104 BULLETIN 1036, U. S. DEPABTMENT OF AGBICULTUBE. 



Table 36. — Specifications for coal-tar creosotes. 



[All creosotes listed must be a distillate of coal-gas or coke-oven tar, and, in addition, must fulfill these 



requirements.] 



Requirement. 



Specification. 



No. 1. 



No. 2. 



Moisture content N. M. 3 p. ct.i. 



Insoluble in benzol N. M. 0.5 p. ct. 



Specific gravity at 3S° C. referred to 

 water at 15..5* C ' N. L. 1.03 2 



Distillates up to 210° C 



Distillates up to 235° C 



Specific gravity of fractions at 38° C. 

 referred to water at 15.5° C: 



Fraction 235° to 31 5° C 



Fraction 315° to 355° C 



The float test must not exceed 50 sec- 

 onds at 70° C. if the residue at 355° C. 

 exceeds 5 p. ct 



Coke residue N. M. 2p. ct.. 



N. M. 5p. ct. 

 N.M. 25p.et 



N. L. 1.03... 

 N. L. 1.10... 



N.M. 3p.ct.. 

 N. M. 5 p. ct. . 



N. L. 1.03 



N.M.Sp.ct.. 

 N.M. 35 p. ct. 



N. L. 1.03. 

 N. L. 1.10. 



5p. ct 



N.M. 2p. ct. 



No. 3. 



N. M. 3p.et.. 

 N. M. op. ct.. 



N. L. 1.03 



N. M. lOp. ct. 

 N. M. 40p. ct. 



N.L. 1.03.... 

 N. L. 1.10.... 



5 p. ct 



N. M. 2p. ct.. 



No. 4. 



N.M.Sp.ct. 

 N. M. op. ct. 



N. L. 1.06. 



N. M. 5 p. ct. 

 N. M. 15 p. ct. 



N. L. 1.03. 

 N. L. 1.10. 



5 p. ct. 



N. M. 2p.ct. 



.Specification No. 1= Grade 1, A. R. E. A.: creosote for ties and structural timber of A. "W. P. A. 



Specification No. 2= Grade 2, A. R. E. A. 



Specification No. 3= Grade 3, A. R. E. A. 



Specification No. 4= Distillate oil for paving blocks, A. W. P. A. and A. S. M. I. 



1 N. M.= Not more than. 

 2 N. L.= Not less than. 



Table 37. — Specifications for coal-tar solutions. 



Requirements. 



Composition of solution 



Water content 



Insoluble in benzol 



Specific gravity at 3S° C. referred to water 



atl5.5°C 



Distillates up to 210° C 



Distillates up to 235° C 



Specific gravity of fractions at 38° C. referred 



to water at 15.5° C: 



Fraction 235° to 315 C 



Fraction 315° to 355° C 



Float test must not exceed 50 seconds at 



70° C. if the distillation residue at 355° C. 



exceeds 



Coke residue 



Specification No. 1. 



Specification No. 2. 



80 per cent distillate of coal- : 65 per cent distillate of coal- 

 gas or coke-oven tar; 20 1 gas or coke-oven tar; 35 

 per cent filtered or refined i per cent filtered or refined 

 coal-gas or coke-oven tar. j coal-gas or coke-oven tar. 



N. M. 3 per cent 1 N. M. 3 per cent. 



N. M. 2 per cent ; N. M. 2 per cent. 



/N. L. 1.032 ...[ N. L. 1.03. 



tN. M. 1.12 1 N.M. 1.14. 



N. M. 5 per cent | N. M. 6 per cent. 



N. M. 25 per cent ; N. M. 25 per cent. 



N.L. 1.03. 

 N.L. 1.10. 



26 per cent 



N. M. 6 percent. 



N. L. 1.03. 

 N. L. 1.10. 



35 per cent. 



N. M. 10 per cent. 



Specification No. l=Tar solution for ties and structural timber of A. R. E. A. and A. W. P. A. 

 Specification No. 2= Tar solution for paving blocks of A. W. P. A. and A. S. M. I. 



1 N. M.= Not more than. 



2 N. L.= Not less than. 



WATER-GAS TAR. 



Up to the present time no specifications have been adopted for 

 either water-gas tar or water-gas-tar creosotes to be used alone as a 

 wood preservative. The American Railway Engineering Association 

 adopted in 1920 a specification for water-gas tar distillate and a spec- 

 ification for water-gas tar solution to be used in conjunction with 

 zinc chloride by any of the preserving processes employing both zinc 

 chloride and oil. The requirements of these specifications are given 

 in Table 38. 



