THE GLUING OP WOOD 
43 
tice. The test data obtained were analyzed, and the combinations of 
conditions which had given the most satisfactory results for each 
glue on all species were selected. With the exception of the Osage- 
orange species, the combinations selected for the casein and for the 
vegetable glues were applied alike to all species. The data for animal 
glue were selected to give a fair comparison of the remaining 39 spe- 
cies. The average test results are shown in Figures 12, 13, and 14. 
VEGETABLE GLUE 
Sp£C/ES* 
Wood ,=o1iw-s -■-?- Ce-f* 
Srear o?r~enqi-k —lbs pe** 5a In? 
1000 ' iOOO 3000 
Snrure Sitka (Pirm .<i/fr/n°n.v,.?)* A 
Cedar, western red (Thuja pficata)L % 
Fir whtfv (Ann** rnnmlnr)* O 
Hemlock western (Txuaa het^mnhijiln)' 4 ' ® 
Ba^sr/ond CTttta 3p)* 
Ain't"* aw/ fA/nu<: ruhr/iY 
Rrdwnnd f.^nunm *rmne>rv l rs*n<:} 2 ® 
Butternut CJunlan.^ rm^r^n) 2 
Chestnut fCa.'sinr^a drntatv) 2 
I 
Prr,o nnrthfrn v*>ht'+e> (Pinu* T/r/)A//?]' 4 d 
Cedar, eastern red (Jumperus wr^mtano)' 4 . ® 
2SA- 
Poualas fff (Pseudotsuqa taxtfolta)_ ® 
Gum. red (sopwood) (L/awdambar sfi/rac/f>'ua) 
Pino .*md-hf>rn n**/fn», f Pinti* c/n X 4 © 
Pecan (Hiccria n^ran) 
F/m Am^r/rnn t ' Ulmus nmtzr-ir-nnaV 4 
i 
-f— 
^■■^— „ 
Finn rcrk (Wrnus rarrmnsa)- 
Maano/za (Mnnnnfia .?r>) * 
Walnut h/rtrk (Jurtfanx mam) 2 
? 
s 
Mapfa xn-ff (mmmrmnf) (Arer JFp}' 4 
Oak red Ccnmmerrm!) (Qurrrux «?«!•* 
Cum tun* fn (rnmmrmnC) fNtit.vsi .*n)'* 
*- 
Cum h/ark (rnmm^r/n/) (Nij.^xa tp)* 
Gum, red Creartr/ood ) (Uquidami&r stura-c/f/ua}£_ 
Cedar A.'aska (Chamaecupans noofkatens /s)>* . & 
froprh (Fhst/j* /irnndifnlitt) 
Cak wh,fr (rr>mme>rrmt) (Qu^rrut *n) 2 
Perstmmnn (Dmxnyrn t viramtnn/i ) ' 
Afh trvh/tf (rnmmrrrtswt) Crrstrinu* <?r>) 4 
Bmrh yrffov* (fatufa ///Aw,) 4 
I'""" 1 " ! — !— 
Otae-fP-nr-anae CTnxij/nr nTntfarj/sn) 2 
■bfc 
-A- 
I -Common and sctenfff.c names are 
3-Mostft/ heart nood 
4~ Hear TYYQod and sopirocd mfjred 
S- Soptvood 
-'~ S'J>-^_t-j ~s~-- 
>n of the joint arVB of the 
fhe sheaf strength of i 
other; belong So the 
r.anated "( 
published m US Pcpt Aar Bull 
Figure 12. 
-Results of tests on joints of various woods glued with vegetable glue. 
Values shown are averages of 45 to ISO specimens 
The test results are expressed both in percentage of the joint area in 
which failure occurred in the wood and in the breaking strength in 
pounds per square inch of joint area. 27 Failure in joints usually 
occurred partly in the wood and partly in the glue line. " Percentage 
of wood failure " refers to the proportion of the joint area of the 
specimens where wood fibers were torn away in testing. In Figures 
12, 13, and 14 the species are arranged in order of wood failure 
developed in the tests. 28 Wood failure combined with the shear 
strength of the joint is used as the criterion for judging the effective- 
nessof the gluing. Where the wood failure is at or near 100 per cent 
the joints obviously had been glued satisfactorily, irrespective of the 
27 On account of difference in testing apparatus and character of test specimen the 
strength values given in this bulletin for joints are not comparable with the strenglh data 
published elsewhere on solid wood. 
28 Where two or more species showed the same average percentage of wood failure they 
are arranged in descending order of the strength of the joints. 
