136 PAINT TECHNOLOGY AND TESTS 



" Condition of Cypress. Cypress showed inferior conditions, 

 except that it was more pronounced and more discoloration of 

 the panels was noticed on this grade of wood, which seems to be 

 extremely greasy in nature and difficult to properly prime, even 

 when the paint used upon this wood contains a large percentage 

 of volatile diluent. 



" Removal of Lithopone Panels. The Joint Committees con- 

 firmed the previous recommendation to remove all the lithopone 

 formulas, and they decided to remove the cypress and the yellow 

 pine panels in every formula except in the white paints. 



" It was decided to reassemble all the white pine panels and 

 group them together for purposes of comparison, and in place 

 of the panels condemned and removed, to substitute a series of 

 new formulas, to further widen the scope of the tests. 



" Ultimate Value of Mixed Paints. The results of the inspec- 

 tion conclusively show that a mixture of more than one prime 

 white pigment, whether this mixture be alone or in combination 

 with a small percentage of inert pigment, produces a paint far 

 superior to a paint manufactured from one pigment alone. 



" As a general statement of the comparative wearing of the 

 paints, it might be said that the composite formulas are less 

 advanced toward destruction than the paints made from single 

 pigments such as lithopones, white leads and zinc oxides. It 

 is not to be understood from this statement that it is the opinion 

 of the committee that all of the composite formulas are of 

 equal value or that all of them are to be recommended, but it 

 is meant that the higher types, as evidenced by the appearance 

 of the panels, are in the above relation to the single pigment 

 paints. 



" Lithopone Destroyed Rapidly at Pittsburg. It was evident 

 some time ago that the formulas containing large percentages 

 of lithopone were rapidly failing, and their appearance was very 

 much the same as those formulas of a similar type at Atlantic 

 City. There seems, however, to be some difference in the way 

 these formulas broke down; those on the Pittsburg Fence having 

 shown the quicker destruction, possibly due to the action of the 

 acid gases in the air upon the paint coating. This further con- 

 firms the statement that paint compositions containing such 

 heavy percentages of lithopone and intended for outside use 



