Cypress & How To Finish It
How to finish cypress wood and information on the types and characteristics of cypress.
¶ A most enduring wood-and one which is being used rather extensively for clapboard siding on building exteriors, for sash, doors, floors and many other purposes where the ability to stand up against moisture and the weather generally is especially desired. It is only the brown heartwood which shows remarkable durability when subjected to conditions favoring decay. Cypress is a close, straight grained, soft wood, although its winter growth wood is quite hard. The texture of grain is rather fine. Not a strong wood. It does not swell or shrink, once well seasoned. The heartwood of the tree is rather a dark brown, while the sapwood is a yellowish white.
¶ This tree grows in swamps and when the wood is green and before seasoning it is very heavy, being filled with water and an oily sap. When correctly seasoned cypress is very light in weight. A very durable wood even in service where it is damp and where conditions are right to promote decay in other woods. It has no resin ducts and is not resinous or pitchy like hard yellow pine. It does contain considerable oily sap which is a compound having antiseptic properties and which imparts a waxy feel to the finished lumber. It is this sap which no doubt resists decay in the wood when subjected to moisture. This oil should be wiped off before painting or staining or varnishing cypress. A cloth soaked with benzine or benzole will remove the surface oil. Wipe it immediately before painting or staining. The oil will rise to the surface again.
¶ Cypress weatherboards, clapboard siding and similar cuts show great contrasts of color, When used for interior trim or for any purpose requiring a fairly uniform color in natural finish, cypress must be selected to gain some uniformity of color, the variations of color between the nearly white sapwood and dark brown heartwood are great. Penetrating stains will even up the color differences, as a rule, however. Oil stains should contain about two parts linseed oil, one part turpentine and one part benzole.
¶ In dry kilns cypress acts badly and so most of it is seasoned by air drying. When well seasoned it doesn't shrink abnormally, nor does it swell and warp in the presence of moisture.
¶ The painting of cypress while not difficult requires a bit of special knowledge and understanding of the nature of the wood. Because of the oily sap which permeates the wood, oil paint doesn't penetrate and gain sufficient anchorage unless mixed properly. The priming coat only of paint for cypress should be mixed to contain about 40 per cent of benzole (160 degrees solvent naphtha), 10 per cent turpentine and 50 per cent linseed oil. That would make your formula read about like this:
¶ 100 lbs. white lead,
¶ Benzole is one of the greatest penetrating solvents of resin, gums, grease, etc. It cuts into the oily sap of cypress and the gum resin of hard yellow pine, aids the paint pigment and oil to penetrate and gain anchorage and then the benzole evaporates completely. Benzole works about like turpentine in the paint, evaporates about as quickly and is very inflammable. Great care must be taken to keep fire away from it. The paint must be well brushed in and out.
¶ Benzole must never be used in any except the priming coats of paint. If used in a second or third coat it will soften up the under coats of paint.
¶ Benzole is a coal tar naphtha, a by-product of gas works by distillation from gas tar. It is waterwhite and will freeze solid in low temperatures. It is sometimes used to rough-up old varnish coats which are to be painted over. A coat of benzole brushed on saves rubbing with sandpaper before painting. Benzole looks like benzine but has a decidedly different odor.
¶ Cypress makes a good foundation for enamel and interior paint finishes after wiping off the oil on the surface and after mixing your first coat of paint with little oil and much turpentine and benzole. The wood being dark in color, having strong grain figures in places and strong contrasts between sap and heartwood requires an extra coat of white and colored paints to hide the dark surface. Also the grain growth is of a circling nature in places; it seems to curl up and sometimes requires more coats of paint to give a smooth level finish. Much of this roughness can be removed by sandpapering.
¶ In the stained finishes penetrating oil stain is much used. Spirit stain is satisfactory and water stain may be used with excellent results, especially when used hot and with some alcohol in it to help secure penetration.
¶ Selected and matched grain woods of cypress make very fine finishes to represent mahogany in red and brown; likewise it makes good walnut and takes all brown stains beautifully. It is practically impossible to produce a gray stain on cypress with oil stains and, in fact, any stain is quite ineffective in producing gray on this wood because of its naturally dark color. The so-called penetrating acid stains serve best on this wood for gray finishes.
¶ When selected for grain figure cypress finishes tip beautifully in its natural reddish brown color. It requires no filler. Simply wipe off the oil, make the surface smooth and clean and then shellac, varnish and rub or wax, or use flat varnish.
¶ The lacy grain of cypress finishes up with a remarkable effect in what is called the Sugied Cypress. The wood is burned over some with the flame of a blow torch which burns the soft parts but not the hard. A soft wire brush is then used to remove the charcoal resulting between the hard streaks of wood. When clean the wood is given a filler or toner coat which lodges in the depressions burned out and gives a contrast to the darker ridges of grain figure. White shellac and wax or flat varnish are then used to finish the surface. This interesting finish cannot be duplicated with any other wood.
Next Page: American Black Walnut.
This is Cypress & How To Finish.
www.craftsman-style.info is Copyright © 2005-12 by International Styles