THE GLUING OF WOOD 
47 
Table 4. — Results of tests on gluing properties of hearticood and sapwood 1 
[H= heart wood; S= sapwood] 
Species 
Ash, white _H 
Do S 
Birch, yellow H 
Do S 
Cedar, eastern red H 
Do „_S 
Gum, red H 
Do ____S 
Magnolia H 
Do S 
Maple, sugar H 
Do 8 
Pine, northern white.. H 
Do S 
Pine, western yellow H 
Do S 
Walnut, black H 
Do S 
Animal glue 
Shear 
strength 
Lbs. per 
sq. in. 
2,354 
2,259 
2,711 
3,174 
1,345 
1,919 
1,975 
2,080 
2,352 
2,573 
3,998 
3,905 
1,258 
1,476 
1,605 
1,531 
2,104 
2,738 
Wood Specific 
fail- gravity 3 
ure of wood 
Per 
cent 
89 
94 
73 
64 
81 
100 
96 
92 
66 
70 
100 
100 
68 
100 
72 
85 
0.54 
.53 
.66 
.64 
.47 
.46 
.53 
.51 
.47 
.53 
.71 
,39 
.56 
.53 
Casein glue 
Shear 
strength 
Lbs. per 
sq. in. 
2,114 
2,272 
2,321 
2,957 
1,686 
1,518 
1,731 
1,849 
2,279 
2,501 
3,854 
3,028 
1,202 
1,351 
1,590 
1,616 
2,124 
2,558 
Wood 
fail- 
ure 
Per 
cent 
59 
53 
32 
49 
85 
99 
58 
84 
78 
100 
39 
26 
85 
94 
80 
94 
54 
Specific 
gravity 3 
of wood 
0.55 
.53 
.65 
.66 
.48 
.39 
.54 
.52 
.53 
.48 
.71 
.67 
.37 
.37 
.40 
.37 
.58 
.57 
Vegetable glue 
Shear 
strength 
Lbs. per 
sq. in. 
2,320 
2,332 
2,711 
2,879 
1,660 
2,052 
1,975 
2,103 
2,587 
3,066 
3,874 
3,287 
1,254 
1,449 
1,798 
1,538 
2,303 
2,672 
Wood 
fail- 
ure 
Per 
cent 
58 
70 
36 
48 
92 
95 
Specific 
gravity 3 
of wood 
0.5S 
.50 
1 Each test value shown represents 20 specimens or more. 
2 Used under good gluing conditions (see Tables 6 and 7) . 
3 Specific gravity is based on oven-dry weight and volume at about 
per cent moisture content. 
ANIMAL GLUE \ 
Species 1 
Wcod Fa. f u re - Per Cer. t 6 
S^ear- orr-e^arn — Lbs per sq in 7 
1000 7 soeo 3000 
f~7r- whrt* (Jhit>x r-nnrn/nr+Y* ® 
i ' frjj a |L 
-F 
4- 
f)a*dnn« watt**** r>*rt (Th.jirt n/.rnt^ 9 
Spruce. S> <tko (PtCPQ **fn/tMJ*t**+ 8 
4- 
— \— 
Hfimlnrk ivPc/p^fA^rt h*>f/*rs>jnhyff/*)' 4 ® 
ii~~ 
—— - 
! i 
1 1 
> 1 
! i 
i 
- . iyn,| , 1 
Mahnqnnij (fntit>tt>mt* tp) £ 
■ 
P^mn (h , /mr'in r\/=>rrtrt 1 
Cedar, /)/asAa (Chamaecupons roof*atensi$)— ® 
! • 
Gum, red (sapwood) (Lsquidambar sfsjrociflua)f- 
' 
I ! 
» 
||; 
raaa 
fia.<?.*iwnnd (Til in SP) 
-+— 
*Maqnoha (Maqnoha spj* 
■ i— i— 
Cedar, eastern red (Jumper us yirq/riara)^. ® 
— - 
| 
fi&orh (r~fiat£9 rjrnnr/ifn/in)' 4 
0/rch qeltor/ (Betu/a futea)* . . 
j ; ; 
Map/e. Sugar (Acer saccharum)— . . 
■ 
-H- 
Osacfe -oranqe (Toxqlon pomiferum) 
— ' — 
'"I'M 1 i i 1 i i 
i 
»xe<* 
/-Common and SCi&ritifi 
2-/ieartr*ood 
5 -Mostly hearfwood 
4-ffeorfwood and sapwood 
5' Sapwood 
6- Wood failure percent indicates 
7 The shear strength of joints /snot 
id differences m the test method. 
Vindicates wood's of the softwood 
e rhe sfandord names g. 
not identified 
estimated proporti 
t/h US.Pcpt. A?r. Misc Ore- ?2 except those designated°(CommercialT 
of the joint area of the specimen where wood fibers were torn away 
of so/id wood, published m C/S Pept Agr 3ul Ssa and e'sewhere,d. 
parous c/ass 
h the shear streng-, 
>nd specimens- used 
noryporous class ; ethers belong 1o the hardwjjd 
Figure 16. 
-Results of tests on joints of various woods glued with animal glue 
under starved joint conditions 
