230 PAINT TECHNOLOGY AND TESTS 



yellow pine, the posts being set deeply in the ground and prop- 

 erly braced. The framework of the fence was open, with a ledge 

 upon the lateral girders, upon which the plates might rest, and 

 to which the plates were secured by the use of steel buttons. 

 After the framework had been erected, painted, and made ready 

 for the placement of the panels, a small shed was built upon the 

 ground, and the materials for the field test placed therein. The 

 steel plates were unpacked from the boxes in which they were 

 shipped, brushed off, and stacked up ready for painting. Small 

 benches were erected, and the accessories of the work, such as 

 cans, brushes, pots, balances, etc., were placed in position. 



Methods Followed in Painting Plates. A frame resting upon 

 the workbench served to hold the plates in a lateral position 

 while being painted, room being allowed beneath the plate for 

 the operator to place his hands in order to lift the plates from 

 the under surface after the painting had been finished. 



A pickled plate having been placed upon the framework 

 everything was in readiness for the work. The specific gravity 

 and weight per gallon of the paint to be applied was determined, 

 and the amount, in grams, to be applied to each individual panel 

 was calculated according to the following formula: 



Spreading rate Sq. ft. in plate Grams paint in gal. 



900 sq.ft. : 6 :: 4500 : x 



The reciprocal of x being the number of grams of paint to be 

 applied to the panels. 



An enamel cup was then filled with the paint and a brush 

 well stirred within. The cup, paint, and brush were placed 

 upon the balances and accurately weighed in grams. After 

 most of the paint had been applied to the panel, cross-brushing of 

 the panel was continued until the pot with brush and paint 

 exactly counterbalanced the deducted weight. The painted 

 panel was then set in a rack, in a horizontal position to dry. 



A period of eight days elapsed between the drying of each 

 coat. The greatest care was taken in the painting of the edges 

 of the plates, and the racks for containing the plates after they 

 were painted were so constructed that the paint would not be 

 abraded while sliding the plates back and forth. The working 

 properties of each paint, and the appearance of the surface of 

 each plate after painting, were carefully noted and included in 



