Please don't embarrass yourself further.
err... OK . Were my words in English not correct ? Forgive me but it is not my first language. I must say , in any language it is poor sport to ridicule someone in any argument without saying anything intelligent in return. Example: " your mother wears Army boots"... OK then !
But you said that the rust was CAUSED by tannic acid in the leather but it was the sweat/moisture which is why I tried to politely correct your wrongness.... This following is from WIKI ( yeh , I know not necessarily correct...but I thought you might need something easy to follow in case I further embarrass myself with my poor English skills : "Tannic acid is used in the conservation of ferrous (iron based) metal objects to passivate and inhibit corrosion. Tannic acid reacts with the corrosion products to form a more stable compound, thus preventing further corrosion from taking place. After treatment the tannic acid residue is generally left on the object so that if moisture reaches the surface the tannic acid will be rehydrated and prevent or slow any corrosion. Tannic acid treatment for conservation is very effective and widely used but it does have a significant visual effect on the object, turning the corrosion products black and any exposed metal dark blue. It should also be used with care on objects with copper alloy components as the tannic acid can have a slight etching effect on these metals.
Tannic acid is also found in commercially available iron/steel corrosion treatments, such as Hammerite Kurust."
Please lets leave it there I do not want to close this interesting thread just because you are falling all over yourself to stop me embarrassing myself. For the record, I embarrase myself all the time and do not usually care

So we can agree for you to still have your opinion that Tannic acid is responsible for the rusted welding table.