Thursday, January 29, 2015

Wood Sandwiches and Warped Doors

My Son was helping me out at the studio one day and he got a bit distracted. I know he said he was hungry but I wasn't paying attention.

Hence the salami and Swiss on rye sandwich.
Or rather amaranth and satinwood on pine.

I thought of this as I was thinking of this post.

The layering of wood into a "sandwich" adds some interesting and useful properties that can be utilized for fabrication and restoration.

Sandwiched Wood
Some History

Plywood has been with us arguably for centuries. I say arguably because  the references and discussion of purpose and reason vary.  The arguments go from stability of the groundwork to the conservation of materials  - and pun intended it falls somewhere in-between.
It has never been the material of choice for me - but it does have it's purposes. The oft quoted line is "If Chippendale had plywood he would have used it." He may have, but my gut feeling is that we would probably have fewer remaining examples of his craftsmanship.

By veneering your most precious materials on to a dimensionally stable groundwork you are conserving the valuable figured wood. Slicing the presentation timber into thin veneers allows you to cover a considerably larger amount of surface - as opposed to using the original board in solid.

Imagine a day on the end of this saw
This technique of cutting valuable timber into veneers was implemented regularly  in the mid 17th century for just this reason. The problem is that the process of cutting the veneers was done entirely by hand. A time consuming and very laborious process. Consequently, the fabrication of a plywood groundwork would have been much too labor intensive, therefore the resawn presentation veneers were typically laid upon a secondary wood of pine and sometimes mahogany.

The following earliest reference from an examination of an Egyptian coffin was done (in my opinion) entirely for stability. Wood expands and contracts with the addition and removal of moisture across its thickness. By layering thin sections of wood crosswise into an panel, the movement is minimized and counteracted by the opposing layers.

From Pharaonic Egypt
The oldest piece of plywood was found in a third dynasty coffin, made of six layers of wood each 4 mm thick and held together by wooden pegs. [11] Like modern plywood the grain of its layers was arranged crosswise to give it added strength. [12] From 1750 BCE onwards this plywood technique became widespread. The thickness of the layers was reduced to less than three millimeters and they were stuck together with a glue made from bone, sinew and cartilage applied hot. [13]

The Rush of the Machine Age

In 1797 Samuel Bentham applied for patents covering several machines to produce veneers. In his patent applications, he described the concept of laminating several layers of veneer with glue to form a thicker piece – the first description of what we now call plywood. Samuel Bentham was a British naval engineer with many shipbuilding inventions to his credit.

About fifty years later Immanuel Nobel, father of Alfred Nobel, realized that several thinner layers of wood bonded together would be stronger than one single thick layer of wood.

 Plywood was introduced into the United States in 1865 and industrial production started shortly after. In 1928, the first standard-sized 4 ft by 8 ft plywood sheets were introduced in the United States for use as a general building material.  From Wikipedia

With the advent of this invention it was now possible to manufacture engineered panels with increased strength and dimensional stability. A stable groundwork for veneer that was resistant to warp and shrinkage splits.

Which leads me to the subject at hand... warped cabinet doors.


Warped doors on cabinets are a fairly common occurrence. Often they can be coaxed into an acceptable position by adjusting the hinges. This doesn't remove the warp but only balances the panel and frame in the opening.

In the case of our current patient a more invasive procedure was required. (Using what we've delved into previously plywood seems an option.) The stiles were warped and twisted enough to pull the door almost 2" out of plane when closed. Even the original heavy duty compression latch wasn't enough to keep it closed.

Taking apart the wayward door was in this instance almost half the battle. Being a newer reproduction piece the joints were glued with synthetic modern adhesive which proved to be rather resistant to dis-assembly.

Once the door was apart the stiles were bandsawed through their entire length to remove the tension in the wood caused by the warp. Before proceeding to the next step the saw kerf was cleaned up with a hand plane.

A new piece of wood, the thickness of the material removed by resawing was then glued between the 2 pieces of the stile and clamped on a flat surface to eliminate the distortion. A wood "sandwich", or in essence plywood. By gluing up the pieces with a core of quarter sawn kiln dried birch, the tension was distributed between the three pieces and the glue joint.

After removing the flattened piece from the clamps, the excess material was trimmed to blend with the original. The joinery was cleaned and refitted to correct for any remaining distortion and the door was re-assembled.

Stile in clamps
The "Sandwich" prior to trimming

The Completed Project

Closeup of spline

Additional Photos Here

Sunday, November 10, 2013

Locks and Keys

While not usually essential to the functioning of a piece of furniture. A working set of locks and keys does add to the aesthetic quality of an antique.

Subject to the same deterioration that effects the wooden structure,  the metal oxidizes, rusts away or simply wears down from use.

In the case of this pair of locks the bit on the  key supplied with the credenza was too short to through the bolt and one of the locks was missing the bolt entirely.

The locks themselves are from a 20th century reproduction but the mechanics and parts are essentially the same as those in a period mortise lock.

First stop - the metal scrap bin.

I collect bits of useable metal scrap left over from projects or salvaged as I find it.

To make the replacement bolt for the lock I needed some 1/8" thick mild steel.

Having found none in my "collection" I opted to make the missing parts in brass.

Making the Bolt

The brass stock was heated to remove its temper making it soft(er) and easier to shape. The remaining original bolt was removed and used as a template which I scribed around.

The shape was then cut out with a jewelers saw and finished up with needle files. 

Since the section of the bolt which extends out of the throat to engage the keeper is thicker than the internal plate, I cleaned the surfaces and brazed on enough material to make up the difference.

The finished locks with the parts in place

The Key
The bit on the supplied key was too short to engage the bolt and was therefore used to pull open the doors without actually locking or unlocking the piece.

As you can see in this photo the bit was short by about 1/8".

In order to correct the problem a small piece of brass was brazed onto the end of the bit and then filed to mate properly with the bolt.

Additional Information

I found this article explains a lot of the terminology and history
The Keys to Antique Furniture Locks by Fred Taylor

Additional Photos on Flickr

Saturday, November 9, 2013

Bits and Pieces

Completed Repair
This piece came into the studio with several condition problems.

The Chinese silk embroidery panel was distorted because of breaks in the support frame for the embroidery, and the stand itself was missing a carved bracket and several pieces of mother of pearl inlay.

My "impression" is that the silk in the frame is not the original occupant, but a period section of fabric trimmed to fit the original missing artwork.

The embroidery had been lined much like a canvas for a painting and the brown silk border was sewn around the spruce stretcher and then strung taut in a rather "shoe-lace" fashion across the back.

I started out by reinforcing the damaged stretcher support. Pulling back the lining and isolating the material with glassine, I glued the shattered spruce elements and reinforced the breaks with strips of new spruce.

A side note: the clamps are actually older style Intravenous tube clamps that I purchased at American Science and Surplus. The small hemostat clamps came from there as well. A great source for odd and unusual bits and pieces.

The frame itself was missing one of the carved support brackets so I traced one of the originals and set about carving the replacement.

The original is on the right

The mother of pearl inlay was an easier task. Again tracing the replacement from an original (in this case a flower) and then engraving the petal detail before resetting it in the groundwork.

Detail of the embroidery
As usual there are more photos on Flickr

Lid Repair

Stand Repair


Turned Profile


The Original

The Replacement

Additional Photos on Flickr

Monday, May 14, 2012

The Trunk

I know - I should always take before photos. But sometimes, I'm all in a rush, or I think the object mundane.

Wrong again.

It was in a fairly decrepit condition and the guidelines of the treatment were narrow.
  • Better - but not perfect
  • Attractive - but not expensive
  • Functional "as is" - without jumping through too many hoops

    So I cleaned all of the exterior surfaces. Removed the miniscule remnants of tooled leather that originally covered the open fields of pine you see here. Cleaned the old japanning from the strapping, and replaced the missing leather handles.

    Here you can see the original tooling pattern of the hide. From the indentations it was tooled in place after application.

    I love the details on the hardware

    A coat of amber shellac on the wood surfaces, yellow tinted shellac on the hardware and bone black pigment on the strapping. The interior I lined with fabric on removable mat board, so that it could be used for storage.

    I was gratifyingly surprised at how well it pulled together without going to extremes.

    Remnants of leather

    The Maker

    A little digging on the "internets" yielded a small amount of information on the maker.

    Who's who in Chicago 1905
    The book of Chicagoan s
    John William Leonard, author 

    Wilt, Charles T., manufacturer; born St Louis, Mo., Nov. 22, 1859;.
    Son of Charles T (Sr ) and Emerette A. (Babcock) Wilt; came to Chicago in childhood

    Education. Ogden, Newberry and Lincoln schools, graduating from latter

    Married Chicago, July 31, 1888 to Charlotte D Fairbairn;
    Children: Charles T., Jr., Collin D. Robert Lloyd Wheaton, Elmer Ellsworth.

    In 1878 entered business (founded by his father, 1862)of Charles T. Wilt, manufacturer in trunks traveling bags, etc.; is now head of firm, which is still conducted as Charles T. Wilt.

    Republican. Captain. 1st 111. Voluntary Infantry, served through Santiago campaign of Spanish-American War. Member of the Veteran Corps, 1st Regiment