Nothing is so necessary to the saving of time and energy as an orderly
shop. Our boys had bought a quantity of white pine to begin operations
and it was lying in a pile on the floor where it was always in the way.
To cut a piece of stock from one of these 12-foot boards it was
necessary to use two kitchen chairs for trestles, so it was decided to
construct two saw horses, and as soon as they were finished, to build a
lumber rack against the wall where their little supply could be stored
out of the way.
"We will carry out our regular practice by first making a drawing,"
said Ralph. "We know from experience that it saves time."
Fig. 92 shows the proportions of the trestle at _a_, and the mechanical
drawing with all dimensions at _b_.
The body of the trestle was built up of four pieces, two long and two
short ones. The open space in the centre, Ralph explained, would make
a convenient tool rack where hammers, chisels, etc., could be placed
while they were working, especially at outdoor work, instead of being
dropped on the ground. The body then called for two pieces 3 feet long
by 4 inches wide, and two pieces 10 inches long by 4 wide.
These were sawed from a rough plank with the rip saw by using the
chairs as trestles. A pencil line was laid out 3-1/4 inches from one
edge, and the saw cut made directly on the line, 8 feet long.
The cross cut saw was used to cut the strip off and this strip was then
sawed with the same saw into four pieces of equal length for the legs.
Another strip 4-1/4 inches wide, 7 feet 8 inches long, was ripped out
and taken off with the cross cut saw, for the body, and divided into
two pieces 3 feet 10 inches long, for convenience in planing.
Harry now had his first real experience in planing. All the pieces were
of 1-inch rough lumber, with sawed edges, and had to be planed down to
7/8 inch in thickness.
To plane six pieces of stock straight and true, with squared edges and
of definite size, was no easy task.
"How do you like manual labour?" asked Ralph, mischievously.
"I like it all right," replied the perspiring boy, "but we won't need
any gymnasium work for exercise while we are doing this."
[Illustration: Fig. 92. The trestle or saw horse. By permission of
_Carpentry and Building_]
"Wouldn't you like to make a bench in hard wood right away?" asked
Ralph.
"No, I guess you were right after all."
Ralph showed him the proper way to stand, and how to hold the
jack-plane so as to get the best results. He promised to show him how
to sharpen and adjust the plane as soon as the lumber was stored away
on the lumber rack.
Harry's business was to dress down one of the flat faces of each piece
till it was smooth, straight and true both with the grain and across
it. He tested it by his eye and the edge of his plane and when he
thought it was about right, passed it over to Ralph for criticism.
Ralph was a very exacting instructor, but made allowance for the boy's
inexperience. He was making the second trestle at the same time and it
was exasperating to Harry to see the ease with which he turned out his
work.
"Never mind," said Ralph, "you can do as good carving now as I, and in
a few weeks you will be able to do just as good joinery or carpentry.
The first day is always the hardest. You are all impatience and want to
get through right away. After a while you will learn by experience that
you can only do one thing at a time, and will not rush so."
[Illustration: Photograph by Helen W. Cooke. Using the Jack Plane]
Finally, one face on each of the six pieces was pronounced finished,
and the next step was to "joint" or "dress down" one edge straight,
smooth and square with the working face--the first planed surface. This
seemed easier after the experience of making the bench hook, and Harry
knew how to test for squareness with the try square.
Working on the two long pieces for the body, both edges of each were
squared up, a 10-inch piece was marked off on one end of each with
pencil and try square, and sawed off with cross cut saw.
It was decided to leave the inner faces rough, as they would be inside
the trestle, and out of sight. These four pieces forming the body were
now nailed together with 2-1/2-inch wire nails, as shown in _a_.
The four pieces for the legs were dressed on all four sides, and it
only remained to cut the angle at top and bottom.
This brought into use a new tool, the bevel. The angle _x_ was found
by laying the bevel on the mechanical drawing, and fixing it at the
angle by tightening the set screw provided for the purpose. The line
was carried across the face by means of the try square, and the bevel
used on the farther edge. When this laying out was finished, the piece
looked like _c_, the triangular piece _y_ being removed by sawing
directly on the pencil lines.
After the four legs were laid out in this manner and cut, they were
nailed to the body with 3-inch wire nails.
The saw horse was now complete with the exception of the two braces,
and the final truing up.
The braces were made by holding a piece of stock 4 inches × 7/8 inch in
position and marking the slope with a pencil, sawing to pencil lines
and nailing in position _d_.
The final process of truing up was an interesting one to Harry, and he
used it many times afterward in finishing pieces of furniture, such as
tables, tabourettes, etc.
The horse was placed on the bench, and a pair of dividers set as shown
at _e_.
A line was scribed on each leg wherever the compasses point touched
it, holding the latter upright and going around all four sides of each
leg. By sawing to the lines made in this way, the trestle was found
to stand on the floor perfectly true. This is a method much used in
truing up articles that rest on three or more legs, and it overcomes
any inaccuracies that may have arisen in the process of assembling; but
it is very important that the surface on which this truing up is done
shall itself be perfectly true. The bench used in this case was new
and had not yet warped at all, but an old bench might not have been
suitable. This can be ascertained by testing the surface in several
directions with a long straight edge.
The facts of warping and shrinkage in wood must always be taken into
consideration.
The saw horse is an important part of every shop equipment, and the
boys now relegated the clumsy chairs to the kitchen, where they
belonged, and were prepared to saw out stock from their longest boards.