Checking up on aluminum wiring; restoring faded redwood siding

Q. We live in a 1968 mobile home with aluminum wiring. While it has caused us no problem, we pay almost double for fire insurance; thus we think we might have difficulty in selling the unit. Is there some safe and inexpensive way to rectify the matter? How much would it cost us to replace the aluminum wiring with copper? G. Immerwals Bothell, Wash.

Aluminum wiring, which was used in the late 1960s during a copper shortage, has a tendency to expand when heated and is relatively soft. If carelessly or improperly installed, potentially unsafe loose connections can occur. However, if there has been no problem in the last 15 years, I'd feel quite comfortable about the future.

Still, I'd have a seasoned electrician inspect the wiring. Ask him to check especially all the connections and provide a written, signed report on the condition of the existing installation.

Should the aluminum installation be found suspect, ask the electrician for a price on rewiring with copper.

If the new wiring is surface mounted - and for practical reasons it may have to be so if the aluminum is not in a conduit - an appearance problem is encountered.

You will need to make a decision based on the middle road between future resalability and present economics and/or appearance.

Q. My decade-old, untreated redwood-sided house began to change color two years ago. A local paint store at the time advised that we apply (a) wood preservative, which we did. Two coats were applied two years apart. Now one side of the house is almost black while another side is pinkish gray or gray. Protected wood areas have turned an attractive darkish red. After I sanded one side, the wood surface came out a yellowish brown. Local paint stores have conflicting ideas on what to do to recover the original redwood color. What do you say? We'd like to restore the original redwood color and maintain it. Carl Lande Lawrence, Kan.

We called for help from our usual paint expert, Donald Boysen of Frazee Paint & Wallcoverings, PO Box 2471, San Diego, Calif. 92112 - (619) 276-9500. Here are his comments:

''The side that is black is a cause for worry, as it may be mildew. If so, wash it down with a mixture of one gallon of warm water, one cup of household bleach, and a half cup of trisodium phosphate (TSP).

''Scrub the surface, allow it to stand for 15 minutes, and then rinse with clear water with garden-hose pressure. Sanding all surfaces is certainly ideal.

''We manufacture a product called Creative Exterior Wood Finish. This is a linseed-oil-based, semi-transparent stain in four colors. It is a brand-new formulation and is exactly the type of product that Mr. Lande needs. The closest distributor is Andrew Inc., 2136 East Douglas, Wichita, Kan. 67214 - (316) 267- 3329. If the company doesn't have our product by the time Mr. Lande is ready to paint, it'll have a suitable offset.''

Reputable and seasoned paint and stain manufacturers have their own materials to deal with problems of redwood discoloration after the fact. I suggest you consult with a direct manufacturer's representative if local paint dealers are less well-informed on the subject.

Try a recommended material over a small, inconspicuous area before proceeding with the entire redwood siding.

You can discuss follow-up maintenance with a representative of the manufacturer of the material used.

Q. Our 25-year-old home uses wall-mounted radiant electric heaters with glass reflectors. The manufacturer no longer makes these heaters. Two units have broken glass faces which need replacement. Where can I find such glass? Alfred H. Zeidler Austin, Texas

In the absence of the manufacturer's stock glass replacement, get in touch with a local glass store concerning either tempered or Pyrex glass.

The latter is made by PPG. We are told that Pyrex is a rather recent addition to the tempered-glass idea.

Either replacement would have to be custom-made and -drilled for attachment.

To the real estate editor:

We eliminated the grate in our Franklin fireplace. Now we place one log (split side out) against the back wall, add 3 to 4 dollops of kerosene-soaked sawdust kept especially for the purpose, light it, and place a second log (split side in) against the first log.

A third (smaller) log can be placed on top of the first two for better draft.

We use no kindling and no paper. Just sawdust and an initial forced draft will ignite the most obdurate (dry) firewood and result in a roaring fire within minutes. Gordon MacIntosh Thornton, N.H.