Detergent for old enameled dishwasher tubs

[aquarijen]

Hi All,
I'm new and today I just brought home my first KD-12. I might be jumping the gun a bit, but I was thinking about dish detergents and the inside enameled surface of older dishwashers. My clawfoot bathtub is allergic to bleach and other harsh things such as lime-away. Those things eat away at the porcelain enamel and I've actually pitted the enamel of it by accident before I knew that these things should never be used on old porcelain enamel.

Dishwashing detergent can also have bleach. Won't this ruin the enamel tub? What detergents do not contain bleach and still wash well?
Thanks,
Jen

 

[launderess]

IIRC

Even older versions of Cascade and other automatic dishwasher detergents contained chlorine bleach. These were sold during the heyday of porcelain tubbed dishwashers and by all accounts there weren't large numbers of complaints regarding damage. One can only assume then the products contained other chemicals designed to buffer and or mitigate damage to DW surfaces.

IIRC from reading old appliance repair books is that the older porcelain dishwasher and washing machine tubs were designed to withstand the alkaline conditions found in most detergents and of course LCB. OTHO acids are another matter and could cause damage.

 

[aquarijen]

acids and cleaning the tub

The tub itself has dishwasher scum and sort of a dark scuz - sort of like bathtub ring. What do members use to clean the tub up the first time to assess "what they have"? I was thinking of using bon ami in order to be as gentle as possible. I've assumed that an acid like as found in barkeepers friend is "right out" and would be a bad idea.
What else can be used? Comet? Softscrub? Just stick with the bon ami and some elbow greese?

-Jen

 

[supersuds]

Some people here have recommended products such as LimeAway and CLR on their porcelain washing machines. This is just from memory. You might do a search on those terms, and it will probably show up some threads where it's discussed.

As Laundreress says, these types of tubs were very common on dishwashers and when I was growing up all DW detergents seemed to be loaded with bleach. The tubs would get banged on and rust would develop, but I don't know that bleach itself was ever an issue. They lasted in daily use for years. Of course, you can also use bleach in washing machines with porcelain tubs.

 

[sudsmaster]

The foregoing is correct: alkaline detergents and bleach do not attack porcelain enamel. At least not like acidic cleaners like Lime-Away (hydrochloric acid) or Zud (oxalic acid). These acidic products can very quickly eat through the thin glass veneer on porcelain enamel.

The silica abrasives in traditional chlorine cleanser will also wear away the glazing on porcelain enamel. Must safer is the chalk-based "Soft Scrub" and similar products that are far more gentle on such vulnerable surfaces.

In any case, I don't think there's much to worry about with an older porcelain enamel dw tub and modern enzyme-based dishwasher detergents. They don't contain chlorine or abrasives. Just don't overdo the detergent as hot temps and too much detergent can etch or haze glassware, and I don't see why the thin glass veneer on a porcelain enamel tub would be any different. The DW detergent amount should be proportional to the loading and soil load of the dishwasher.