Lots of white powder around seacock?

[Spirit (of Glenans)]

Post deleted

 

[Spirit (of Glenans)]

It has long been held true by many that aggresive chemical cleaners should not be used in either the heads or any sink on a boat. To help prevent any build-up of fat in the drain pipe of a galley sink it's a good idea to clean off as much grease as possible from crockery and cooking vessels with tissue before washing

 

[penfold]

On ships we use Gamazyme cleaner for toilets and sink drains; it uses bacteria to get rid of fatty deposits.

 

[Rafiki]

The sink was blocked and my other half tried putting some acidic toilet cleaner down a couple of days ago when I wasn’t on the boat, and the acid had sat in the pipes for the last 2 days.

I’ve cleared the sink and flushed some water through, but have just noticed a lot of thick white powder around the seacock. Any idea what this is?

Is it related to the acid, or to the earth lead?

I would say it was salt deposit. Suggest replacing seacock at winter lift out and sealing the threads with Loctite 572 - it really is brilliant stuff, though expensive. It is a type of thread sealer/glue that seals up in the presence of metal and the absence of air. It enables you to get the seacock in whatever position you want without the need to tighten it very hard and then leaving the handle in an awkward position.

 

[vyv_cox]

Dilute hydrochloric acid does not attack brass or bronze. When I was trying to find a DIY method to differentiate between the two I immersed them in as many household fluids as possible. None had the slightest effect.

 

[penfold]

I would say it was salt deposit. Suggest replacing seacock at winter lift out and sealing the threads with Loctite 572 - it really is brilliant stuff, though expensive. It is a type of thread sealer/glue that seals up in the presence of metal and the absence of air. It enables you to get the seacock in whatever position you want without the need to tighten it very hard and then leaving the handle in an awkward position.

That's what locking nuts are for; sealant is a good idea though.

 

[dombuckley]

Not sure I buy the leak hypothesis: if it was, the salt would be concentrated around the bottom of the fitting. However, it looks fairly evenly distributed all the way around. Salt is VERY hydroscopic: if it is dry and powdery, then it is highly unlikely to be sea-salt residue.

Whenever I see salts like that on a seacock, there is ALWAYS a bonding wire attached. Funnily enough, it seems to occur more often on bronze and DZR fittings than on cheaper nickel-plated brass: perhaps the more noble metal (and thus wider gap on the galvanic table) makes for a stronger impressed current.

I would disconnect the bonding wire, clean off all the salt thoroughly and check for any deterioration of the metal, then monitor for a couple of months to see if there is any recurrence. If not, then job done.

 

[VicS]

Not sure I buy the leak hypothesis: if it was, the salt would be concentrated around the bottom of the fitting. However, it looks fairly evenly distributed all the way around. Salt is VERY hydroscopic: if it is dry and powdery, then it is highly unlikely to be sea-salt residue.

Whenever I see salts like that on a seacock, there is ALWAYS a bonding wire attached. Funnily enough, it seems to occur more often on bronze and DZR fittings than on cheaper nickel-plated brass: perhaps the more noble metal (and thus wider gap on the galvanic table) makes for a stronger impressed current.

I would disconnect the bonding wire, clean off all the salt thoroughly and check for any deterioration of the metal, then monitor for a couple of months to see if there is any recurrence. If not, then job done.

I agree with the above'
I suspect the white powdery deposit may be sodium and/or calcium carbonate which is why I suggested testing with some dilute acid.

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