98 WOODWORKING 



to close the pores, but not to fill the cells or larger holes and 

 openings. Paint, on the other hand, covers the entire sur- 

 face of the wood and, consequently, fills all openings both 

 pores and cells, as well as such artificial openings as cracks 

 and checks. It must be evident, therefore, that for exposed 

 woodwork, paint is the most satisfactory physical preserva- 

 tive covering. However, besides the fact that it obliterates 

 the material appearance of the wood, it has the possible dis- 

 advantage of checking and peeling. On the other hand, 

 when a stain has some inherent preserving quality, chemical 

 or otherwise, it results in both protecting the wood and pre- 

 serving its natural beauty. 



82. ; Classification of Wood Finishes. 



A. Non-covering agents may be divided as follows: 



1. Oil. 



2. Wax. 



3. Stain 



a. Water. 

 6. Oil. 



c. Chemical. 



d. Creosote. 



B. Covering agents may be divided as follows: 



1. Shellac 



a. White. 



b. Orange. 



2. Varnish 



3. Filler. 



4. Paint. 



83. Oil Stain is used on work which does not require a 

 high finish, but which, to present the full effect of the natural 



