Applying A Semi-Transparent Or Opaque Stain To Wood

Historic Preservation

Building Manager Tools

Historic Buildings

Historic Preservation Library

Portfolio Management Resources

Preservation Desk Guide

Preserve America

Project Management Tools

Realty Specialist Tools

Technical Resources

GSA Technical Preservation Guidelines

Historic Preservation Technical Procedures

NCR Preservation Note Series

Preservation Technology

Historic Preservation - Technical Procedures

Spectitle:	Applying A Semi-Transparent Or Opaque Stain To Wood
Procedure code:	0630003R
Source:	Developed For Hspg (Nps - Sero)
Division:	Wood And Plastics
Section:	Wood Treatment
Last Modified:	02/24/2012
Details:	Applying A Semi-Transparent Or Opaque Stain To Wood APPLYING A SEMI-TRANSPARENT OR OPAQUE STAIN TO WOOD PART 1---GENERAL 1.01 SUMMARY A. This procedure includes guidance on applying a semi- transparent or opaque stain to wood surfaces. This coating will prolong the service life of wood and provide some protection against agents of deteri= oration. NOTE: IF THE WOOD WAS ORIGINALLY FINISHED WITH A FULL BODY PAINT, IT SHOULD BE REPAINTED RATHER THAN STAINED, AS THE VISUAL APPEARANCE OF STAIN IS NOT COMPATIBLE WITH THAT OF PAINT. SOME STAINS, HOWEVE= R, MAY BE SUITABLE REPLACEMENTS FOR WHITEWASH PAINT. = CONSULT THE RHPO FOR GUIDANCE AND RECOMMENDATIONS. B. Natural causes of wood deterioration include decay= , ultraviolet degradation, insect infestat= ion and excess moisture. C. Some types of problems resulting from the weatheri= ng process include: 1. Fungi and/or mildew growth 2. Warped boards 3. Loose fasteners 4. Changes in surface texture resulting in cracks and checks D. In addition to opaque paints, various so-called "natural" finishes and colored stains provide this necessary protection. And, like paints, proper surface preparation and application are vital to long lasting protection. E. See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections: 1. Safety Precautions 2. Historic Structures Precaution= s 3. Submittals 4. Quality Assurance 5. Delivery, Storage and Handling= 6. Project/Site Conditions 7. Sequencing and Scheduling 8. General Protection (Surface and Surrounding) These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO). 1.02 DEFINITIONS A. Semi-transparent Penetrating Stains: Thin, moderately pigmented water repellents and water repellent preservatives which penetrate the wood allowing the natural grain and texture to show throug= h. 1. The addition of the pigment protects the wood against ultraviolet degra= dation and increases the durability of the finish.= 2. Semi-transparent penetrating stains made from water repellent preservatives (WRP's) are recommended: a. They provide additional protection against decay= . b. They penetrate the wood rather than forming a film they will not peel, flake or blister. B. Solid Color (Opaque) Stains: Provide an opaque finish with a slightly lower concentration of pigment than regular paints. They result in a flat finish which hides the natural color and grain of the wood but maintain the original texture. Available in both an oil-based or latex-based product, solid color stains form a thin film on the surface of the wood and are there= fore subject to peeling, flaking, etc., just as paint is. 1.03 DELIVERY, STORAGE AND HANDLING A. Storage and Protection: Stains shall be in sealed containers that legibly show the designa= ted name, formula or specification number, batch number, color, quantity, date of manufacture, manufacturer's formulation number, manufacturer's directions including any warnings and special precautions and name of manufact= urer. Stains shall be stored on the project site and shall be stored to prevent freezing. They shall be kept covered and safeguards taken to prevent fire. 1.04 PROJECT/SITE CONDITIONS A. Environmental Requirements: 1. Unless otherwise recommended by the manufacturer, the ambient temperature shall be between 50 degrees F. and 95 degrees F. when applying either a stain or WRP. 2. Do not apply when the relative humidity exceeds 85% or the moisture content of the wood exceeds 12% as measured by an electronic moisture meter. 3. Do not apply a stain in the direct sun. They shall be applied only when the surface to be treated is in the shade and the sun is shining on the opposite elevation. The west elevation should be treated in the morning when the sun is shining on the east elevation; the north elevation should be treated around noon when the sun is shining on the south elevation; the east eleva= tion should be treated in the afternoon when the sun is shining on the west elevation; and the south elevation should be treated late in the after= noon when it is in full shade. 4. Do not apply stains to damp surfaces, in misty or rainy weather, in the snow or where there is visible ice or frost on the surfaces. 5. For optimal results when using a latex stain do not apply when the temperature is expected to go below 50=F8 F. within 24 hours of application. On hot, dry days, to prevent the stain from drying too quickly, the surface can be slight= ly dampened before the application of a latex stain. Be sure to follow all manufacturer's instru= ctions. 1.05 MAINTENANCE A. Semi-transparent Penetrating Oil-based Stains Finish: 1. The life expectancy of these stains varies tremendously depending on whether one coat or two coats of stain were appli= ed initially. a. A single coat, applied to smooth wood should last 2 to 4 years. b. A two coat system, however, should last up to 8 years depending on the exposure. Coastal expos= ures or cold environments especially at high altitudes will deteriorate more quickly, as will most southern exposures. A loss of color is a good indication that the finish must be renewed. 2. Clean surfaces with a stiff, nonferrous bristle brush to remove dirt and loose wood fibers. 3. If the surface has mildewed, wash with bleach and detergent, rinse and let dry completely before applying a new coat of stain. NOTE: Because of the more porous nature of weathered wood and the better penetration of stain that results, subsequent applications will last somewh= at longer than the initial application. PART 2---PRODUCTS 2.01 MANUFACTURERS A. The Sherwin-Williams Co. 101 Prospect Ave. NW Cleveland, OH 44101 216/566-2000 B. Olympic Stain 2233 112th Avenue, NE Bellevue, WA 98004 800/426-6306 or 206/453-1700 C. Samuel Cabot, Inc. 100 Hale Street Newburyport, MA 01950 508/465-1900 D. Rez Finishes (Division of PPG) One Gateway Center Pittsburgh, PA 15222 800/441-9695 or 412/434-3131 E. Minwax Co., Inc. 16 Cherry Street Clifton, NJ 07014 201/391-0253 F. Benjamin Moore 51 Chestnut Ridge Road Montvale, NJ 07645 201/573-9600 G. Flood Company PO Box 399 Hudson, OH 44236 800/321-3444 2.02 MATERIALS A. General: 1. Conventional spar, urethane and marine varnishes are generally not recomme= nded for exterior use. These film forming finish= es are quickly degraded by sunlight. If a long service life is not required, and the area to be varnis= hed is fully protected from the sun, varnishes can be used satisfactorily if properly applied, See Part 3 - Execution. 2. All stains shall be from the same manufacturer to avoid problems with penet= ration and coverage. Different batches of stain, even from the same manufacturer, should also be avoided for the same reasons. B. Oil modified alkyd semi-transparent penetrating stain such as "S-T Wood Preservative Stain, A14T5" (Sherwin Williams), or approved equal. Other manufacturers are listed in Section 2.01 above. 1. Oil/alkyd based semi-transpare= nt penetrating stains, which contain a wood preservative, are recommended over latex-ba= sed products. Latex-based stains do not penetrate the surface and are subject to peeling, flaking, etc. 2. These stains are most effective on rough lumber and plywood, smooth lumber, weathered wood, and flat- grained surfaces of dense species that do not hold paint well. 3. They can also be used over other penetrating finishes which have weath= ered to the point of needing to be renewed. 4. They are NOT, however, effecti= ve over paint, solid- color (opaque) stains or varnish, nor on smooth plywood. -OR- Solid color (opaque) stain such as "= ;Series A14" (Sherwin Williams), or approved equal. Other manufacturers are listed in Section 2.01 above. 1. Though both oil- and acrylic-b= ased solid colored stains are available, the acrylic-based stains are considered by the USDA's Forest Products Laboratory to be the best of the opaque stains and are recommended here. 2. If the choice has been made to use an opaque stain, their use is recommended when going from a semitransparent penetrati= ng stain or an opaque oil stain to a lighter color, to cover a previously creosoted surface, or when covering new, close- pored wood species such as Southern yellow pine. Like latex paint, acrylic= -based opaque stains are also more resistant to mildew, are easy to apply and clean-up with soap and water. 3. Oil-base opaque stains may be successfully used on fresh, clean wood but they are NOT recommended for previously painted wood, even if all of the paint has been removed. N= or are they recommended for reapplication over existi= ng oil-based opaque stains. In both cases an uneven, splotchy appearance can be the result. 4. Solid color stains, either oil- or latex-based, are NOT recommended for flat, horizontal surfaces such as window sills, handrail= s, porch floors, or decks. C. Raw linseed oil: The linseed oil shall be clean and colorless so that it will not adversely affect the texture or durability of the paint. D. Caulking compound: 1. Polyurethanes - easily workabl= e; paintable; 15-20 year life span; limited availability, see section on products and suppliers= . 2. Polysulfides - slow drying; can be sanded and painted; highly elastic; limited availability, see section on products and suppliers. 3. Butyls - paintable but cannot be sanded; 7-10 year life span. 4. Silicones - some can be painted but generally not sanded. 5. Acrylic Latex - for exterior work, their use is best left to tight, narrow joints; short life span especially when compared to polysulfides and polyurethanes. 2.03 EQUIPMENT A. Brushes: 1. Use natural bristle paint brushes for oil/alkyd stains. Precondition by soaking in raw linseed oil for 24 hours. Use nylon bristle brushes for latex stains. Do not use the same brush for both types of stain. 2. For thin, runny stains, foam pad applicators can be used. 3. Stiff natural bristle scrub brushes. PART 3---EXECUTION 3.01 PREPARATION A. Surface Preparation: Like any paint system, the surface to be treated must be clean and free of any loose, rough wood fibers, loose paint or varnish , or any mildew, grease or dust. The surface must be as meticulously prepared for a stain as it would be if it were being painted. See 06300-02-R for guidan= ce on preparing wood surfaces for recoating. 3.02 ERECTION, INSTALLATION, APPLICATION A. Mixing the Stain: 1. Mix the stain thoroughly and frequently. This is important in maintaining an even color coverage. 2. Pour off the top oils to a smaller container. Stir the remaining contents until well mixed, add back the top oils and mix thoroughly again. If possible, do all of the mixing in a larger container, i.e. use a five gallon paint to mix 2-3 gallons of stain. T= his will allow more vigorous and thorough mixing witho= ut fear of spilling. 3. When the first batch of stain is about 2/3 gone, stir the remaining stain into a new batch of stain. This will help even out any differences in color and pigment concentrations between cans. 4. Throughout the application stir the stain often to keep the pigments and oils well mixed. B. Applying a semi-transparent (oil-based) penetratin= g stain: NOTE: The application of a semi-tr= ansparent penetrating stain is best performed with a brush as it provides the best control. Stains may also be spray- or roll-applied; however, an even application is difficult to achieve using either of these methods. For stains that are especially thin, foam applicators will help control the application. 1. For dense species of wood such as Douglas Fir or Southern pine, treat the surfaces first with a water repellant preservat= ive and let the wood weather for a year before staining. See 06310-01-P for guidance. This will allow the first coat of stain to penetrate more deeply and uniformly because the surface is more porous and will result in a more durable finish.= 2. Start at the top of the area to be stained and work down, applying the stain to a small number of boards or a single panel at a time. This will help avoid lap marks. If possible, stop at a logical breaking point such as the end of an individual clapboard or at a door or window. NOTE: DO NOT LET THE FRONT EDGE DRY BEFORE BEGINNING THE NEXT SECTIO= N. a. When using a commercially available stain, follow all manufacturer's instructions. b. When using semi-transparent oil-based penet= rating stains, one gallon will cover appro= ximately 200-400 SF when applied to a smooth surface, and 100-200 SF when applied to a rough or weathered surface. 3. For rough or weathered surface= s, apply two (2) successive coats of the stain. a. Brush on the first coat of stain, again worki= ng in small, logical areas. Allow each coat to soak into the wood for 20 to 60 minut= es before applying the second coat, but do not allow the first to dry completely. b. About an hour after the application of the second coat of stain wipe off any excess stain with a cloth, sponge, or brush which has been sligh= tly dampened with the stain. 4. When used to cover an old, weathered penetrating natural finish: a. Brush with a stiff bristle brush to remove dust and loose wood fibers. NOTE: DO NOT USE FERROUS BRUSHES OR WOOLS. THESE CAN LEAVE SMALL IRON PARTICLES ON THE SURFA= CE OF THE WOOD. CERTAIN WATER-SOLUBLE EXTRA= CTIVES NATURALLY FOUND IN SOME WOODS SUCH AS WESTERN RED CEDAR, REDWOOD, DOUGLAS-FIR AND OAK CAN REACT WITH THE IRON PARTICLES CAUSING BLUE-= BLACK STAINING. PENTA= CHLOROPHENOL, A COMMON WOOD PRESERVATIVE OFTEN FOUND IN SOME WRP'S AND SEMI-TRANSPARENT PENET= RATING STAINS, CAN ALSO CAUSE LOOSE IRON PARTI= CLES TO CORRODE WHICH CAN IN TURN REACT WITH THESE SAME WATER-SOLUBLE EXTRACTIVES CAUSI= NG THE SAME BLUE-BLACK STAINING. b. After applying the new coat of stain carefully exami= ne the surface. 1) A dull, flat surface will indicate that the stain has evenly penetrated the wood. 2) A slightly glossy surface will indicate that penetration of the stain was uneven resulting in a less durable surface which will need to be renewed more often. 5. During application, if it is possible, remove any trim pieces which are to be stained a different color because it is diffi= cult to cut-in stain. For better control and more even coverage and penetration, prestain any new wood. C. Applying a solid color (opaque) stain: NOTE: Opaque stains react much the same way as do oil- based and latex paints. Brush application is the best but a roller may also be used. Fol= low the same procedures outlined for semi-transparent penetrating stains in Section 3.02 B. above. 3.03 ADJUSTING/CLEANING A. As with quality surface preparation for painted surfaces, caulking joints is an important part of surface preparation. CAULKS, however, ARE NOT STAINABLE, so caulk after staining has been complete. Also caulk after a WR or WRP has been applied. END OF SECTION

Last Reviewed 2012-02-24