Manual of Purpose-Made Woodworking Joinery

6 Softwoods and hardwoods

DEFECTS DURING GROWTH

Deadwood

This term refers to wood from a dead standing tree

that lacks strength and its usual weight, symptomatic

of the tree being felled after reaching maturity.

Druxiness or dote

These terms refer to early decay which appears as

white freckled spots or white streaks – due to fungi

germs entering the tree through broken branches or

other damage.

Twisted fibres

Figures 1.3(a)(b): This is recognized when the rea-

sonably parallel lengthwise grain or fibres of a piece

of converted timber are seen to slope off within the

width or thickness of the timber. This is caused by

straight cuts through a distorted tree trunk. Certain

instances of this, as illustrated at (a), can cause short

grain, which may seriously weaken that part of the

timber and make it unsuitable structurally. Also, as

illustrated at (b), if a length of sawn timber contains

a few grain- twists (especially close together), causing

it to take on a serpentine shape, it is difficult to plane

the affected surfaces from either direction without

being against the grain.

Cup shakes or ring shakes

Figure 1.3(c): As illustrated, these are segmental-

shaped splits – some wide, others narrow; some short,

others long – between the annual rings, reckoned to

be caused by the sap freezing in the early spring. After

log conversion, these concealed shakes are transferred

to the surfaces or edges of the sawn stuff and can

present themselves as pointed pieces of spear- shaped

fibres that spring up dangerously during machine- or

hand- planing operations. (As a C&J apprentice, whilst

manoeuvring a room door that I was hanging and

had just shot in (planed its edges), I had the painful

experience of being speared in the fleshy part of the

hand between the forefinger and the thumb by a long,

wedge- shaped, tapered splinter that sprung up unseen

from an arris edge.)

Heart shakes and star shakes

Figures 1.3(d)(e): As illustrated, these can be single

or multiple splits that radiate from the pith (heart

Figure 1.2 (h) Four examples of distortion through

unequal shrinkage.

(h)

Figure 1.3 (a) Weak short grain (on R/H side) created

by twisted fibres; and (b) Serpentine- shaped fibre twists

that can create planing problems.

(a)

(b)

Figure 1.3 (c) Exaggerated
appearance of cup or ring
shakes; (d) Heart shakes; (e)
Star, radial, or circumferential
(c) (d) (e) shakes.