A couple of sites recommend spraying it with household vinegar. Wouldn't that compromise the zinc coating and make it more susceptible to early rusting? Has anyone tried this or any other method with success?
Cheryl, I was told to rub it down with burlap. Those old gunny sacks finally have a use! I haven't done this (it's on my to-do list right after I plant the milk can) but a neighbor swears by it, and it isn't the neighbor with the aluminum foil cone on his head who speaks to Ahmen-Ra down the well.
A chemist I am not, however, if my high school chemistry serves me correctly what protects the metal from rusting is not the zinc but the zinc oxide produced by oxidation. The weak solution of acetic acid in the vinegar reacts with the zinc, the dark grey coating is zinc oxide which protects the steel beneath the coating. The zinc plating without the acetic acid treatment, left to the elements, will naturally oxidize over time. Jerry
Jane... Hmmm.... burlap. Where the heck am I going to find a burlap sack? Jerry... so are you saying yes or no to the vinegar? (I totally sucked in chemistry class!)
Stop by a local coffee shop and see if they have any burlap bags the coffee beans came in that they don't want. Don't stop at Starbucks, they don't roast their own beans but some of the smaller independent shops might. Or you might have to buy a yard of burlap at a fabric store.
Even as you read this post a galvanized 10 penny nail sits in a 100 ml beaker filled with 60ml of white vinegar. Small bubbles usher forth indicating a chemical reaction is taking place. Tension mounts as the time passes. Enough time to to find some burlap sacks. Bubbles bubbles and more bubbles....... I have found galvanized nails on the ground that were dark grey. Lots of zinc oxide but iI don't know how long it took to get that way. I would try the burlap bags. My experiment may take awhile. Maybe I will just "wash' a nail in vinegar and see what happens. Jerry Nail,vinegar experiment ( photo / image / picture from Jerry Sullivan's Garden )
Jerry... you're too funny! Always the experimenter! Yes... I think I'll try the burlap bag trick. But... I still wouldn't mind knowing the outcome of this latest experiment of yours. :-D and please be careful not to spill it all over your computer!
The subject nail, burnished with steel wool to remove surface zinc oxide, remained immersed in the vinegar solution nine hours. The color obtained is now dark grey, the coating and is consistent with what would be expected with anodizing. A surface residue is removable but the zinc oxide coating remains intact. A vinegar 'washed' nail was allowed to air dry and remained dry for 11 hours. The surface would appear to have a slight reduction in the sheen obtained when obtaining the nail was burnished with steel wool but otherwise remains unchanged. Conclusions: Zinc galvanized objects immersed in a vinegar solution will, depending on the immersion time, experience a significant reduction of luster initially obtained when plated. A vinegar washed object would experience none of the desired results within the same timeframe. See photograph. Jerry Top nail immersed bottom washed ( photo / image / picture from Jerry Sullivan's Garden )
Okay Jerry... for someone who never got a good grade in chemistry class... If the burlap bag trick doesn't work.... could I rub down the tub with vinegar to reduce the shine and not cause it to prematurely rust? Keep in mind... your talking to a dummy here!