Steel boat damp keel/wet keel boxes RUST

[Travellingwithtoby]

Hi guys have ordered all books recommended so will read them when iv got them, I had an idea..... and given that we are all either doing all the jobs that we should have done (at home or on the boat)

I thought I would entertain you (I was going to insert a few photos but it wont let me)

So the keel boxes are supposed to be sealed. But hatches where opened, fasteners snapped off and just silicone back down and then the boat had a freshwater leak.....

So one is mostly dry, just condensation from the looks of it

And one looks to contain a good few gallons of water (still rigging up something to fit around the lead weights to suck it out it's in an awkward place.

But once dry I had a thought... argon is heavier than air, inert so if I sealed the bilge apart from a bigger and smaller hole, argon into the big hole and oxygen out the small one (candle above small one will go out) and then seal them off and hey presto no more rust? ???

I'm going mad in isolation I think!

Please feel free to pull at my leg, or both ??

 

[rogerthebodger]

Hi guys have ordered all books recommended so will read them when iv got them, I had an idea..... and given that we are all either doing all the jobs that we should have done (at home or on the boat)

I thought I would entertain you (I was going to insert a few photos but it wont let me)

So the keel boxes are supposed to be sealed. But hatches where opened, fasteners snapped off and just silicone back down and then the boat had a freshwater leak.....

So one is mostly dry, just condensation from the looks of it

And one looks to contain a good few gallons of water (still rigging up something to fit around the lead weights to suck it out it's in an awkward place.

But once dry I had a thought... argon is heavier than air, inert so if I sealed the bilge apart from a bigger and smaller hole, argon into the big hole and oxygen out the small one (candle above small one will go out) and then seal them off and hey presto no more rust? ???

I'm going mad in isolation I think!

Please feel free to pull at my leg, or both ??

In any sealed steel structure any rusting inside will consume the oxygen in the air sealed inside. Once all the oxygen is consumed no more rusting can take place.

Best way to test that a "sealed" structure is truly sealed is to pressure test.

My steel rudder is sealed and pressure tested, but I filled the hollow rudder with old engine oil so if the rudder was damaged I would see oil leaking out.

 

[AntarcticPilot]

Just a thought - and probably impractical! But Hydrogen reduction is used on archaeological artefacts to convert rust back into iron. It is only used when the internal structure of an object can be destroyed, but it's very effective.

Suppose you filled the box with hydrogen and then heated it (I think red heat is enough)?

Posted somewhat tongue in cheek!

 

[srm]

In any sealed steel structure any rusting inside will consume the oxygen in the air sealed inside. Once all the oxygen is consumed no more rusting can take place.

As demonstrated by accidental deaths on merchant ships when crew enter oxygen deficient enclosed spaces such as empty tanks or chain lockers. IMO rules now require all ships to carry portable oxygen testing equipment. Fortunately, not usually a yacht problem.
To go back to the OP filling the space with an inert gas will work. However, the traditional methods were bitumen or a cement slurry. My old steel boat had encapsulated ballast in the steel keel and trimming ballast forward both bedded in bitumen.

 

[Travellingwithtoby]

Just a thought - and probably impractical! But Hydrogen reduction is used on archaeological artefacts to convert rust back into iron. It is only used when the internal structure of an object can be destroyed, but it's very effective.

Suppose you filled the box with hydrogen and then heated it (I think red heat is enough)?

Posted somewhat tongue in cheek!

Oh boy just what I needed to cheer me up ??

 

[Travellingwithtoby]

In any sealed steel structure any rusting inside will consume the oxygen in the air sealed inside. Once all the oxygen is consumed no more rusting can take place.

Best way to test that a "sealed" structure is truly sealed is to pressure test.

My steel rudder is sealed and pressure tested, but I filled the hollow rudder with old engine oil so if the rudder was damaged I would see oil leaking out.

I'm liking idea of a pressure test, can be done quite easily too

I dont think I have got 200L plus whatever onto of old oil ??

 

[rogerthebodger]

As demonstrated by accidental deaths on merchant ships when crew enter oxygen deficient enclosed spaces such as empty tanks or chain lockers. IMO rules now require all ships to carry portable oxygen testing equipment. Fortunately, not usually a yacht problem.
To go back to the OP filling the space with an inert gas will work. However, the traditional methods were bitumen or a cement slurry. My old steel boat had encapsulated ballast in the steel keel and trimming ballast forward both bedded in bitumen.

The ballast in the steel keel is encapsulated bitumen mainly to keep the ballast in place. I welded steel plates on top of my ballast to seal the keel air tight to prevent rusting particularly where the keel is attached to the hull plating

 

[rogerthebodger]

I'm liking idea of a pressure test, can be done quite easily too

I dont think I have got 200L plus whatever onto of old oil ??

Find some local that does oil changes for cars and trucks. You may be able to beg for some fro free or very low cost.

I am using one of the sections in my keel as a fuel tank filled with diesel oil that also prevents rusting and is also great finding leaks in welds.

Used to be used on canal boat hulls. Paint the outside with whitewash and the inside with diesel oil. If there is a leek the diesel will show up in the whitewash.

 

[srm]

I dont think I have got 200L plus whatever onto of old oil ?

Marinas often have a tank for the disposal of waste oil. You may be able to siphon enough off.

May take a few midnight trips though - I had a slight disagreement with an officious attendant on one of the Dart marinas when filling a water can in my dinghy from a pontoon tap. Decided to come clean "I am stealing your water - is it a problem?"

 

[Travellingwithtoby]

Find some local that does oil changes for cars and trucks. You may be able to beg for some fro free or very low cost.

I am using one of the sections in my keel as a fuel tank filled with diesel oil that also prevents rusting and is also great finding leaks in welds.

Used to be used on canal boat hulls. Paint the outside with whitewash and the inside with diesel oil. If there is a leek the diesel will show up in the whitewash.

Well the aft of my keel is fuel 27 gallons of it, and apparently needs cleaning (building a fuel polisher)

The next section is where the water bladder is (the damp one)

Next access panel is the ballast ( and where the fresh water accumulated

And then there is the mystery one.. two welded fittings sounds hollow waiting on my boroscope so I can check it out as there is no access panel (yet)

No idea why it wont let me upload images! Greer

Marinas often have a tank for the disposal of waste oil. You may be able to siphon enough off.

May take a few midnight trips though - I had a slight disagreement with an officious attendant on one of the Dart marinas when filling a water can in my dinghy from a pontoon tap. Decided to come clean "I am stealing your water - is it a problem?"

Hehe midnight trips, reminds me of miss spent youth!

Haha I love that! I have had a few looks recently filing my big 60L drum and other various containers on the dart ?

 

[john_q]

Fellow steel boat owner with ballast in the keel. I was told that used engine oil contains contaminates so it is better to use new oil, I choose Hydraulic oil which was lighter and cheaper.

ON NO ACCOUNT use cooking oil, I did and I am still clearing up the mess

 

[srm]

I choose Hydraulic oil

I seem to remember being told that hydraulic oil was much better than engine oil for protecting steel. Can not remember the details but possibly due to no additives and not being hygroscopic.

 

[Travellingwithtoby]

Fellow steel boat owner with ballast in the keel. I was told that used engine oil contains contaminates so it is better to use new oil, I choose Hydraulic oil which was lighter and cheaper.

ON NO ACCOUNT use cooking oil, I did and I am still clearing up the mess

Cooking oil? ? that goes in the fuel tank! Hahahahaha

Thanks for the advice I will look into it!

I seem to remember being told that hydraulic oil was much better than engine oil for protecting steel. Can not remember the details but possibly due to no additives and not being hygroscopic.

More than likely I will do some googling!

Thanks guys!