A Derbyshire-based engineering firm recently installed 200 linear metres of stainless steel balustrading to a building - which the builders cleaners then used brick acid to clean up!

This is now leaving residues which although can be wiped off, keep reappearing. The balustrade is 6 storeys high and can be accessed by a scissor lift.

The balustrade needs a fast deep clean. We asked our experts if they had any suggestions:

Most of our experts rightly asked for more information (i.e. MSDS sheets, method of contamination such as overspray or spillage rather than direct application, but to date, this has not been forthcoming.

In the meantime however, Colin Hasson says that although not entirely certain of the base of brick acid (hydrochloric or sulphfuric) "in any case the damage seems to have been done. Conventional cleaning for stainless steel is baking soda or Johnson's Baby oil but that is for smaller applications. I think they have a chemical reaction which may be difficult to deal with. Find a stainless steel stockist and ask what they recommend. However it may not work if the surface has been damaged. Try a small patch with baby oil anyway and contemplate legal action against the builders.

Dave Adams advises that for this type of specialist cleaning task "we use a company called Tubetch International. They use any of our cleaning technologies (and others) to carry out deep cleaning on many projects.

"I have spoken to them and they have said that they can do this."

Mary de Cobos thinks that the acid has damaged the steel integrity. "It can be polished though. 3M make a coarse dark maroon pad which is used by the manufacturers to polish the steel before it leaves the factory. Take a spray can of water and keeping the surface wet work the steel along the grain.This is a very coarse pad and will damage the steel if not used correctly. With the grain is the only way steel should be cleaned or polished and only on a wet surface. Never polish nor use scratchy pads (most specifically steel wool pads) on dry stainless steel There is a grain to it and failure to work with the grain results in scratches at least and damage such as this at worst.

"The steel will polish up well. However if the steel integrity has been damaged then it will rust again fairly quickly. To prevent this happening, and because it is open to the weather I would suggest that a specific stainless steel coating or oil is applied after polishing, to a dry surface. Stainless steel is very easily damaged and this is a prime example of cleaning going wrong because someone didn't know what they were doing and this gives cleaners a very bad name indeed. Its very difficult to remedy and the steel integrity is almost always damaged for the life of the steel. New stainless just needs washing down lightly if it is oiled already, drying and re-oiling. Acid is applied (and never brick acid) when the steel has a "bloom" on it and then only for restoration purposes and only on old steel. To anyone out there who has to clean stainless steel and doesn't know how, please contact me before you do so."