Electroprecipitation of inorganic borates, with different solubility, within monumental stones to avoid fungal colonization

•Protection of stony materials against biodeterioration by ecofriendly compounds.•Electroprecipitation of borates of different solubility to increase their applicability.•The treatment allows the precipitation of different boron compounds.•The treatment is effective in preventing the fungal colonization.•The crystallization habit and penetrability differ depending on the material to be treated.