| The brownish substance is "surfactant" which leached out when the primer got wet from the humidity of the shower etc..
All latex paints (as a rule) are subject to surfactant leaching (because they all have surfactant in them, and latex paint is porous).
Surfactant is a soap-like water soluble substance, it will wash off with a damp sponge.
Wash the surfactant off before painting.
You don't need to re-prime. (123 Bullseye will also leach out surfactant too).
If you want a surfactant free paint job in the bathroom, you may need to:
1. Vent the bathroom to prevent humidity build up on the walls
2. Use an oil based paint which will not leach out surfactant
Even the latex bathroom paints will leach surfactant, some less than others perhaps.
Surfactant is more noticeable on dark colors. It eventually leaches out less and less as the paint cures fully. You may have to wipe it off in the early stages of paint curing from time to time with a sponge. Use care with wiping it off the finish paint film, wait the prescribed period (see paint can label) before wiping it down, and don't press hard on the paint with the sponge because latex wall paints will burnish (shine) easily when rubbed. (this is the reason for using a sponge instead of a rag - to lessen the chance of burnishing)
On exteriors, surfactant will leach out of a new latex paint film and then eventually with additional rain etc... finally all leach out and weather off. Interiors can be a little different than exteriors.  |