A PORTABLE RESTORATION WORKBENCH
Donald C. Williams

(Part of a much longer piece, originally comissioned by AWW, who decided
not to publish it nor pay me as promised once I gave it to them. I have since
learned better.)

One major problem to working "on-site" is outfitting a temporary work station,
especially finding a tool that is both portable and a good workbench.
The sawhorse and plywood routine had to go. But what could take its place
as a "perfect" portable workbench?

Looking at the market to see if any of the available "portable" workbenches
were suitable, there were only two real options; a small, folding version of
the European-style butcher-block-top bench, or a Workmate. Neither was
satisfactory, either being too unsteady or too heavy. The search for a
suitable manufactured bench wasn't exhaustive, but nevertheless, I decided
to build my own portable workbench to the following specifications:

1) the top had to be perfectly flat and at least 2' x 4'

2) it had to have a vise sturdy enough to take a modest beating

3) the bench had to be very light, compact, and easy to set up and take
down (no loose parts!)

4) it couldn't cost a fortune or take a long time to build

The bench wouldn't have to withstand immense weight or stress, since the
pounding necessary during general joinery is rarely required in a restoration
project. Any heavy work dictated by a particular treatment would still have
to be done at home.

This bench is not an example of exquisite hand-worked joinery, but did require
precise machine woodworking techniques. It is completely functional and
satisfies the requirements listed above. The top, which could be made any
size, contains a pair of 24" twin-screw face vises which open about 12".
The bench folds up into a compact unit weighing about 50 lbs. The braces,
which fold with the base, provide plenty of stability to the bench allowing
even more aggressive cutting and pounding than expected. And, it only took
about six well-planned hours and $75.00 - $100.00 worth of materials to
build the basic unit.

The Top and Vises

Because of the rigidity and weight requirements, the obvious choice for the top
was a torsion box. Using 3/4" plywood for the frame and 3/8" plywood for both
the faces and ribs, and making the box approximately 3" thick, placing the ribs
in a 6" x 6" grid, achieved a satisfactory result. Large vise capacity was desired,
but there was no point in defeating the original purpose by building a lightweight
bench and then installing heavy vises on it. These vises open about 12" and
employ aluminum threadstock for the screws (1" x 8 TPI), and 2" x 3" x 24"
softwood jaws. The screws pass through holes in the movable jaw, and are
affixed to it with split retaining rings on the outside of the jaw, and terminate
in simple handles.

Incorporating the vise into the bench top involved drilling oversized holes in the
grid but not the fixed jaw, so the box could not be assembled all at once. The
grid pieces were glued to one face of the box using 315g hot hide glue. Then,
holes were drilled through the end grid frame (fixed jaw) and tapped to receive
the threadstock screws. To allow for any wobble in the screws, larger holes
were drilled through the interior grid members. The threadstock screws pass
through these openings as the vise closes. After making sure the vise was fully
operational, the second face was glued on the grid and the top box was complete.

The Base

Equally problematic was the selection of a base structure. A trestle base was
considered, but this idea had some significant drawbacks. While easy to build
and assemble, the knock-down trestle has multiple parts, and one of the primary
intentions was to not build anything requiring loose pieces. Commercial tubular-
steel folding-table legs worked well along the short axis of the bench but weren't
stiff enough along the long axis because of short diagonal braces. Simple leg end
units with long folding diagonal (longitudinal) braces, dealt with the problem.

The base was fabricated from clear 2x construction lumber and birch plywood,
and the folding braces from 1/4" x 1" aluminum bar stock with 1" x 1" aluminum
angle stock for the mounting brackets, joined with 3/8" bolts and nuts. Wood
battens were glued to the underside of the bench top, and the end/leg unit hinges
and the folding brace brackets were screwed to the battens. The leg units were
not installed symmetrical relative to the long axis, but rather were off-set by half
the leg width so they could fold up next to each other rather than on top of each
other. This way, the table could become a compact unit which needed absolutely
no assembly or disassembly; it could just be folded up. Using an attached
carrying strap, the bench can be carried easily for long periods of time and
maneuvered through pretty tight quarters.

Unfortunately, the lightness which was such an asset for the "perfect portable
bench" was a big liability once the bench was set up. The bench was so light
that any hard work was impossible without moving it or even knocking it over.
Some way of weighting the bench while in use was required.

The "no loose parts" vision was about to bite the dust. Fortunately, the solution
was as simple as building two thin (approx. 1-1/8") very lightweight torsion boxes
to serve as shelves resting on the crossbar of the end/leg units on either side of
the folding bracket, and which could be firmly attached to the underside of the
bench top with Velcro when not in use. By placing tools and supplies on the
shelves, the bench had enough mass for use. It still wasn't heavy enough for
general cabinetmaking, but it was more than adequate for on-site restoration.