Letter 11225

How can Anodized Aluminum be made "Dishwasher Safe???" 

Hi,

I am a partner of a giftware manufacturing company in the Philippines. Mainly we work with painted finishes on GI and sometimes use BI. This is the extent of our 'techincal' metal stuff, so from here on, I speak as a pure "non-professional."

One of our customers has requested us to supply them with food grade anodized aluminum. In fact we did already this year and it was quite a success. The problem however, despite being (FDA standard) food grade, was that the anodizing washed off!! (the items are tumblers, bowls and the like). This year the customer - understandably - wants them "dishwasher safe."

We are stumped and have consulted every local "expert" we can find but are still no closer to a solution. Any advice, any help anyone can offer would be much appreciated. Thanks in advance!

Anthony Barker-Benfield
DecorGifts Inc - Manila, Philippines

The alkalinity of dishwashing solution may have dissolved the anodic coating. If you can specify non-alkaline detergent, perharps it will stay dishwasher safe.

Dado Macapagal
- Toronto

Boy, that's a good one! Basically, an anodized surface is an anodized surface and is subject to attack from the strong caustic detergents that might be used in a dishwasher. Maybe a teflon impregnated anodizing or an autoclave-safe anodized surface or a thicker hardcoated surface might help. I think you're into an area of proprietary coatings though.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

I recently bought a hamburger press only to be disappointed at what the dishwasher did to it. It occurred to me a Teflon coating would do the trick. Wish someone would coat hamburger press w/ Teflon. I'd buy it.

Earl Dean Woody
- Greenville, South Carolina

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