Q. I am on a renovation project, which includes a flying, floating staircase. I am trying to get the old finish back, and a refinishing specialist is sanding all woodwork, then staining and finishing with polyurethane. Everything is going along well enough except for the oak treads, which are painted. I am asking him to sand them before finishing. He said he can’t refinish an oak tread that has been painted. Now what can I do?
— ROBERT GILETTI, DORCHESTER
ROBERT Giletti, Dorchester
A. He really can, but he won’t for very good reason. Oak, like mahogany and walnut, is an open-pored wood and when painted the paint fills those pores. Even a good prime and paint job will show those tiny pores like pockmarks, as a different color than the wood.
To correct this, the pores are filled with a paste wood filler, and the resulting paint is smooth and nice looking. I think oak should never be painted. Unfilled oak that is varnished will not be as shiny as other finishes, but the finish does look OK.
Your man won’t do it because it is virtually impossible to remove those pockmarks. To do so would be very costly, probably more costly than a whole new set of oak treads.
Q. We recently needed to install a new water heater. Since the floor in that area of the basement is seriously out of level, the old tank had some wedges under it to keep the tank plumb.When the new tank was installed the plumber said that he would much rather the tank rest on its provided feet, even if that meant it was out of plumb. The result is a tank that is probably 10 degrees off plumb. He used flexible stainless tubing to make the connection to the supply lines. The tank is a standard 55 gallon gas-fired water heater. My question is simply whether or not that was the right thing to do? It seems to be working fine.
— MICHAEL MIRANDA, INDIANAPOLIS
Michael Miranda, Indianapolis
A. I Googled off-plumb gas water heaters and came up with zilch. But I cannot imagine your Leaning Heater of Indianapolis safe, especially a gas-powered one. It would be easy and safe to put large, stable shims under the feet of this heater. Or call the dealer and get his opinion. The dealer, who is responsible for the warranty, would be interested.
Q. We had new gray granite steps put in. The decorative black wrought-iron beam rusted this winter and some rust got on the granite top landing. What can we use to remove the rust and what should we use to paint the decorative metal beam?
— CAROL F.
A. Add 4 ounces of oxalic acid to a quart of hot water, and carefully pour it on the granite and let dry. For the iron beam, sand off as much rust as possible, then coat it with Rust Reformer, which will turn the rust black and make it paintable. Paint with Krylon’s aerosol wrought-iron contractor’s spray paint.
Q. What’s the best product to fill dry rot?
— STEVE, IN HOTTON’S CHAT ROOM
STEVE, In Hotton’s chat room
A. Dry rot is a misnomer because moisture caused the rot, but it was dry when you found it. Chip, dig, or rake out all the decay, then treat it with bleach and rinse. Apply Minwax wood hardener, then fill the cavity with Minwax epoxy wood rot filler. Smooth off and sand smooth before repainting. Work fast when working with epoxy, it starts to harden in five minutes or less. To avoid wasting it, mix it in small batches.
Q. My 12 x 25 back deck was built three years ago with pressure treated wood and left to weather. Some areas had a sooty look and stairs leading to the yard were sooty and mossy. Last fall, I scrubbed half the area with a solution. Now I plan to have whole area power washed and maybe stained . A neighbor does power washing. I got a quote from an independent professional for labor only to stain for $700. I furnish the stain, thinking Behr. His quote is $700. Which would be preferable, oil-based stain or the alternate?
— MARY DONNELLY, WALTHAM
MARY DONNELLY, Waltham
A. The only thing that will work on a wood deck is a semitransparent stain, on bare wood. So your plan to power wash before staining is a good idea, because that will remove mold, algae, moss, and soot (probably mold), and some dirt.
Your neighbor can do the power washing, and you can leave it at that. The wood will weather nicely. The $700 for staining is a fair price. But be careful about the Behr stain, or any other brand of finish. If it is a semitransparent stain, OK. I have found Olympic, oil based, to be the best. It has to be applied on bare wood, and will last five to seven years.Peter Hotton is also in the g section on Thursdays. He is available 1-6 p.m. Tuesdays to answer questions. Call 617-929-2930. He (firstname.lastname@example.org) chats on Boston.com 2-3 p.m. Thursdays.