Small amount of water proof subtance is excused in wadu or do i have to remove it ???
Wa’alaykum as Salam wa rahmatullahi wa barakatuhu,
It is compulsory for water to completely touch every portion of the three limbs (face, hands and feet) which the Quran comands us to wash, and we should be able to wipe atleast quarter of the head.
If there is anything which prevents water from these limbs, even though it may be as small as a mustard seed or one hair, the Wudhu will not be valid.
You will have to remove the water proof substance for your Wudhu to be correct.