Manual of Purpose-Made Woodworking Joinery

The non- gluing of boxframes 61

mentioned that when fixing cords, only large- headed

galvanized clout nails of not- more- than 18mm length

(or traditional heavy- duty galvanized staples), should

be used. Double, conjoined knots should also be used

for attaching sash cord to weights and a steel washer

and split pin is one method of attaching chain to

weights – if the weights have a counterbored side-

hole.

THE NON- GLUING OF

BOXFRAMES

First, it must be mentioned that traditional box-

frames were always dry- assembled and nailed – only

the sash joints were glued (with non- waterproof

animal- adhesives, such as Scotch glue), or painted

with a lead- pigmented primer and dowelled after

wedging, to keep the joints together. Nowadays,

totally waterproof, improved PVA- type hybrid resin

adhesives, such as EverBuild’s D4 Premium Wood

Adhesive – conforming to EN 204 and BS 4071 –

can be used for interior and exterior joinery. My ref-

erences here, therefore, are for replacement boxframes

to be glued.

GROOVES FOR CORDS OR

CHAINS

Figures 4.9(a)(b): The stopped grooves that are
required in the sides of the sashes for housing the
sash cord (or chain) are usually 13mm wide × 10mm
deep. They can be formed after the sashes have been
glued and cleaned up (planed and sanded) and they
stop at least halfway down the sash. Figure 4.9(a)
shows the most common stopped groove, which can
be formed with an 050 plough or 045 combination
plane (after making a short relief groove by chisel-
chopping with a firmer chisel, etc), or more easily
with a portable powered router, or other machinery.
And 4.9(b) shows a method that can be used for
chains or cords – whereby a 22mm Ø hole is drilled
to a depth of 22mm and positioned at least 75mm
further down from the stopped groove; then (at the
end of the stopped groove) a 9mm Ø tunnel is drilled
sloping slightly inwards to enter the mid side- area
of the larger hole below. The idea being that after
threading the cord through the tunnel, a double
knot (two knots like conjoined twins) is tied within
25mm of the end, pulled tight, then hammered
into the hole; and if used for chains, a steel washer
and opened split- pin are attached to the end of the
chain and pulled into the large, counterbored hole.
Although joiners only usually make and fit the sashes
and carpenters hang them after glazing, it must be

7

Figure 4.8 A vertical section through a typical tradi-
tional sill, showing a ventilation/weather bead (7) with
a friction- relieving shape against the sash- face. Note that
if the ends of this bead are tongued and grooved into
the lining on each side, it must be pre- mitred to meet the
vertical staff beads and fitted and fixed with the inner
linings.

Figure 4.9 (a) Sash cord fixed to a common stopped

groove with three large- headed, 18mm long clout nails

positioned at about 50mm apart at the lower end of the

cord; and (b) A stopped groove with a short tunnel of

9mm diameter at its end, sloping slightly inwards to enter

the side of the 22mm counterbored hole below.

(a) (b)