water damage

[tallguy]

I have an area of about 2 feet in diameter with a water ring.  the sheetrock is structurally fine, just slightly discolored.  do i need to do any special preparation before painting it.  i seem to remember some advice long ago to cover it with shellac first.

[rmichael]

Hi Tallguy,

Yes, you are right about shellac being used in the past. Some modern primer/sealers like "BIN" or "123" are in fact white pigmented shellac.

Before you paint you will need to seal out the water stain. The stain will come to the surface of latex paint.
I would spot the stain with a primer/sealer such as "Kilz" or "Coverstain". The solvent based sealers seem to "hold out" a stain better than the water based sealers.
Be sure to cover the entire stain by applying the sealer four or five inches past the edges of the visible stain.

Hope this Helps,
rmichael  pro painter