Residue from bleach solution?

[Kev888]

I recently found an old demijohn thats been lurking in the shed for many years and then accidentally left bleach solution in it for several days. On emptying it theres a sort of rough, gritty texture to the internal suface - at first I thought it may have been etched but actually it seems to rub off (though not at all easily).

I never normally soak with bleach for long periods so not sure if these are likely to be solids precipitating out of the bleach solution or not. If not guess it'd be dirt thats only been partially cleaned off. Anyone had this before?

Cheers,
Kev

[pdc]

when i worked in a supermarket i was a bit careless with the box knife. In the morning there was a white powdery residue on the floor where the bleach leaked and then dried.

[Kev888]

oops Yes I thought it may be possible, but in my case they didn't dry which is why I'm wondering about it.

Perhaps this is of interest more for the principle (i.e. can it happen), as I'm already unenthusiastic about using the demijohn if there's a possibility something odd is going on.

Cheers
kev

[kane]

i came across this when looking to clean some demi johns up

http://www.aeroandclarkie.co.uk/cleaningdemijohns.htm

seems its the same thing happening, i think they used rice and vinegar to clean it off.

Cheers
Kane

[Kev888]

Crikey - its amazing whats out there - thanks very much for the link!

Its not entirely certain/clear, but it looks like it may indeed have been the bleach somehow sticking stuff to the inside, certainly thats what the page suggests they put it down to. Interseting stuff.

thanks again,
Kev

[maxashton]

It's scale. It'll do it with soda crystals as well. Vinegar or citric will clean it up quickly.

[Kev888]

Thanks, thats useful - maybe its worth a go then. Strange that I've not experienced it before really, guess I've never let things soak in bleach long enough for this to happen in case it attacks the things I'm cleaning. I've had a something from soda crystals, although even then I don't normally do more than soak overnight, so far its just been (relatively) loose stuff collecting on the bottom.

Oh well, you live and learn. I suppose its all those years of just bunging in Chempro SDP - great stuff for its time but not cheap.

Cheers
kev

[Aleman]

Most bleaches consist of Hypochlorite and is strengthened with soda and thickened with salt. what you are probably seeing is deposition of excess salt/soda from a saturated solution

[Kev888]

Ah, I see. I think that just about nails it then - it is indeed almost certainly a deposit from the bleach solution, and now you've even been able to name it for me

Thanks again
Kev