Removing tile cement from enamel bath

Posting a question from my dad...
He's removed a strip of thin tiles which were stuck along the bath edge horizontally, butting up against the wall, and wants to replace them after re-sealing the gap between the bath and the wall. It would be a better job if he could get the old tile cement off the bath enamel (it's an enamelled cast iron bath). Any ideas how to do it, preferably without wrecking the enamel?
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Andrew Gabriel
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On 22 Nov 2008 23:54:05 GMT, snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote:

Unless I am wrong tile cement softens when soaked in water but I think that might be tricky in this situation :-)
How about slowly scraping the cement away using a sharp chisel or Stanley knife until it is almost all away then using wet pot scourers ..those things sponge on one side and green abrasive stuff on the other . Unless someone knows of something that acts as a solvent on tile cement .
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BigWallop wrote:

Tile cement disolves in acids, but I wouldn't use them near an enamel bath, Some acid based toilet cleaners have warnings against using them on enamel baths.

These are good used with care; http://www.screwfix.com/prods/16530/Decorating-Sundries/Decorators-Knives/Heavy-Duty-Scraper
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Dave - The Medway Handyman
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The Medway Handyman wrote:

The enamel is just glass. That is proof against all but hydro fluoric acid.
Its the plastic baths that may have issues.
Nevertheless, I have used it on he ones I have an its oK.
I have blackend chrome work though with heavy duty descaler, and the cat pee in the bath (don't ask why they prefer it as a toilet) has ruined the plug hole chrome.

http://www.screwfix.com/prods/16530/Decorating-Sundries/Decorators-Knives/Heavy-Duty-Scraper
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The polished surface of enamel on metal is wrecked by acids. Hence all the warnings about not getting acids on enameled baths. Since that bath replaced an earlier enamelled bath which was damaged by using descaler on it, my father is fortunately already aware of this.
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Andrew Gabriel
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Andrew Gabriel wrote:

well they must have changed em then. Obviously not vitreous enamel any more on this cheap modern tat.
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I believe the mechamsism is that vitreous enamel is devitrified by acids, so you're back to a crystaline surface, the gloss finish is gone, and the rougher surface is then harder to keep clean.
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Andrew Gabriel
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Andrew Gabriel wrote:

I've seen it happen myself.
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Dave - The Medway Handyman
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Andrew Gabriel wrote:

descaler or brick acid after careful chiselling of the bigger lumps.
It wont attack the enamel, but it will the underlying iron..
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If it's the original finish on a cast iron bath it's extremely tough so just scrape it off with an old chisel, etc. Leaving it to soak by covering with a damp cloth will help if ordinary tile adhesive - but not if mortar based.
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*Forget the Joneses, I keep us up with the Simpsons.

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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