Edit, update from Mitchell:

“The chair featured in this article is very old. It was probably well into it’s use
at the time Henry Hudson first made his way up the river which became his namesake.  It was originally a woven seat. It was never meant to be upholstered.
Once the die was cast, the first upholstering created untold damage
o the old and fragile rails, and there was no
possibility of going back to its previous woven construction.

There are many things about this chair’s construction and materials which deserve defining and exploration.  In this brief article I only alluded to those particulars. That said, all the decisions made relative to materials and engineering were considered relative to the impact of the historic parts and the long term preservation of this historical, structural, decorative object.  Once tacks and staples were introduced to the foundational members the seat structure was evermore compromised, as we discuss. The lignum vitae side-rails were split making it impossible for them to withstand the shearing forces created by a woven seats tensions.

As the piece was to continue to grace a home (not a museum), I settled upon a plan of practical engineering which would allow for weight distribution to be spread over the surface of a cushion while also minimizing the impact of downward forces upon the historic structure.  Ultimately, almost all downward and oblique forces were removed from the fragile side rails and instead transferred to the newly fashioned front
and rear rails, floating plywood platform and goose down cushion.”  ~MRP

Before

After

It started when our client noticed her family chair collapsed in the front.  Prior to the 20th century, this chair was a woven seagrass seat.  Previously someone chose to upholster it.  When we brought it in for treatment, we were not prepared for the “hack job” performed during its last  conversion.  A previous upholsterer used an old plywood sign to bridge
the aprons, and applied one piece of webbing to secure the platform, along with various nails and hardware.

To do this to such a beautiful old piece of history
is a travesty and cannot be reversed.

When we fully and carefully excavated
the chair, we found both front and
back apron were terribly eroded by
beetle infestations.  The cause of
the collapse of the apron at the
right-facing leg to apron join was that
a good deal of the apron was missing.
Rather than repair the problem,
previous poor upholsterers had
continued with their “slap-dash” fixes,
this time using a single piece of
webbing to hold up the platform,
or makeshift seat deck. Also, the pressure
of the right-facing apron not holding
its own weight caused the left-facing
apron mortice to pull down and split the
left-facing leg in multiple places.

Further, the lignum vitae siderails had been split along multiple radial lines
from prior successive indiscriminate applications of decorative nails.
Compounding these splintering breaks and voids fragmented sharp staples protruded from the surface and deep gouges to the surface from the sloppy use of previous upholsterer’s ripping chisels used during the removal of previous upholstery covers.

The first thing we did was to remove a gazillion staples and repair the damage previously created by many tack holes in the side aprons. Nail holes were filled with hide glue and hard picks were tapped into each.
This effectively fills the voids in the lingum vitae and creates a stronger side apron.  Due to
age and tight construction,
we elected not to disassemble and replace the siderails.

A Japanese saw  carefully cuts
the pins to the surface, and
these are gently sanded flat.

Old mortices were carefully bored of remnants of mortice and glues.

The centuries old chair was too fragile
to be taken completely apart,
so an innovative apron was designed
to allow a new apron to slip into
the space.  Having seldom seen this
kind of response to the dilemma of age,
my parameters for the new aprons were:
1) to lock or snap into place as
the legs could not be splayed to
insert a new apron,
2) to conform to the original
hand-shaped legs,
3) to be no bigger than the slim
profile of the original apron,
4) and when all parts were in place,
to be locked into position as
a strong unified structure.

To that end I designed an interlocking tenoned bridge.
I used Eastern hard maple for both its slight surface crushing ability and its ability
to hold a tenon when kerfed.  For the kerfed bridge spline/tenon I chose
a thick sliced tangential grain rosewood with white oak locking pens.

Each new apron was
made of several pieces:

1) Two hand-shaped
Eastern hard maple
parts to make each
apron with Eastern
hard maple dowel
inserted into each end,
2) A long locking tangential grain rosewood bridge,
3) Two smaller locking
center joints at the fulcrum, also of rosewood,
top and bottom,
4) Four hard white oak pins to unify the center joint.

Once assembled using hide glues and a mixture of gap-filling PVA,
the apron was stronger than the original, and also beautiful.
I was sorry to have to cover it up!
The new design prosthetic accepted the upholstery perfectly.

In an ideal world the chair might have been returned to its original woven seat.

I did not want to place webbing around the side aprons as an additional seat support because of their modest connection (girth of tenons) and their previous mishandling by upholsterers.  I settled upon the structural bridge and attached the plywood to the
two new rails.  The original plywood signboard was actually a piece of
early 20th century ply, which was made of solid wood core instead of layered veneers.

The plywood was cut in the center to allow for a cushion drop, and furred out to accept foundational webbing.  This effectively dropped the center of gravity in the seat allowing for greater comfort during sitting once the fresh down cushion was installed.

Our client did not want a new silk showcover and asked us to utilize the existing show cover.  Our second problem was the previous upholsterers had cut the original silk seat deck show cover with NO extra margin beyond the eroded stapled edges — they had literally cut it to barely cover the edge of the desk.  The edges were tattered from the staples.  I used a second piece of silk to reinforce and allow for a new secure edge, and also cleaned up the tattered edges by overlocking the edges so they were no longer unraveling.

Hair and cotton batting to soften the edges, and the new deck
was placed onto the repaired seat with just enough room!

The previous cushion was replaced by a new handmade down cushion with baffles to keep the feathers from migrating.  I also reinforced the edges of the original show cover as the prior upholsterers had not overcast the edges, so the cushion silk would not unravel.
Note:  The shape of the cushion was not our design:
we simply created the new stuffing.
We might have suggested a very different type of cushion.  However, with the new stuffing, as the cushion is sat upon the down will compress over time, allowing the sitter to
not only drop into the seat properly, but will also insure that the sitter’s weight will now
be evenly distributed over the entire chair’s structural surface, mitigating the
potential destructive downward force upon the four hundred year old frame.

With a little bit of extra care by the owner and the careful choosing
of future upholsterers, this chair should grace their home for another century.

Before

After

After with cushion not ours.

Before and after, with
and without cushion, above.

Written by Mitchell Powell  ©MPF Conservation.
May be printed for your own use ONLY, not for use on blogs without permission.