To keep nail heads from rusting, countersink, fill, and then paint
In repainting my summer house in Plymouth, I noticed the nails in my wood trim are rusting. How can I prevent that? Can I paint over them with a rust preventive? What else would be practical?
JIM KAZENIAC, Westford
The nails are probably ungalvanized, or the galvanizing is defective, because properly galvanized nails resist rust for decades. The rust preventive will work for a while, but you cannot know how long. It is the least effective method. A better way is to countersink the nails and fill them with an exterior filler before painting.This is easy if the nails are finish (headless) nails. You can also countersink regular nail heads, but it is a bit tougher. The best way is to pull the nails (not always easy) and drive in stainless steel nails in their place.
I noticed a new micro-fiber reusable dry tack cloth in the stores, and I wonder if it is any good. I have been using my old-fashioned sticky tack cloth for years to take off dust after sanding, with good results. Should I try the new one?
MARGERY PACETTI,
Osterville
Stick with the devil you know. The new cloth may be just wonderful, but I bet it is more expensive than your old one, which is probably homemade. It probably works on an electro-magnetic principle, like the Swiffer dust mop. I wanted the Swiffer for my housekeeping chores, but my wife shot that down, saying a damp sponge will work as well, even better. Oh, well.
The interior walls in my 50-year-old house are plaster on plasterboard. Now, the paint is peeling right down to the bare plaster. And the plaster seems chalky. How can I treat the plaster to keep paint on?
CONCERNED, Belmont
A possible cure is to sand off as much paint as possible, then apply one coat of a clear shellac or B*I*N, a pigmented shellac. The shellac is designed to condition and seal in the chalky plaster, allowing new paint to stick. Then apply one thin coat of a latex enamel undercoater and finish with thin coats of an eggsshell finish latex paint. You may need only one top coat over the white B*I*N if you do not change the color much.
I am renovating my kitchen on a shoestring. Can I paint my refrigerator, or should I leave that to a pro? Also, how can I mount a large graphic over my sink, just above the backsplash?
RUTH FAAS, Arlington
Yes, you can paint your refrigerator, but the orange peel finish creates problems. You cannot sand that finish easily, or even steel wool it. But you can try, using a spray enamel; the Krylon aerosol sprays are very good. The most important aspect of your paint job is thin coats. You may be better off having it professionally done, but its cost would be a good down payment for a new refrigerator. If the refrigerator is more than 15 years old, then you will lose nothing getting a new one. Other than that, live with the color until you can indeed get a new one.
As for the graphic, two suggestions:
1. Coat the wall with glue size, a coating that will prepare the wall for wallpapering. Then mount the graphic with vinyl wallpaper paste, just as you would wallpaper. Then coat the graphic with water-based polyurethane varnish; it may darken the graphic a bit, but not a lot. If you want to take that graphic with you someday, it would be extremely difficult to remove, with no vouching for its condition if you could get it off. Or, simply screw a thin layer of acrylic over the graphic instead of using polyurethane.
2. Have the graphic framed in a thin-wood frame with glass, and mount it on the wall with two brass screws driven through the sides of the frame. You can wash it regularly to keep it clean.
I just removed 11 old windows to replace them in my house. How can I give them away? I would not want them to end up in a land fill.
LORI LASS, Newton
The Building Materials Resource Center will take the windows off your hands and sell them to those who need them. The company is an independent part of the Boston Building Materials Cooperative. It is in Roxbury, and the number is 617-442-8917.
About five years ago I had my house vinyl-sided, with new gutters and downspouts. Now the fascia board, the board just behind the gutter, is stained with mold, and the gutters too are moldy. In one section I can look up and see blue sky between the back of the gutter and the fascia board. What's wrong and what can I do about it?
J.B., Peabody
What's wrong is a sloppy installation of gutters. The drip edge (the edge of the roof) is letting water drip near the back of the gutter, causing an overflow. Water dripping too close to the front of the gutter will overflow the front. Water must drip in the middle of the gutter to prevent overflow, so the drip edge can be extended to do this. That gap where blue sky is showing through should be renailed into the fascia, after the mold is killed by a bleach solution. And, wonder of wonders, the installer should do all this free, if you can find him. If not, find a competent gutter man who can diagnose this problem and fix it.
I plan to put a piece of Plexiglas on the inside of my back door that has a 24-by-22-inch window, to cover just the window itself, as a security feature. How thick should the Plexiglas be, and how big should it be, and how can I cut it? How can I attach it?
A.B., Brighton
Lots of questions, but that's OK. Plexiglas is a brand name for plastic glazing; the generic term is plexiglass. You could use that, or acrylic, or any other clear plastic other than glass. To cover a 24-by-22-inch window, it should overlap by 1 inch on all four sides, so the piece will be 26 by 24 inches, and 1/4- to 3/8-inch thick. The store where you buy the piece should cut it to size.
To attach it, drill a hole through the piece and make a pilot hole for a screw in the door. Use solid brass round-headed #8 screws 1 1/2 inches long. Space the screws every 6 inches. You'll need 16 screws, and you can ease the driving of screws into the pilot holes by coating the threads with soap. When you are done, you can rest easy.
Black mold is forming behind a picture in one of my rooms. How can I get rid of it and keep it away? Some of the brass plates behind door knobs are very bright brass. How can I get them to look antique?
LOUISE POPKIN, Arlington
Treat the mold on the wall and the back of the picture with a mix of one part household bleach and three parts water. Wear skin and eye protection when working with bleach. What is happening is that moisture is being trapped behind the picture and has no place to go. Then the mold grows. To prevent this, nail a rubber bumper (small button) in each corner, holding the frame about 1/8 inch from the wall. We hope this will work. Also, keep the humidity as low as possible. This should not be difficult in winter, if the room is heated, but will be a little harder in summer.
The brass plates are lacquered to keep them shiny. Remove the laquer with lacquer thinner and let them tarnish.
Globe Handyman on Call Peter Hotton is available 1-6 p.m. Tuesdays to answer questions on house repair. Call 617-929-2930. Hotton also chats online about house matters 2-3 p.m. Thursdays. To participate, go to Boston.com. Hotton's e-mail is photton@globe.com. 
