Stripping old paint finishes

Press, 18 January 1979, Page 15

Stripping old paint finishes

When an old painted surface is solid and in good condition, the usual procedure is to clean off any dirt or grime, rub down lightly with fine abrasive paper and repaint.

There are times, however, when there is no alternative to stripping off the old finish and starting again from the bare timber.

Chipped and blistered finishes cannot be made good, and no matter how carefully we try smoothing around the patches, if we paint over them they are almost certain to show through as ugly scars. Similarly, it is not satisfactory trying to strip an isolated area — once we have decided that stripping is necessary go over the complete surface. Exterior woodwork may be stripped cleanly with a blowlamp and scraper. This job must be done with extreme care, first to avoid damage to the timber through scorching. Modern butane gas blow-torches are much cleaner and more convenient to use than the old paraffin type with its broad flame.

The gas type allows adjustment of the flame to suit the work being done. So far as the handyman is concerned, the most convenient way of stripping old paint or varnish is to use the various liquids available.

They are merely brushed on and allowed to

react on the old finish so that it can be scraped off. The same sort of strippers are available in pressured spray packs and are merely sprayed on. Both types are convenient to use but tend to be rather expensive if large areas are to be treated.

These strippers do not remove the actual colour from, say, a stained and varnished surface as many horn e-workers imagine they should. In other words, they are not a bleaching agent. What they do is remove the surface finish of varnish or paint, although with paint they usually clean sufficiently to reveal the natural colour of the timber.

Softening occurs almost immediately the solution is applied, but it is a mistake to start scraping too soon. Wait a few minutes until the paint “bubbles up,” when the scraper should slide through easily, right down to the bare timber. On a vertical surface scraping should start from the top and where this is possible in horizontal strokes. The scrapings should be caught on old newspaper and not left lying around. Finally the exposed woodwork should be sponged down with water, preferably hot and containing a little household detergent. Obviosly, the wood must be allowed to dry out thoroughly before starting to repaint.