Handyman on Call

MARIE CRONIN, Andover

A. There are many restoration dealers in the Boston area. One such dealer is Restoration Resources in Boston, 617-542-3033. The Yellow Pages or the Internet can also be helpful. The Brosco catalog has turned posts that you might find useful. Go to an independent lumber store or big box store and ask for the Brosco catalog. If nothing appeals to you, take one of the existing posts to a woodworker who can reproduce them.

Q. The caulking on my glass door shower surround is turning black-gray. Straight bleach won’t clean it, nor will any other cleaner. What can I do? Also, water marks on my new blue stone steps are turning white with a powdery material. What is it and how can I stop it?

LINDA

A. Two headaches, both curable. For the first, dig out all that caulk and replace it with a mold-resistant caulking. Or, if the space is like a groove, then fill it with grout instead of caulking. Second headache: The white stuff is efflorescence, the leaching of lime out of the mortar. It is harmless, so you can sweep it away with a scrub brush and water. Or live with it.

Q. We recently purchased a 1930s Colonial with forced hot water radiator heat with no central air. We were quoted $28,000 to install central air conditioning. We recently saw an ad in our local paper regarding high-velocity A/C. We were wondering if you had any insights on this alternative air conditioning system.

ANNE & JOE MARVAN, Wellesley

A. Figuring about $5,000 for the A/C equipment, that leaves $23,000 for the ductwork. Pretty steep, even if the equipment costs $10,000. Steel ductwork (as for an A/C and hot air heat) is relatively simple to install in an existing house, by running ducts in closets and other obscure areas, including corners, where they can be boxed in. I suggest you get more bids. The high-velocity round ducts are easy to snake through walls and attics, but the system is expensive, maybe even more than the $28,000 bid. So, invite bids on the high-velocity system as well.

Q. I have an in-the-wall A/C unit that I think is on its way out or is done. How hard is it to take out the old and put in the new? Can I do it or should I hire someone? How can I get a new one to fit?

ANDREA, in Hotton’s chat room

A. All you need to do is unplug the unit and unscrew any supports holding the unit in place. Most if not all movable parts may be on the inside. Be careful; those units are very heavy. But wait, since you are about to buy a new one, take measurements of the opening to an appliance dealer. Just as they took my old microwave out and put the newly purchased unit in place, they can do the same for your unit.

Those chattering pipes When a caller asked why her pipes chattered when she turned on the water, the Handyman thought it was due to loose pipes, and said to tighten them in their holders wherever visible.

Wrong, trumpeted Bill Tragakis, a friend and president of Watertown Heating and Plumbing Supply in Watertown. The problem is a loose washer in the valve. A 5-cent rubber washer can replace the loose washer, and you will be chatterless, Tragakis said. The best thing about Bill’s answer is that he is good-natured. Thanks for being nice, said the contrite Handyman.

Q. I need eight new recessed ceiling lights. One electrician gave an estimate of $3,000, which included all supplies. Another bid $400, with supplies additional. What am I missing here?

DENNIS, in Hotton’s chat room

A. Say goodbye to that $3,000 fellow. He wants $333 per fixture? Whooey. The $400 fellow sounds acceptable, depending on the cost of each fixture. Make sure those fixtures are labeled ventilated, insulated, and/or no clearance.

Globe Handyman on Call also appears in the Sunday Real Estate section. He is available 1-6 p.m. Tuesdays to answer questions on house repair. Call 617-929-2930. Hotton (photton@globe.com) also chats online about house matters 2-3 p.m. Thursdays. Go to www.boston.com.