Q. I am trying to preserve a 25-year-old hardwood toddler table and chairs. It’s in pretty good shape, but the legs of the table were in some standing water and now retain a jagged-edged water-line an inch or two from the bottom. I sanded the jagged lines, but realize the impact is not superficial and sanding doesn’t do the trick. Can you suggest a solution? Online suggested oxalic acid, but I am not sure where to even find it, assuming it is the right solution.
— MS. MICHAEL HUBNER
A. I have to presume a thing or two before answering. Is the finish stained and varnished? If so, and the color is the same above and below the water line, then try rubbing the line with Mr. Clean Magic Eraser. No luck? Sand all legs lightly and apply an oil-based polyurethane varnish, sold in paint stores. This will darken the finish, but should cover any water lines and other blemishes. Oxalic acid is a bleaching agent, but not good for water stains on wood. As a last resort, you might be able the fade out the water line by treating with a weak bleach/water solution. Try 1 part bleach and 5 parts water and see what happens. If that works, be sure to rinse the area before finishing.
Q. I’ve lived in my house 22 years and have always had a problem with mold on the ceiling of my downstairs bathroom. The bathroom has a window and a good ceiling fan. I’m redoing the bathroom upstairs which is directly above it, and am pulling up the old underlayment and subfloor as well as the old insulation. My question to you is, should I replace the insulation in the floor or do you think that the insulation may be contributing to the mold in the downstairs bathroom? I have never had a mold problem in the upstairs bathroom, and there is no fan, just a window there. I have asked a couple of builders this question, and get different answers.
— PATRICIA HADIDIAN
A. If you take out the old insulation, and it was not wet or damp or moldy, simply put it back or put in new as you renovate the rooms. I can’t figure why you have mold in the downstairs bathroom, except that you are not using the exhaust fan properly. The right way is to turn it on during and after showering, bathing, etc. with the door open. And make sure it is blowing bathroom air outdoors. It would be interesting to hear what the two builders’ answers are.
Q. My house is four years old. Since the beginning, I have had problems with mold or mildew. It is on the alarm switch and the switch plate in the front of the inside of the house. The mold is on the registers for the air conditioning in the rooms of the house. We also have puddles in the dryer. I had the house inspected and they said I had a condenser and coil mismatched. Do you know what is happening and what can I do about it?
— MERLENE DAVIS
A. My goodness, there are a lot of questions about mold, but since they were asked, I feel obliged to answer. For those switch plates, the house is very tight and water vapor builds up by breathing, cooking, bathing, and washing. The plates are cool, and the vapor condenses on them. You could reduce the moisture in the air (the A/C should do it), but an easy fix is to buy foam switch and outlet covers at any hardware, take off the plates, insert the foam covers and put the plates back on. In fact, put the foam covers under all the plates in the house.
The inspector did you no favors when he told you what was wrong, but ignored advice on how to fix it. Have an HVAC (heating, ventilation and air conditioning company fix the mismatched system.
Q. I have a 1/2-inch crack in my driveway between driveway and foundation. Should I fill it? With what? No. 2: The nails popped on my deck; they are rusting a bit, so I reset them and then added a drop of Super Glue to each one. How long do you think they will last?
— KELLY BEATTY, CHELMSFORD
A. Is water running into the crack and causing foundation problems? If not, leave the crack open for water to drain. If there are foundation leaks, dig out that crack as deep as practical, and fill it with mortar, and pack it down thoroughly. No. 2: Maybe the nails will last a while longer, but they’ll continue to rust, but when they do pop, pull them all out and insert a hot zinc-dipped galvanized common nail in their place. They will never pop again.
Globe Handyman on Call Peter Hotton is also in the g section on Thursdays. He is available 1-6 p.m. Tuesdays to answer questions on house repair. Call 617-929-2930. Hotton (firstname.lastname@example.org) also chats online about house matters 2-3 p.m. Thursdays. To participate, go to www.Boston.com.