I have received several questions about a stain similar to that in the image above, from frustrated readers who don’t know how to get rid of it or what that caused it. I have seen several asking questions about the same kind of stains in other contexts, so thought it would be worthwhile to post a comment about the phenomenon that I choose to call “water damage” when polishing.
These type of stains can appear when you make the mistake of using too much water when applying layers of wax polish. When the wax surface becomes too wet, the layers dissolve and a coarse, matte stain is formed which first is dark but then brightens when it dries. Many get frustade and try to get rid of the spot with even more polish, usually with the opposite effect.
But the solution is usually simple. Take a nylon cloth (women’s nylon tights) and rub like crazy over the stain. The heat that is now formed causes the wax layers to “settle” again and the stain disappears. Sometimes not entirely, but then a couple of new correct layers of polish usually will be enough for it to be no longer visible. In some more unusual cases, there is so too much wax that has been dissolved, then you need to strip the shoes of cream and wax, and then start over from the beginning.
To avoid the appearance of similar stains, you need to be strict with the use of water when working a spit-shine or a proper shine with the polish. Usually it happens when the cloth is soaked, which is avoided simply by replacing the part on the cloth regularly. If you put on a shoe cream before the polish it is important to ensure that these layers have dried thoroughly before the wax is applied. It is most common for you to encounter problems with “water damage” the times when you apply a lot of cream and polish at once.