177 



CHAPTER XI 



EXPOSURE TESTS OF SPECIAL PROTECTION METHODS 



By R. C. Miller and C. L. Hill 



In addition to the experimental worlc on preservatives and methods of treatment 

 described in the foregoing chapter, this Committee undertook to make tests of various 

 woods reputed to have imusual natural resistance to borer attack, and of methods 

 for protecting wooden piling, most of which ha\'e not been in use for a long enough 

 time to make service records available. These methods are mainly, although not 

 exclusixely, of the class of paint and batten surface protections, and most of them 

 imohe materials of patented or secret composition. Their number is consideraljle, 

 and the insistence with which they are being promoted in this region creates a need 

 among users of piling for such information as can be obtained, on unprejudiced and 

 reliable authority, for the appraisal of values. 



Such tests were made usually at the request of the piroponents of the methods 

 in question. The tests have been carried out in accordance with the standard {practice 

 adopted by this Committee for its own experimental work, and every effort has been 

 put forth to insure a fair and thorough test of each sample submitted. In some cases, 

 however, the samples submitted were not suitable for testing, material of this sort 

 ranging from small pieces of shingle to irregularly shaped sections of railroad tie. 

 In a few instances, as when the tide-level testing platform at the Oakland Mole was 

 washed out by a severe storm, with everything attached to it, such samples were 

 unfortunately lost or destroyed before the test could run for an adequate time. This 

 is inevitable in such work, and the Committee's own tests suffered from the same 

 causes. 



On account of tlie limited period of inspection of these tests — a maximum of 

 slightly over 4 years — the Committee is unwilling to give to an\' of the methods 

 tested its unqualified endorsement. The results, however, as set forth in the following 

 tables, are regarded as affording a useful preliminary indication of the probable 

 success or failure of the treatments used — conclusive for the no small number which 

 failed. 



In all of the tables 25 to 27, the letter designations in the first column refer to 

 the sev'eral exposure stations, as follows: 



A = Oakland Mole. 



B = Pier No. 7, San Francisco. 



C= Crockett. 



D = Mare Island. 



