Q - I built a fiberglass roof over my patio 12 years ago. The green corrugated panels are beginning to fade and have developed a few leaks along the overlapped seams and around a few nails. Is there a paint and sealer that can bring back color and stop leaks?

A - Try coating panels with Filon Nuglas High Gloss Refinisher. It should help restore some of the original color, though maybe not all of it. It will help with the leaking problem and add years of extra life to the fiberglass panels.

If your panels are badly worn, you should go over them with steel wool and water before you put on the Nuglas. If the leaks are not fully sealed, use some clear silicone rubber sealant on them. Buy this stuff in cartridges to fit your caulking gun.

Any home center that carries Filon panels should be able to get you the Nuglas. Or write to Filon Division of Vistron, 12333 S. Van Ness Ave, Hawthorne, Cal. 90250.

Q - In your pieces on exterior stains for the home, you did not cover boiled linseed oil as a coating for rough wood. I treated my rough cedar home with boiled linseed oil seven years ago, and have received many favorable comments on the appearance of this home. But now some of the boards are turning black from the bottom up. What is the problem and what can I do to correct it?

A - Unfortunately, wood treated with linseed oil and left out in the weather eventually will turn black. The wood looks great at first, but then the oil begins to break down and the discoloration begins. I don't know of anything you can do to solve the problem.

Some of the major stain makers such as Olympic and Cabot offer clear penetrating "stains" that do not discolor in this manner, but I doubt you would gain anything by trying these over your existing boiled oil. I think you can expect the blackening to spread, and eventually cover the whole house. If you don't like the effect (it's fairly popular in New England as a means of simulating a very old colonial house) apply a fairly dark opaque stain made with an oil base. This should mask the existing darkness to some degree, and may help slow the darkening process by shielding your home from the rays of the sun. I won't guarantee this, but it might be worth a try.