MILL INSPECTION OF STRUCTURAL STEEL. 517 



not. It is probably best to paint the metal if it is not to be imbedded at once, or is not to be used 

 inconcrvti'-Mrrl confirm -limi where the adhesion of tin- ci-nu-nt to the metal is an essential element. 

 When tin- mrt.il i-- to l>r imbedded immediately it is better not to paint it. 



Portland Cement Paint. A Portland cement paint has been used on the High St. viaduct in 

 Columbus, Ohio, with K"" ( ' results. The viaduct was exposed to the fumes and blasts from 

 locomotives, so that an ordinary paint did not last more than six months even on the least exposed 

 portion^. I'lu- method of mixing and applying the paint is described in Engineering News, 

 April ->4tlt aii.1 J inn- 51 h, 1902, as follows: " The surface of the metal was thoroughly cleaned with 

 win- 1 IRISH'S and files the bridge had been cleaned with a sand blast the previous year. A thick 

 coat of Japan drier was then applied and before it had time to dry a coating was applied as fol- 

 lo\\s: Apply with a trowel to the minimum thickness of A in. and a maximum thickness of 

 i in. (in extreme cases i in.) a mixture of 32 Ib. Portland cement, 12 Ib. dry finely ground lead, 4 

 to 6 Ib. boiled linseed oil, 2 to 3 Ib. Japan drier." After a period of about two years the coating 

 was in almost perfect condition and the metal under the coating was as clean as when painted. 

 The cost of the coating including the hand cleaning, materials and labor was 8 cts. per sq. ft. 



INSTRUCTIONS FOR THE MILL INSPECTION OF STRUCTURAL STEEL.* 



(1) Study the contract and specifications and secure such information concerning the pro- 

 posed structure as will permit a full understanding of the use to be made of the various items of the 

 order. 



(2) Secure copies of the mill orders, shipping directions and other information concerning the 

 material to be inspected. 



(3) Attend promptly when notified of the rolling of material and so conduct the inspection 

 and tests as not to interfere unnecessarily with the operations of the mill. 



(4) Have the test specimens prepared and properly stamped with the melt numbers by the 

 manufacturer. Observe the selection and stamping of specimens and verify the melt numbers 

 when practicable. 



(5) Attend and supervise the making of tensile, bending and drifting tests. Make sure that 

 the testing machines are properly handled and that the specified speed of pulling is not exceeded. 

 Note the behavior of the metal and check and record the results of the tests. 



(6) Select the bars or other members for full-size tests as specified. Supervise such tests 

 and check and record their results. 



(7) Secure from the manufacturer records of the chemical analyses of the melts and accept 

 only those in which the specified contents of impurities are not exceeded. 



(8) Secure pieces of the test ingots and test specimens and have check analyses made outside 

 of the manufacturers' laboratory when the analyses furnished by the manufacturer are erratic or 

 for any other reason appear to be incorrect. 



(9) Examine each piece of finished material for surface defects before shipment, requiring 

 the material to be handled in a manner that will permit the examination to be thorough and 

 complete. This inspection should detect evidence of excessive gagging or other injury due to 

 cold straightening. 



. (10) Report promptly the shipment of any material from the mill, whose surface inspection 

 has been waived. Such material should be examined by the shop inspector, 

 (n) Verify the section of all material by measurement and by weight. 



(12) Study the operations of the plant and become familiar with the various processes of 

 manufacture. 



Cultivate the acquaintance of the mill employees and become familiar with their work so as 

 to have direct knowledge of the mill practice and determine as well as the circumstances permit 

 the correctness of the mill practice in so far as it is covered by the specifications. 



(13) Record all tests and analyses on the forms provided. 



(14) Keep informed as to the progress of the work in the shop and endeavor to secure the 

 shipment of material at such times and in such order as to avoid delay in the fabrication. 



(15) Secure copies of the shipping lists and compare them with the orders and make regular 

 statements of the material that has been rolled and shipped. 



(16) Make reports weekly or as may be directed, submitting complete records of tests, 

 analyses and shipments and such other information as may be required. 



* American Railway Engineering Association, Adopted, Vol. 14, 1913. 



