if you have the blueprint for "boots", and you place your leather, padding, and x2 soles into their respective slots, the completed item will be shown before you click on "craft" or whatever it says. I don't think regular mutated dog leather gives immunity to the puddles, but if it does, it will say so in green below it's armor resistances and above its durability.
Mutated dog leather gives better acid resistance than siphoner leather. If it doesn't make you immune to the puddles, wear mutated dog boots and mutated dog leather armor, because the resistances from both will stack, which might resist all the damage the puddles do anyway.