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Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Stained stainless elevator cab problems
Q. We have recently remodeled some elevator cab interiors for a commercial office building. The walls are textured 304 stainless. Recently we noticed that some sort of liquid has been spilled on the surface of the stainless steel walls. It looks almost like a coffee spill but this stain cannot be removed with water, alcohol or stainless steel cleaner. Down near the bottom of the elevator it looks like this fluid splashed up from the floor and caused numerous light brown circular stain marks like rain drops. The staining cannot be felt. There is no pitting. It almost looks like the tarnish on silverware. I suspect the fluid was some sort of acid. Maybe some sort of cleaning solution ?
1. What do you think caused the stain?
2. Can the stain be removed? (we cannot mechanically remove the stains without ruining the finish.)
Thanks much.
elevators - King of Prussia, Pennsylvania
2002
A. Search this website and you will see many references to staining of stainless steel. How about a wax that is used by the cleaning people in the building? Also search for a single cleaning person who has an unlabeled bottle secreted in their cleaning cart. I have seen several instances of cleaning people, who with the best intentions, have used things like diluted muriatic acid
⇦this on
eBay or
Amazon [affil links] or bleach solutions for cleaning because they believed that this had some great advantage over the government issue stuff.
Or it could just be coffee. I don't want to create a witch hunt, so a training session for everyone in the building that may get at your elevator can save a lot of hassle and false accusations. Stress the importance of using the recommended cleaning materials and none other. Encourage, during the training session, the cleaning personnel to talk about what they think about the finish, and how they would maintain the surface, Send one of your engineers around the cleaning rounds to see what issues are being faced with maintenance of the elevator. A dirty looking elevator is probably one of the first things noticed by a guest, and makes a big impression.
Tom Pullizzi
Falls Township, Pennsylvania
2002
A. I suspect urine or coffee.
For urine: Try vinegar
⇦in bulk on
eBay
or
Amazon [affil links] .
For coffee: Try ammonia
⇦this on
eBay or
Amazon [affil links] solution or E.D.T.D or or biological washing powder (wet, of course!) or go to a local store and buy the type of 'Stain Devils' used to remove coffee stains from clothes.
Note:Alcohol will only remove some types of organic stains. Try acetone
⇦this on
eBay
or
Amazon
[affil links] Warning! highly Flammable!
(nail varnish remover - the smelly type!)
Best of luck with the elbow grease!
- Ireland
A. Most stainless finishes like #3 or #4 polish, which can not be repaired when scratches occur, can be buffed without harming the finish. This may augment the most successful chemical method if more is needed. If you tell me more about what the finish is, I'll give more specific advice.
Dr. Michael McGuire- Pittsburgh, Pennsylvania, USA
A. This could be either urine or coffee it can be removed with either oxalic acid ⇦this on eBay or Amazon [affil links] or acetone ⇦this on eBay or Amazon [affil links] Warning! highly Flammable! . If the surface is Brush Finish, a fine paper could be rubber in the running direction to remove the marks and restore the finish
Faizan R.metal services - Dubai, U.A.E.
Q. The elevator company is claiming that the cabin they supply is of SS304 grade. How can I make sure of it? Also what is the ideal gauge for lift cabins?
Dr. Mohan G.M.Mother & Child Hospital - COCHIN, India
December 4, 2017
A. Hi Dr. Mohan. Sorry but I don't know the ideal gauge for elevator cabins; hopefully a reader familiar with that industry or its codes will help us out.
As for knowing whether it's actually 304 SS, the very easiest way is to find out if a local scrap dealer who has a "portable alloy sorter / scrap sorter ⇦this on eBay or Amazon [affil links] X-Ray fluorescence" machine would be willing to donate a little of his time for a quick visit. These machines are super fast and quite accurate but very expensive ($40,000+ US).
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
December 2017
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