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Please help explain what is happening to this nail. It has been in this wall filler for a good few months.

The substance being excreted was rising up forming these stalagmites, with a liquid forming on them.

Removing the nail, there were also excretions at the part that was sunken.

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    $\begingroup$ What exactly is "wall filler"? $\endgroup$ – Buck Thorn Sep 21 '19 at 11:07
  • $\begingroup$ Sorry there is no chemical composition on the products label. Its used to fill up cracks in the wall... so a type of cement that hardens once applied to a surface. $\endgroup$ – Andrew Sep 23 '19 at 6:51
  • $\begingroup$ Do you have a name for the product so we can look up its composition? $\endgroup$ – Buck Thorn Sep 23 '19 at 6:54
  • $\begingroup$ This is the product: durapaints.co.za/product/prolong-supafill might have to contact the company for chemical breakdown. $\endgroup$ – Andrew Sep 23 '19 at 7:15
  • $\begingroup$ That's probably regular gypsum (drywall) then. $\endgroup$ – Buck Thorn Sep 23 '19 at 8:18

It is such a beautiful picture, perhaps good for a chemistry book cover. It is a similar phenomenon as what happens in a so-called chemical garden. Water seems to be creeping up to the nail head, and helping in oxidation of iron salts to insoluble hydroxides. Finally the gelatinous membranes act like semi-permeable membranc in the osmosis like experiment. Garden

The figure shows several salt crystals soaked in a slightly alkaline medium.

Ref: From Chemical Gardens to Chemobrionics,Chemical Reviews, 2015, 115(16) DOI: 10.1021/acs.chemrev.5b00014

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  • $\begingroup$ Thanks for the comments - don't know much about chemistry but your answer does sound good. There does still seem to be some unknowns, but I guess that is why it is called a phenomenon. $\endgroup$ – Andrew Sep 23 '19 at 6:49

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