

[Biggles]

I want to fill a void space on my boat. Its about the size of a large shoe box. The finish when set must be waterproof i.e. not permiable.

 

I have considered liquid resin and silicone used for mould making.  Both are exothermic reactions and cause me concern.

 

I have also considered a grout or waterproof cement slurry, and finally I've considered some form of closed cell expanding foam.

 

I've attached a picture of the void.  It's impossible to get into to get much more of the rust flaking off as the access is only about the size of a tin of beans.  

 

This void is between the 2 fuel tanks with the rudder stock tube running through it. It's not leaking water in but does fill when I go hard astern so I conclude it's coming out of the rudder pole bearings which  runs inside  the round rudder tube in the photo. But that's another issue. 

 

The requirement now is to stop water entering this void and thus prevent further degradation as I don't want the end up with a perforated fuel tank.

 

Any ideas welcome. Yes I know I need to stop the water ingress in the first place but that's going to be something I'll deal with next time I'm out of the water.

 

Kevin 

[Tracy D'arth]

Too little too late comes to mind. You will have to clean out and stop that rusting else it will continue no matter what you fill the void with.

[Biggles]

1 hour ago, Tracy D'arth said:

Too little too late comes to mind. You will have to clean out and stop that rusting else it will continue no matter what you fill the void with.

 I'm fully aware of the situation, what I need is a mitigation solution or discussion, not a keyboard warrior filling their day by posting pointless and useless replies. DUH!

 

 

[jonathanA]

If you can you could do with getting as much of the loose/flaky stuff off as possible then I think one of the rust converters such as fertan or vactan. (but you probably already know that )  I'm not sure I would want to fill it with something 'permanent' maybe better to be able to see whats going on.  after the vactan maybe a good spray of engine oil or something like waxoyl to give it some protection  and that can be reapplied from time to time

[David Mack]

1 hour ago, Biggles said:

The requirement now is to stop water entering this void and thus prevent further degradation as I don't want the end up with a perforated fuel tank.

If you fill the void with any sort of spray foam/concrete/whatever, it won't stick to that rusty steel. So the water you have coming in will get down between the filler and the tank sides and never dry out, and rust quite happily. And that is likely to perforate your tanks much quicker than if you do nothing.

 

My concern is why water is able to get in at all. The rudder tube should be sealed (welded) to the back deck plate, so any water which does go up the tube in reverse comes out of the top onto the deck, and not into the boat interior.

[Biggles]

The water is getting past the seals and coming up the rudder stock then going into this void.  I hear what you say but I am able to make a form around the hole at the top and create a "lid" so to speat which can be sealed.

[dmr]

That looks bad and significant cutting out of old steel and reconstruction is the only longer term fix. In the short term I can't think of a good reliable fix but I suggest no scraping or any preparation and just try to fill that big crack with loads of silicone sealant. Work it in gently with your fingers either side of the crack then get loads into the crack. Probably do this is several layers rather than all at once.

[ditchcrawler]

How about scraping, drying and then Hull Grease as used inside Barges, I am sure @Tam & Di will know more than me about it.

[Tracy D'arth]

Biggles.

 

I am not a keyboard warrior, don't be so damn rude.

The boat is a rusty shed judging by the condition of that area, trapping moisture by filling the void is the last thing to do if you want to preserve it.  Not far away from the scrap yard.

So I will not be helping you any more you impudent bodger.

[Tam & Di]

The Dutch barge grease is known as Owatrol. You can buy sprays for it on Amazon, but they're possibly a bit pricey for a 1-off job. https://www.amazon.co.uk/Waxoyl-6141711-High-Pressure-Sprayer/dp/B019CXRV16/ref=sr_1_5

 

Tam

Edited June 29, 2023 by Tam & Di

[David Mack]

2 hours ago, Biggles said:

The water is getting past the seals and coming up the rudder stock then going into this void. 

Yes, but how and why? The rudder tube should run continuously through to the deck, so any water within it will not be able to reach that void.  Are you saying the rudder tube stops short of the deck? Or has it corroded through so that water is leaking out through a rust hole or failed weld?

[ditchcrawler]

53 minutes ago, Tam & Di said:

The Dutch barge grease is known as Owatrol. You can buy sprays for it on Amazon, but they're possibly a bit pricey for a 1-off job. https://www.amazon.co.uk/Waxoyl-6141711-High-Pressure-Sprayer/dp/B019CXRV16/ref=sr_1_5

 

Tam

He is in France so may find a yard that could do it for less

24 minutes ago, David Mack said:

Yes, but how and why? The rudder tube should run continuously through to the deck, so any water within it will not be able to reach that void.  Are you saying the rudder tube stops short of the deck? Or has it corroded through so that water is leaking out through a rust hole or failed weld?

Its a barge with wheel steering so terminates below the top deck, not a NB with a Swan neck on the top

 

[Biggles]

1 hour ago, Tracy D'arth said:

Biggles.

 

I am not a keyboard warrior, don't be so damn rude.

The boat is a rusty shed judging by the condition of that area, trapping moisture by filling the void is the last thing to do if you want to preserve it.  Not far away from the scrap yard.

So I will not be helping you any more you impudent bodger.

Good. Because your type of post is just another Twit wasting bandwidth with a pointless response. 

 

FYI my rusting pile of ....was last valued at 200k on a PX . I just have this small problem area.

3 minutes ago, ditchcrawler said:

He is in France so may find a yard that could do it for less

Its a barge with wheel steering so terminates below the top deck, not a NB with a Swan neck on the top

 

Yes thats right. If It went all the way through to the top there would be no problem.  Its wheel steering not tiller.

[magnetman]

Is this a sealed area to the sides? If it is I would be considering filling it with oil. Used lube oil or any other oil. 

 

Not a  pro on this but I'm sure if oxygen can't get there the rusting will not continue. 

 

I think you might even get away with filling it with water and putting a load of oil on top. 

 

 

 

[BWM]

Dry and coat with Owatrol, it's excellent at stopping further corrosion. Not sure I'd fill the void though as it would be useful to keep an eye on the tube.

[magnetman]

If it is accessible it could potentially be an interesting area to keep the beer cool. 

[jonathanA]

i wouldn't fancy all that loose flaky rust getting in the beer...

 

still it would bring a whole new meaning to 'Iron Brew' 

 

and not sure how it would stop the rust either... 😀

 

coat....

[magnetman]

8 minutes ago, jonathanA said:

i wouldn't fancy all that loose flaky rust getting in the beer...

 

still it would bring a whole new meaning to 'Iron Brew' 

 

and not sure how it would stop the rust either... 😀

 

coat....

I was thinking of bottles of beer. 

Or God Forbid even cans ? 

 

I was like OMG I quite like canned lager. 

[Ewan123]

Filling the void sounds like it would make it impossible to check, later down the line, whether the rust is getting worse/returning. I would have thought it better to coat the (treated/prepared) surface with a proper paint/other coating. Filling the space beyond just the inner surface of the void doesn't seem to really gain you anything as far as I can imagine.

[magnetman]

If you fill it with oil no rust can happen so it would remain unchanged*

 

*Not a corrosion specialist but makes sense. 

 

If there were a carpet perhaps one could sweep it under it and not worry. 

[Tony Brooks]

2 hours ago, Biggles said:

Yes thats right. If It went all the way through to the top there would be no problem.  Its wheel steering not tiller.

 

I have no experience of barges, but plenty of cruisers have a similar set-up and on those the older ones had a "stern gland" on top of the ruder tube, while newer ones used O rings to seal, often with a grease cap in the tube. When the bearings, stock, or O rings wear/harden, then they will leak as you describe.

 

If this were mine, I think that I would want to drop the rudder out to seal what, if any, sealing it has.

 

I wonder if it has a lip-seal at the bottom end. If all else fails, then you may be able to cut some disks of thickish rubber with a hole in the centre to be a little bit smaller than the stock, split them and fit them between the rudder and underside of the hull. Secure them up against the hull with a stainless worm drive hose clip and ideally a large washer. That will do much to baffle the water that tries to come up the shaft. Consider fitting a grease nipple in the tube just above the normal  water level, so you have a chance of filling the gap between stock & tube with grease.

 

I also wonder why whatever is at the front of the void cannot be cut a way to give better access. Despite being next to the fuel tanks, an oxyacetylene cutter should make short work of giving better access.

 

[ditchcrawler]

1 hour ago, Tony Brooks said:

 

I have no experience of barges, but plenty of cruisers have a similar set-up and on those the older ones had a "stern gland" on top of the ruder tube, while newer ones used O rings to seal, often with a grease cap in the tube. When the bearings, stock, or O rings wear/harden, then they will leak as you describe.

 

If this were mine, I think that I would want to drop the rudder out to seal what, if any, sealing it has.

 

 

 

I think thats his plan "Any ideas welcome. Yes I know I need to stop the water ingress in the first place but that's going to be something I'll deal with next time I'm out of the water."

[MtB]

3 hours ago, magnetman said:

 

I was like OMG I quite like canned l*ger. 

 

FTFY!

 

 

[blackrose]

18 hours ago, magnetman said:

Is this a sealed area to the sides? If it is I would be considering filling it with oil. Used lube oil or any other oil. 

 

Not a  pro on this but I'm sure if oxygen can't get there the rusting will not continue. 

 

I think you might even get away with filling it with water and putting a load of oil on top. 

 

Eventually the water will get under any oil or grease you put down there and it will continue corroding. 

17 hours ago, Ewan123 said:

Filling the void sounds like it would make it impossible to check, later down the line, whether the rust is getting worse/returning. I would have thought it better to coat the (treated/prepared) surface with a proper paint/other coating. Filling the space beyond just the inner surface of the void doesn't seem to really gain you anything as far as I can imagine.

 

Painting requires preparation of the steel and that looks impossible unless you can grit blast it.

 

I think you've got to stop water getting in there somehow, and keep the area dry. A picture taken from further up would be useful to see how/where the water is getting in.

17 hours ago, magnetman said:

If you fill it with oil no rust can happen so it would remain unchanged*

 

 

Until the water comes in and being heavier and more dense gets under the oil. 

Edited June 30, 2023 by blackrose

[magnetman]

4 hours ago, blackrose said:

 

Eventually the water will get under any oil or grease you put down there and it will continue corroding. 

 

Painting requires preparation of the steel and that looks impossible unless you can grit blast it.

 

I think you've got to stop water getting in there somehow, and keep the area dry. A picture taken from further up would be useful to see how/where the water is getting in.

 

Until the water comes in and being heavier and more dense gets under the oil. 

Thats an interesting point. 

 

There is some argument as to whether oxygen can get through the oil but if new water is arriving then presumably this brings its own oxygen with it. 

 

I guess the best approach for this void is to just make sure it stays dry and is suitably ventilated. Maybe if the boat is on mains power a small electric heater might be considered.