Friday, April 12, 2013

Lecount Clock Project

Not your typical "Cut List"

I'm not very good at keeping records of my work.  I guess that is because I enjoy so much the actual process of working by hand at the bench that I just don't think of taking time to photograph or record what I am doing.  I go to sleep thinking about what the next steps are.  I get up and walk to work visualizing my job.  I start the glue pot, walk over to the bench and start working.  At the end of the day, I go home and start over.  I guess I still have an abundance of enthusiasm for my job, even after doing it for over 40 years.

In any rate, I have decided to try to post some photos of this project, as I think it is interesting on several levels.  It is the fifth tall case clock I have made in the past decade.  As usual, I start building these clocks for my own house, and as usual, they get sold before I can get them home.

To start with, I gather some wood and make some notes about overall dimensions, using metric measurements.  I never took wood shop in school and never learned about a "cut list" or "plans."  I am an analog thinker, so I just imagine the job, select some nice wood from the wood pile, and start cutting.  With the clock I just build the case directly from the back board.  Starting with the lower box, which I posted earlier showing the full blind dovetails, then clamping together the middle section after that.

Everything so far is dry fit and held with clamps.  The reason is that I now need to take it all apart and glue on the marquetry surface, using the press.  Once the marquetry is in place, I can then glue together the case and cut the moldings.  Once the lower case is assembled and the works are set on the cheeks, I can take some final measurements for the bonnet, and start building that.

Lecount born again on the bench

Last week I got the oak case clamped up fine.  This week I spent drawing the marquetry panel for the lower front box, and building the packet, cutting it out and putting it together.

I like to capture the style and use the process that was used during the last decades of the 17th century for these clocks.  Typically, the design has large flowers placed all over the panel, with leaves and branches connecting them.  No attention was paid as to whether the same branch had different flowers or not, and it was not supposed to be a realistic picture of nature, as was done much later in the 18th century.

The Painting in Wood process requires that all the different species of wood are placed in their proper position in the packet, in different layers, and cut at the same time as the background.  The blade is at 90 degrees and leaves a gap.  Inside the leaves and flowers the gap is decorative and filled with a mastic.  On the outside of the elements, the gap is generally not visible, as the background is usually ebony during this period.

Working with scraps to determine the color placement

This process is somewhat wasteful of material, so the pieces of veneers are cut only slightly larger than the design element requires.  The area between the veneers is filled with a cheap species of veneer so the layer remains flat with no voids.  Usually a design with 10-20 different species can be assembled with a packet using less than 8 layers.

Typical layers with different species in place

Note I am using sawn veneers, as usual.  These veneers are 1.5mm thick, and including the 3mm back board and 1.5mm front board, the total thickness of this packet is 13.5mm.  The packet includes (from back to front): 3mm back board, grease paper, full layers of ebony (background), green dyed veneer (leaves), mahogany (branches), three layers of multi species veneers, and 1.5mm front board with the design.  All these layers are taped together to make a solid packet.  No nails are used; only veneer tape.

Using the chevalet, I cut out all the elements and keep only the wood species I need for the design.  The ebony background is then placed on a board covered with blue masking tape, face side up.  Note: this is a "modern" idea that I got from Paul Schurch, a good friend and very talented artisan in this field.

Burning the elements in hot sand, with coffee

The individual elements are carefully burned in hot sand to create a shadow according to a drawing I made.  This is the boring part, but without it the picture looks flat and lifeless.  Sawn veneers take more heat and much longer in the sand to properly shadow.  I use a very fine sand I purchased in France and an industrial hot plate made in Germany.  You need at least 1500 watts or more, and the sand needs at least an hour to reach proper heat.

Ebony background ready to place on blue tape

By using the blue tape to temporarily hold the background in place, I can assemble the picture face up, so it is much easier to follow the design.  This also allows me to exchange any pieces which I think are not the best choice of material before everything is glued down.  As most of the flowers and other elements have at least two different colors, I can change the composition of woods as I want.

Front of Panel held on blue tape

Then I make an assembly board using Kraft paper.  I put hot glue on this assembly board paper and place it down on the face of the marquetry in one motion.  I then put the entire panel into the press, using a layer of 10mil plastic and a 1/2" piece of wallboard (Homosote or Celutex material at Home Depot) and a plywood board to distribute the pressure.

What this does is that, since I am using sawn veneers of slightly different thicknesses, my goal is to push all the material forward into the hot glue on the Kraft paper.  By pushing from the back (where the blue tape is temporarily holding everything in place,  the relative softness of the wallboard reaches into all the different pieces and pushes everything forward properly.

The nice thing about the blue tape is that it comes off even after being in the press.

Back of Panel on Kraft paper ready for mastic

Now the panel is ready for mastic.  That is the job for today.

1 comment:

Anonymous said...

hello Pat,
The clock you are making now , is that a copy of the one who is now for sale by Gerald E Marsh ? I wish I was now in America to see your clock for real .This is the most interesting post you have ever made so far and I guess you are going to need a lot of hammer veneering.Are you giving classes for hammer veneering ?I hope to see more pictures of the clock !I really do enjoy all your posts !Greetings ! Filip Tanghe from Belgium !