Proper Preparation Required When Plaster Wall is Painted

Question: My more than 60-year-old house has lath and plaster walls and ceilings. For some reason (perhaps dampness) we have found a paper-like covering peeling off the plaster in the bedroom. Was it customary to put such a cover over the raw plaster in those days? When we peel off this layer and get down to the raw plaster, should we apply a sealer coat before painting?

Answer: The paper could be old wallpaper. Make sure that the dampness problem, if indeed there is one, is solved before you do anything. It could be caused by a leaky pipe in the wall or a leaky roof. Before latex paint came along, you had to seal a plaster wall with shellac before applying the oil-based paints that were the norm in those days. If the plaster is in good condition and, like virtually everyone these days, you use a water-thinned paint, this shouldn’t be necessary. Be sure to apply at least two coats of paint (three for a better job), after filling all the cracks and giving the walls a light sanding. It wouldn’t be a bad idea to sand after the first coat of paint, for a really first-class job.

IN THE MAIL: My column on water purifiers (Nov. 18) brought me a good deal of mail from vendors and users of water purification units that use activated carbon filters. Several sent along laboratory test reports backing up their claims that such filters are as effective as the Seagull IV mentioned in the column. Prices for activated carbon filter units are competitive with the Seagull: The Multi-Pure, made right here in Chatsworth, was mentioned by several readers; it lists at about $225, with replacement filters about $30 each; the Amgard, from Amway Corp., lists at about $325, with filters about $40 each from Amway dealers.

The February, 1983, issue of Consumer Reports magazine devotes six pages (68-73) to water purification units, including the Seagull IV. Before you plunk down several hundred dollars on a unit that might not be right for you, take a trip to your nearest library and look up this issue of Consumer Reports.