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AP PLICATION OF EXTERIOR PAItfTS 



A good exterior "paint-job" begins with the selection of a correctly formu- 

 lated paint. However, even good paint will give poor service when incorrectly 

 used. Factors to be considered in the application and maintenance of exterior 

 paints include (1) the condition of the surface, (2) weather conditions at the 

 time of application, (3) the frequency and rate of application, and (4) conditions 

 which tend to increase the moisture content of the wood under the paint film. 



Condition of the Surface . Before painting make certain that the surface is clean, 

 dry, and free of chalky, peeling, scaling or blistered paint. 



Ordinary grime and chalk can be removed by scrubbing with water. Heavily 

 chalked surfaces should be cleaned Xi7ith a stiff brush. If scaling and blistering 

 has occurred, but is not severe or widespread, the loose paint should be removed 

 with a wire brush or scraper, then the surface finished by sanding with a No. 2 

 garnet paper. If scaling and blistering is extensive, removal can be done easier 

 and more effectively by using a liquid paint remover or by burning the paint off 

 with a blow torch. CAUTION : Due to the danger of setting fire to the wood under 

 the paint, the process of burning paint off should be done by a careful and 

 experienced operator. 



Weath er Gonditions. Painting should be done in the summer or fall when the tera- 

 perat'ure is between 50° and 90°F. and, if possible, out of direct sunlight. 

 Never paint during foggy, misty weather or when rain threatens. After a rain, do 

 not begin or resume painting until the surface has become thoroughly dry. Delay 

 the beginning of work in the morning until all dew has evaporated from the surface. 



How Much Paint and How Often ? For new v/ork three coats of paint are usually rec- 

 ommended. The priming coat should be thoroughly brushed on at a rate of about 

 one gallon for each 600 square feet of surface. Zinc-free primers usually give 

 better adhesion and are recommended except for use with fume resistant paints. 

 When it is necessary to do so, a primer can be made by mixing one pint of linseed 

 oil to one gallon of the finish coat paint. The addition of one pint of thinner 

 per gallon of paint will increase workability and penetration into the wood. 



The second coat may be thinned as the manufacturer recommends (usually one 

 pint of thinner per gallon) and applied at the rate of one gallon for each 700 to 

 800 square feet. 



The finish coat should be applied unthinned at a rate of one gallon for each 

 600 to 700 square feet. 



During good weather two or three days drying time should be allowed between 

 coats. It is important, however, that the time between coats be not longer than 

 one to two weeks. 



In a paint maintenance program care must be taken to prevent the build-up of 

 a thick layer of paint due to frequent applications. If a build-up occurs, it 

 will lead to a bad condition of cracking and scaling which can only be corrected 

 by the complete removal of the paint. The ideal paint maintenance program would 

 be one in which the paint is replaced at intervals as it is weathered from the 

 surface. This, however, cannot be done on a practical basis, and one of two 



