Protect door with a finish, repair cracks in plaster & more

Dear James: My wood front door is still in good condition. When I tried to refinish with a clear coat, it flaked off. What type of finish will last longer this time? — Wendy L.

Dear Wendy: A properly stained and finished natural wood front door is beautiful and should remain that way for many years. Over time it will need to be refinished to bring back its original appearance. Clear coatings are available that will adhere and last years.

For a long-lasting, beautiful wood door finish, three things are required — the proper finish material, the proper application technique and the proper surface preparation initially. Keep in mind that any clear coating is very thin when dry, so wood surface imperfections will show through.

The basic clear finishing material options for wood doors are urethane, varnish and shellac. Urethane and varnish harden by a curing process. This is an actual change in the chemical structure when they are exposed to air or moisture. Shellac hardens by a drying process, and therefore, it is not as durable.

If you see the words “cross linking” on a can of clear door finish, it is probably durable. Cross linking means that the chemicals bond together into large chains of molecules as they cure. Think of it as how thread is woven into a strong cloth material. These finishes also block moisture very well.

Urethanes, at least the better-quality ones, are more durable than standard varnish. Urethanes use a special chemical to create extra-strong chains when cured. This makes it more scuff- and chemical-resistant. Urethane tends to yellow slower over the years than varnish, but it does yellow some.

Make sure that you use door urethane and not floor finishing urethane. Door urethane contains ultraviolet (UV) light stabilizers to protect it and the door from the sun’s rays. UV rays can actually destroy the top surface of the wood under the finish.

You may consider having the urethane tinted for a unique look and to help protect the wood from the direct UV rays. The color pigments, even when only slightly tinted, in combination with the UV inhibitors will block more of the sun’s damaging rays.

Door urethane is also more flexible than floor urethane. It must be able to handle the door’s thermal expansions and contractions, from a hot summer afternoon to a cold winter night. Floor urethane is typically less able to withstand foot traffic and does not have to expand and contract much.

Surface preparation is key to a beautiful door no matter what finish you use.

It must be clean and dustand wax-free. Urethane has excellent adhesion, so it will stick to the dust and wax on a dirty door. If the door is not clean, within less than a year, the urethane will start to peel.

If you want a very highgloss final appearance, carefully sand the door initially. You must also lightly sand it between coats. For this type of finish, avoid water-based urethane that may lift the grain slightly. Do not use steel wool between coats, especially if you are using water-based urethane. The tiny residual steel particles can rust from moisture.

Read the manufacturer’s instructions carefully to find the length of recommended time between coats. Follow its recommended times precisely. Also, never shake urethane like you would paint. Stir it to mix it. Shaking urethane introduces fine air bubbles into it, and you can see them in the cured final surface.

How to repair plaster wall cracks

Dear James: I have an old house with plaster walls and many cracks that need to be repaired. How can I fix these so they stay fixed and are invisible?

— Julianne T.

Dear Julianne: Many older houses were built before drywall panels existed, so plaster was one of the few interior wall options. Since your house obviously is old, it has probably settled as much as it ever will, and the repaired cracks should not crack again.

Even with some cracks, plaster is still my preferred wall surface. It is a harder surface and resists water much better than drywall. This makes it more washable and easier to apply and remove wallpaper. It is also denser to minimize noise between rooms.

If you have plenty of time and you are not averse to a messy room for a few days, you and your partner should be able to repair most of the cracks. It is possible, when using certain joint compounds, to finish the entire job in one day, but don’t bet on it.

Plaster, being a very hard material, will crack when the wooden structure beneath it flexes. Many of the cracks probably start from the corners of windows or doors. Although you can fix these spots, they are natural stress relief areas. Over time, small cracks may reappear.

The quality of your repair job will determine how many years it will be until some of these cracks reappear. Trying to control the year-round humidity level inside your home will help stabilize the structural lumber and minimizing additional cracking.

The proper method to repair these cracks in the plaster is not unlike finishing drywall seams. Some people recommend widening the crack and then filling it with compound. This is usually just a short-term fix because the wall or ceiling will continue to flex at that spot and crack again.

The best crack repair procedure involves laying fiberglass joint tape over the crack and finishing it with joint compound. If you are really energetic, you can apply large sheets of fiberglass mesh over the entire wall or ceiling and then finish them with a plaster skim coat.

To fix a crack, sand the area over it. Sand an area slightly wider than the width of the fiberglass mesh joint tape. Although this step is not absolutely necessary, it does recess the area slightly. This makes it easier to eliminate a hump at the repaired spot.

When repairing plaster walls, use a professional type of dry powder joint compound (mix with water when you use it). Readymixed joint compound in a tub is quick to use, but it may not adhere to the plaster as well as the professional dry type. It is also more prone to scratching because it does not dry as hard.

Since the dry compound is usually a professional product, you may not find it at most home centers. Try building product supply outlets.

Some compounds get hard within 30 minutes after they are mixed with water. This is ideal for an experienced builder. For most do-it-yourselfers, select a slower-setting mixture that gives you an hour or two to work with it.

First, apply a 1/8-inch layer of the joint compound over the crack. Press a strip of the fiberglass mesh tape into the compound. Run a drywall knife over the tape and scrape away about half of the compound. When this is set apply thin second and third coats of compound, spreading them smooth. Using a rubber float, trowel the final coat smooth just before it sets.

Restore rusty metal patio chairs Dear James: Our metal patio chairs and table have rusted badly, but still appear reasonably sound. What is the best way to remove the rust and to repaint them? — Elle S.

Dear Elle: Any painted metal furniture made of steel or iron will rust over time. Once it starts to rust in a few spots, it will progress rapidly over more spots and under the layer of paint so, in the future; don’t wait to fix it if you start to notice surface rust.

You may or may not be able to salvage your furniture. It depends upon how badly it is rusted. In your favor is that rusting problems usually look much worse than they actually are. Rusty water runs down and stains the lower portions making it appear that they are rusted, too.

First, use the furniture as you normally would to see if it is still rigid and strong. If a chair is badly rusted, it may collapse when you sit in it. Be prepared for the worst.

If everything seems sound, take a pair of pliers and gently squeeze on any of the spots that seem rusty. Apply enough pressure to see if any spots are nearly rusted through, but not too much to crush and damage a good area.

Another, less potentially damaging, method is to hold a magnet against the rusty areas. Rust (iron oxide) is not magnetic. If you feel no attraction of the magnet in certain areas, they are probably too rusted to repair.

Assuming you found some pieces still in repairable condition, the first step is to clean off as much of the rust as possible. Although with the new rust-inhibiting paints, it is not necessary to remove every speck of rust, try to remove as much as possible.

Use a large wire brush by hand first. This will remove any of the large loose flakes of rust. Brush hard. You will not hurt the good steel underneath. Use a smaller (oneinch-long head) stainlesssteel wire brush in the tight spots. All hardware stores sell these. Use a small file in tight spots.

If you have access to compressed air, use a sandblaster.

A sandblaster attachment is inexpensive and will definitely clean off all the rust even in tight spots. Since you are blasting hard steel, you do not have to be particularly concerned about damaging the good metal.

People are often intimidated by sand blasting, but don’t be.

Do it out in your backyard. Wear safety glasses, gloves and a breathing mask. The white sand is extremely fine. Every home center store sells bags of sand. Scrub the entire piece with detergent and water when done.

Now with all, or at least most of the rust removed, it is time to start the paint process. This is a two-step process: 1) a rust-inhibiting primer and 2) a protection finish coat of the color of your choice. Oil-based primers seem to work the best. Make sure the paint can has the words “rust inhibitors” on it.

As with any paint job, follow the instructions on the paint can. People often forget to pay attention to the recommended temperature range for application. Also, be precise about the length of time between coats of paint or its effectiveness can be greatly diminished.