October 10, 1918 



A Mill Scale Study of Oak 



The government Forest I'roduots Laboratory at Ma.lisoii, Wis., 

 has completed the data of a mill scale study of white and red oak 

 at the mill of George C. Brown & Co., Proctor, Ark. The study 

 wa.s made in 191.5 by David G. White, and the information procured 

 is especially appropriate now in view of the importance of wood in 

 the war. The figures are three years old, but that is an advantage 

 rather than a drawback, because they deal with normal price and 

 usual times, and not with operations carried on under extraordinary 

 conditions due to war. 



The study included white oak and red oak; the white oak con- 

 sisting of 160 logs of overcup and cow oak, the red oak of 133 logs 

 of southern red and Spanish. These logs were sawed into lumber 

 of the following dimensions: 91 per cent was 1, 1%, and 1% inch 

 lumber; 4% per cent was 2 and 3 inch stock; and 4% per cent 

 of cross ties and small timbers. 



The lumber was graded according to the rules of both the National 

 Hardwood Lumber Association and the Hardwood Manufacturers' 

 Association. The same lumber was inspected twice, the second time 

 after three months of air seasoning, but two inspections were com- 

 pared, and the results form part of the report. The first inspection 

 was made on the sorting chains at the mill, the second when the 

 piles were taken down. 



The first inspection by the Hardwood Manufacturers' rules gave 

 a total of 110,995 feet; by the National Hardwood Lumber Associa- 

 tion, 111,247 feet. The second inspection which was of the air-dry 

 lumber, gave 107,709 feet by the Manufacturers' rules, and 106,973 

 feet by the National. 



The study was planned with the expectation that it would show 

 a number of things relating to the production and care of lumber, 

 among such being the grades and the proportion of each and their 

 origin in logs of different kinds; the cost of stumpage, logging, 

 manufacturing, yarding, and general; the losses due to seasoning, 

 and other causes; changes in value during seasoning; waste due to 

 milling and other causes. 



The report by Mr. White presents tables and diagrams which gives 

 details as well as totals of all the topics which are worked out; but 

 in the space which can be here given to this review it is not prac- 

 ticable to quote the tables, but an outline of the principal results 

 is shown. 



SuMM.\RY OF Conclusions 

 The prices used in the discussion and conclusions follow: 



Quarter 

 White oak— Plain sawed 



Firsts and seconds $45 $68 



No. 1 common ; 22 36 



No. 2 common 12 20 



No. 3 common 6 fi 



No. 4 common 4 4 



Red oak — 



Firsts and seconds :....' 46 58 



No. 1 common 22 35 



No. 2 common 12 20 



No. 3 common 6 6 



No. 4 common 4 4 



Stumpage value of $5 per 1000, Doyle scale was placed on both 

 white and red oak. 



Logging cost was $6.01, consisting of $4.50 for delivering logs to 

 the railroad and $1.51 for delivery at the mill yard. 



Manufacturing cost per 1,000 net lumber tally varies with the 

 sizes of logs, but showing an average of $1.70. 



Yarding cost from the mill to the piles and then from the piles 

 to f. o. b. cars, $1.49. 



General costs, consisting of taxes, depreciation, advertising, in- 

 surance, rent and several other items, $2.64. 



Financial expenses, consisting of interest and discount, $0.65. 

 The losses in footage during seasoning has been figured out on 

 the percentage basis, and the calculations are complicated, due to 

 the fact that account is taken of green lumber, that which is tem- 

 porarily air dry, and the final air-dry; and also to the fact that two 



rules of inspection are considered. The percoiitages run differently 

 for white oak and red oak, the former loss running from 1.6 per 

 cent to 3.3; the red oak loss running from 2.8 to 9 per cent. Changes 

 in value during seasoning were not all loss. In some instances a 

 decided increase was shown. Most of the depreciation in the value of 

 white oak appeared in the lumber cut from defective logs. 



The waste in manufacturing logs into lumber, not including 

 shrinkage in seasoning and the edging and trimming after season- 

 ing, averaged for white oak logs 41.7 per cent, and for the red oak 

 29.9 per cent. 



Percentage op Grades 

 The percentage of grades for both white and red oak logs, under 

 the inspection of the two associations were as follows: 



H. M. .\. X ILL. A. 



Firsts and seconds 20.9 17.9 



No. 1 common 46.9 46.5 



No. 2 common 13 16.9 



No. 3 common 17.1 18.7 



No. 4 common 2.1 



The footage loss in seasoning, between the green and the tem- 

 porary dry condition, due to shrinkage and degrading below a 

 recognized grade, was as follows in per cent, according to the 

 grading by the two associations: 



Red oak 2.S 4.7 



White oak 1.6 2.5 



The footage loss in seasoning between the green and Jinal dry 

 condition was: 



H. M. A. N. H. L. A. 



Red oak 3.4 5.7 



White oak 2.4 3.3 



The oak study for the year 1915 shows that the profit per hour 

 for the final air-dry condition was more than for the temporary 

 air-dry condition for all classes of logs, according to inspection rules 

 of both associations. 



For all classes of logs, the profit per hour for the lumber inspected, 

 both green and dry, was greater under the rules of the Hardwood 

 Manufacturers' Association than under the National Hardwood 

 Lumber Association, except from the lumber inspected green from 

 the sound red oak butt logs. In that case the difference was very 

 small and was due to the larger amount of firsts and seconds recorded 

 by the National inspector for this one class of logs when inspecting 

 the lumber in the green condition. 



The profits per hour for the temporary air-dry condition was less 

 than for the lumber inspected green for all classes of logs, accord- 

 ing to the rules of both hardwood associations, except where plain 

 sawed sound oak logs were considered by the National inspector. 

 In this case the inspector recorded a very small per cent more of 

 No. 2 common and better for the temporary air-dry condition than 

 for the green, which reversed the amount of profit per hour for the 

 temporary air-dry and green condition. 



In the majority of cases, for the different classes of logs, the 

 profit per hour was more for the lumber in the first air-dry condi- 

 tion than in the green. This shows the wisdom of maintaining a 

 yard resaw and trimmer, since the profit should be less in every 

 case for the final air-dry condition than for the green, if the edging 

 and trimming have been perfect in the mill, and if the same selling 

 prices are used in computing the profits per hour. 



The profit per thousand was greater for the white than for the 

 red oak, because of the higher price of quartered material. The 

 profit per hour, however, was greater for the red oak, because of 

 the increased rate of production in plain sawing. 



The milling waste for all white and red oak logs was 35.S per 

 cent. The waste was 46.7 per cent and 29.9 per cent for white and 

 red oak respectively. 



Green wood may lose more than one-half of its weight in the 

 process of seasoning. In practice no such thing as absolutely dry 

 wood is known. Well seasoned lumber contains about ten per cent 

 of its weight in water. 



