Pinging Furnace May Mean Replacement

Question: Our gas furnace is 14 years old, and although it operates, there’s an annoying knocking and pinging sound coming from a couple of the ducts that has seemed to have become louder over the last few years. What’s causing that, and how can we get rid of it?

P.L.,

San Clemente

Answer: “It sounds as though it could be the expansion and contraction of the heat exchanger,” says Manny Gwartz of B.J. Discount Plumbing and Heating Supplies in Garden Grove.

“Within the furnace there is a compartment that keeps the flames separate from the air that’s blown into the house. When the compartment gets warm, the fan blows air over it, which heats up and is distributed through the ducts to the house.

“When you hear noises from the ducts, that’s usually the sound of metal in the compartment expanding with the heat. If it’s doing it a lot or it’s loud, it could be that the exchanger is getting old and is developing a crack. As the metal expands and contracts, it fatigues and can break. Unfortunately, there’s not a great deal that can be done without replacing the whole furnace.”

Q: I’ve seen those pad attachments that fit onto drills that let you buff your car’s finish, but I’m leery about using them. Won’t using your drill like that damage it?

T.L.,

La Habra

A: “It’s really going to depend on the drill you have,” says Chris Bey of Crown Hardware in Santa Ana. “A cheaper drill may not be able to take the stress of running for long periods of time, which is what’s needed when polishing a car. The better quality, professional drills can run for hours without straining.”

Q: I have a set of chrome chairs from the 1940s that I’d like to restore. However, in some spots the legs have become very rusty. Is there a way to get the rust out, or should I invest in having them re-chromed?

N.W.

Placentia

A: “It all depends on the amount of work you want to put into them,” says Bill Lacy, a furniture restorer from Santa Ana. “You might try some of the professional rust-removing products available at paint stores. They’re very easy to use--just rub them on with a cloth and sponge them off. They do a pretty nice job; however, you’re probably going to have to go at the legs with a fine steel wool and rub as hard as you can. It’s not an easy job, but if you keep at it, it’ll be gone.”

Q: If there’s one thing I hate about painting, it’s masking. I’ve got French doors in my living room, and I dread the idea of masking off each pane of glass. Is there a better way to protect glass and mirrors?

D.T.,

Huntington Beach

A: “There’s a product put out by Wagner that works like a felt-tip marker,” says painter Nels Kardov from Laguna Niguel. “You just apply it to the glass, wherever you want to protect it, and it’s like coating the glass with film. After you finish painting, it scapes off.

“In my experience, though, it doesn’t work that well all the time because it doesn’t dry. However, it sure beats trying to scrape off dried paint without it.

“If it’s a real delicate job where it’s crucial that no paint gets on the glass, I’d tape it off. Or I might use a stripable coating, which is available at paint stores by the gallon. The coating uses the same principle as the masking stick--just apply it and scrape it off when you’re done.”

Q: I’ve heard about step drill bits in which you can create different-sized holes from one bit. Do these work, and are they a better investment than a set of drill bits?

G.E.,

Orange

A: “Step drill bits are basically long, pyramid-shaped bits that let you drill larger and larger holes as you push through,” says Chris Roberts of James Hardware in La Habra. “However, they’re only good when you’re drilling through something that’s thin or you just want shallow holes, since each step is only about a half-inch deep. For anything deeper than that, you’ll need a standard drill bit.”