Document oMR0XbJxwm5Nz652KLBzBvDXr

/*% L- titiUiiH lii MARSHALL L KBMQBAKDDM REPORT IIOa M-W Indexed CC: D, 'McBurney,D*4iJOi6,Wilm J, . Ili.ff, .Lain R, Morgan, " P. B, .Stans, w R. B, Davis, " C, R, E, Mark!, Lai). K. C, Lamport, t! Stuart Graves, w Fllei 06.53 Marshall Laboratory June 12, 1952 KRiaici ca?v r ;lil *>,, GLOBE OTIFORMZTf OF 301-892 #40 OUTSIDE WHITS in t r o d u c t io n : The objective was to determine the gloss uniformity, or gloss variability, of 301-892 high gloss #40 outside White versus the performance of two major competitive paints. The work was undertaken 'primarily because of the Sales Department's difficulty in preparing uniform appearing demonstration panels. Information about the performance of 347-817 Bouse Primer Is also available from this work. The competitive paints used were Devos' #$4? outside White Gloss (SR-447735 and Sherwin-Williams #471 Gloss White House Paint (s r -44771)> Included as an added control was 30188$ last previous #40 0.W. * SOMMARY AND GOICLHSiOiSt 1, average Gloss The overall gloss of 301-892 is lower than SherwinWilliams, but higher than 301-88$ and Devos'a House Paint. sw? . 301-892 301-88$ Devo Over Clapboard 59.6 $2,8 36.7 33.4 Primed Pearlboard 78 78 $6 $7 2, House Primer 347-817 is deficient in gloss hold-put3 this confirms previous information. .Average gloss of all paints over 347-817 H* ** 51 self-primed 40.6 50.6, N35452 ~2- 3. Variability In Gloss a. Variability of gloss on one test area (Variability among the 8 gloss readings on the panel)? aver 347-817. 301-885 is less variable than SherwinWilliams, Sherwin-Williams' Is less variable than 301-892 and Devoe. 301-892 and Devoe are equal - the most variable paints. Self-primed and competitive paints over their respective primers. 301-885 and 3-W over S-W Primer are equal and leas vari able than Devoe self-primed. These are the only signif icant differences, 3QI-892 la between S-W and Devoe, but not significantly different from either,, b. Variability due to Topcoat Spreading Rate? Gloss of the topcoat is affected by changes in the spreading rate of the topcoat. Over 3^7-817. An increase in topcoat spreading rate from 5SS~^So~f5^sq. ft ./gal, reduces gloss of the Devoe paint . more than it reduces the gloss of 301-885 and SWP, 301892 is reduced to an intermediate degree rot significantly different from any. Self-primed and competitive paints over their respective primers, . The corresponding increase in topcoat spreading rate reduces the gloss of both 301-892 and Devce more than it reduces the gloss of 301-885 and Sherwin-Williams. Therefor, 3OI-892 and Devoe are deficient in gloss uniformity as it is affected by topcoat spreading rate. . c. Variability due to Prime Coat Spreading Hate: , kn increase from ^50 to 750 sq.ft./gal. in prime coat spreading rate has a small overall effect of reducing topcoat gloss, but does not affect one paint more or less than another. The evidence shows that 301-892 is somewhat leas foolproof in gloss uniformity than the Sherwin-Williams product and may explain r DU P030003394 3- why the Sates personnel had difficulty in preparing uniform demon stration panels. However, in view of the fact that 30}.-892 was rated satisfactory for this property in the 1951 field tests conducted by the Sales Department, we feel that the difference probably has little practical significance. Large .scale tests, covering a direct comparison between 301-892 and the SherwinWilliams product, would be needed to settle this point, PROPOSED ACTION: 1, 34-7-817 needs to be improved for hold-out; this Is now an active objective on Project F-1047. 2. Before undertaking work to improve the gloss uniformity of 301-89S, we should make large scale application tests (on houses) to determine whether the difference observed here between 301-892 and Sherwin-Williams has any practical significance, This should cover new wood and repaint, and self-priming and application over the improved primer (Paragraph l). We will bring this up for a decision at the P-1047 objective review on July 14, . 3. Close uniformity will also be considered in the present Class G work to improve application properties. DETAILS; Experimental Design; The experimental work involved the follow ing variaFIei?: 4 Topcoats over a common (347-317) primer. 4 Topcoats self-primed 2 Competitive topcoats over their respective primers 2 Topcoat spreading rates (500 and 750 sq.ft./gal.) 2 Prime coat spreading rates (450 and 750 sq.ft./gal.) 2 .Replicates - Total Determinations - $0 The above variables were designed to show differences in gloss between topcoats, effect on gloss of 347-817 House Primers versus self-priming and the effect on gloss of spreading rate of topcoat and primer coat which were used as a measure of gloss vari ability, In addition, each determination was a mean of 8 individual gloss readings on one test area. The average variability among these 8 readings was also used as a measure of gloss variability. The nonuniformity of gloss at laps as experienced in earlier products Is not evaluated in these tests. Sixty degree gloss measurements were made using the Photo Tolt gl os Blaster. For purposes of statistical analysis, all systems primed with 347-817 House Primer were treated in one problem while the selfprimed systems and the competitive paints over their own primer were treated as individual problems. DUP030003395 Edge-grained red cedar Clapboards were used as substrate for these tests. Each panel was divided in the middle to ,lve two 6" x 18" test areas. On each panel, the variable between the two test areas was prime coat spreading rate, i e. 450 sq.ft./gal. on one end and 750 sq.ft./gal. on the other. Each panel had on top coat spreading over the entire length of the panel. For the effect of primer and topcoat spreading rates, the variability was estimated by an analysis of variance using the data shown in fable I. The "between boards" variance and the error variance were calculated directly from the data. The ''between boards" variance was found not to be significant by the "F" ratio test, therefore, the two variances were combined to give the overall standard deviation of the test - 3.82 gloss units. All confidence limits shown on the attached tables are for a probability level of For the variability of individual gloss measurements on each test; area, the mean standard deviation for each system was estimated by the "Method of Ranges" described in H. B. Wagner letter dated 6/3/51 titled "A graphical Method for Analysis of Variance". The results of these tests are listed in the attached tables. The individual gloss determinations for each test area are shown in Table 1. In Table II is shown the average gloss for the particular batch of each paint, both self-primed and over primer. It will be noted here that only one batch of each product was used. The effect of batch variation on gloss uniformity has not been determined. The most obvious conclusion to be drawn from Table II Is the inferiority in glpss hold-out of the 3^7-817 House Primer, while the competitive primers are equally as good as their topcoat self-primed. The effect of topcoat spreading rate Is illustrated in Table III. The change from 500 sq.ft, per gallon to 750 sq.. ft. per gallon has a highly significant general effect on gloss level, With the exception of the system 301-88.5 self-primed this change in spreading rate has a significant effect on each individual paint system. The interaction between topcoats and topcoat spreading rate has been used as one .measure of gloss uniformity . Thus, it will be noted that, over 347-817, the Devoo paint is affected to a .signifi cantly greater extent than either 301-885 or Sherwin-Williams, and that 301-892 is intermediate, but not significantly different from hy. The pattern is the same with the self-primed systems, except that both 301-892 and Devow show a significantly larger change than 301-885 and SWP. The effect of prime coat spreading rat (Table IV) is very small and only significant where 347-817 is used In the system. Only DUP030003396 one individual paint, 301-892, shows significantly lower gloss with an increase in primer spreading rate There is no significant dif ference between topcoats in this test. . In Table V is listed the average standard deviation for each paint of the 8 individual gloss measurements which make up one determination as shown in Table I, The standard deviation is usdd as a measure of the dispersion or variability of gloss on the panel and comparisons between products are made by the "F" ratio test. In the systems over 3^7-817, it will be noted that 301-885, at least this particular batch, is most uniform, 3-W Is intermediate and 301-892 and Devoe are least uniform. Of the In dependent systems only 301-885 self-primed and. Sherwin-Williams over S-W Primer are significantly more uniform than the Devoe paint self-primed. There are no other significant differences in this group. A visual examination of the panels, without an attempt to rating them, confirms, in general, the above conclusions as drawn from the analysis of gloss measurements. The Devoe paint was easily recognized as having the least uniform glcss of all the paints and 301-892 was clearly lower and less uniform in gloss than Sherwin-Williams.. It will be noted that in the competitive products, the gloss' of Sherwin-Williams paint has Increased since the last previous evaluation and that the Devoe product has decreased In gloss. An examination of label analyses shows that the following Changes have been made which may account partially for the change In gloss levelsIn Sherwin-Williams #4-71 Gloss White, the solids has been increased and pigment volume reduced by increasing the amount of "Raw Linseed Oil" with a reduction in drier and thinner content, in Devoe4s #5^7 Outside White Gloss, TiOg has been reduced slightly with a corresponding Increase in calcium carbonate extender and the vehicle now contains 11$ (of total liquid vehicle) of "Processed Castor Oil." References; Experimental data are located In Notebook #3850 page l6l and Notebook #5^57 pages 14 through 16. Statistical calculations are located in Notebook #5^57 pages 56 through 72. MARSHALL LABORATORY j e o ?lm 6/11/52 DUP030003397 7ABLB 1 IMDIVIDUAL GLOSS DETERMINATIONS Over 347-317 450 75O SelfPrimed 450 750 Over Devoe Primer 450 750 Over SWP Primer 450 750 301-892 500 750 56.0 58.9 45.6 41.0 46.6 54.8 46.9 30.8 301-885 Devoe Skip 500 36.6 36.5 750 32.1 27.4 500 42.0 39.6 750 22.1 21,1 J5So*0*am0*m 750 61.8 47.9 61.3 49.6 35.4 35.4 22,8 45.0 19.9 54.9 46,0 25.3 32.1 16,8 57.8 50.6 62.8 65.5 70.9 64.0 57.4 45.5 48.8 50.6 46.3 47.1 44.3 39.6 38.4 44.9 29.6 68,5 57.1 41,1 48.3 28.5 72,0 64.9 39.6 44.8 .2S.1 66.3. 61 ,B 38.8 46.0 28.7 8 64.6 44.6 25.6 48.0 28.9 45.9 23.6 38.5 31.8 71.1 60.8 6r.3 65.9 70.1 63.9 66.5 59.6 Each determination a meat) of 8 gloss measurements. DUP030003398 TABLE XI MEAN GLOSS BOR EACH TOPCOAT 301-392 301-S85 DETOE SWP DETOE OTER DEVOS PRIMES SW P OTER SWF PRIMER OVER 3*7-817 *7.6 *2.7 31.* 2/7 29.8 2/7 53-7 2.7 SELF- ' PRIMED 58.1 2.7 *1.9 2.7 37.0 2.7 65.5 2.7 35.9 2.7 65.6 2.7, OTERALL 52.8 i 1.9 36.7 1.9 33.* 1.9 59.6 1.9 DUP030003399 TABLE m EFFECT OF TOPCOAT SPREADING RATE ON GLOSS OVER 347-81? 301-892 301-885 Devoe SW? a- Mean 500 St?.Ft./Gal. 750 Sa.Ft./aal, Difference 54.1 3.8 41.1 3.8 13.0 5,4 36,0 3.8 39.7 3.8 26,9 3.8 20.0 3.8 9.1 t 5.4 19.7 5.4 60.0 3.8 48,5 .3.8 11.5 5.4 Overall 47.2 1.9 34.1 1.9 13.1 2.7 SELF-FRIMSP AMD INDEPENDENT PROPRIETARY SYSTEMS 301-892 3OI-885 Devoe SUP Devoe over Devoe Primer SUP over SWF Primer 65.5 3-8 ' 44.3 + 3,8 46,0 . 3.8 68.9 3*8 44.2 3-8 68.8 3.8 50.6 -3.8 39.9 3.8 28.2 3.8 62.1 3.8 27,5 3.8 62.5 3.8 14.9 5.4 4.8 5.4 17,8 5.4 6.8 5.4 16.7 5.4 6.3 5.4 Confidence limit of any difference between two "Mean Differences": t 7,6 DUP030003400 TABLE T9. EFFECT OF PRIMS COAT SPREADING RATE OK GLOSS a. cmn 37-8i7 301-892 301-885 Devoe SN P Overall *50 SO .Ft,/Sal. 50.* 1 3.8 33.1 3.8 31.2 i 3.8 55,1 3.8 Mean 750 So.Ft./Gal. Difference 44.8 + 3,,8 5.6 + 5,4 29.7 3.8 3.4 + $.4 28,4 + 3.8 2,8 5.4 52.3 + 3.8 2.8 5.4 *2.4 t 1.9 38.8 t 1.9 3,6 2.7 SELF-PRIMED AND INDEPENDENT PROPRIETARY SYSTEMS 301-892 301-885 Devoe Sw P Devoe over Devoe Primer SWF over SWP Primer 57.6 3 *8. *3.2 3.8 37.8 + 3.8 65,6 + 3.8 36.8 3.8 66.2 t 3,8 58.6 3,8 40.6 + 3.8 33.4 3.8 65.4 + 3.8 34.9 3.8 65.0 + 3.3 -1.6 i 5,4 2,6 i 5,4 4.4 5.4 0,2 + 5.4 1.9 $ 5,4 1.2 t 5.4 Confidence limits of any difference between two ''Mean Differences''; t 7.6 DUP030003401 TAB!. W mm s t a n d a r d d e v ia t io n o f in d iv id u a l q l o s s a s ' M&iHO! OVER 3*7-817 301-892 301-885 Devoe S P For n 56 Mean SloSS 47.6 31.*. 29.8 53.7 : * 3.41# p * 99$ . Mean Staa<8ar<8 Deviation 5.26 2.85 5,26 3.86 Mean Variance 27.67 8.12 .87.67 14.90 - 1.83,p * 95$ f * 2?4l ittw 1.85# p 95$ SELF-PRIMED. AND INDEPENDENT PROPRIETARY SYSTEMS 301-892 58.1 301-885 *1.9 Devce 37.0 SIP 65.5 Devoe over Devoe Primer 35.9 SIP over SWP Primer 65.6 for n 56 F 21.25 _u 1.76# p - 95$ 4.04 3.51 *.6l 3.95 3.86 16.32 12.32 21.25 15.60 14,90 3. *7 12.04 V * 21.25 _ iStifw 1.72, p * m 1.40., p < 95$ DUP030003402