Wednesday, January 13, 2010

Veneer, no apologies

Solid wood = top quality. NOT! Well, not necessarily, anyhow. It depends on the design, the veneer, and the workmanship. It's true that there is a lot of lousy veneered furniture, cellophane thin veneers used in places likely to receive wear or damage, cores of particle board or other materials assembled in ways that nearly guarantee early failure.

However, some of the finest furniture ever made was veneered, so it's possible. This desktop will be veneered AND it will be bomber! Here's a preview (from a later step fitting the end caps):




Makes me want to keep this desk too.

It starts with veneers that are much thicker than usual - between 1/16" and 3/32". At this dimension the veneers are stout enough to repel significant abuse but--and this is critical--thin enough to NOT act like solid wood once it's glued to the core. Thicker wood moves powerfully as it absorbs and loses moisture--which it does continually in response to humidity changes, even when finished--but centuries of experience has shown that veneers of this thickness can behave very well.

For most of furniture history "thick veneers" were the sole choice, as tools to economically produce thin veneer didn't exist. Veneer use was limited to the finest furniture because it was so laborious. These very thin "boards" were painstakingly hand-sawed out of the log, often by two man teams with one poor fellow down in a pit getting a sawdust shower. Thank God for big bandsaws today! I sawed the veneers a bit thick at ~1/8", knowing that the dull-ish bandsaw blade would cut unevenly and need a fair bit of clean up later, which would take the thickness down to target.

Next we want a quality core: flat, stable, able to hold fasteners strongly. This desk uses 3/4" Baltic birch, a super high-grade plywood that is tougher than many solid timbers. Before veneering I glued bands on all 4 edges, using cherry from the same plank as the veneers for the edges that would eventually show, and a less precious wood on the ends where it will be covered by the "bread-board" end caps.

After attaching the bands I carefully handplaned them flush with the plywood. Mmm, look at that cherry.




Here is the edgebanded top ready for trimming:



(The following day while setting up to trim on the table saw I managed to drop this assembly and a huge crosscut sled on myself while crawling underneath to adjust something--OUCH! Had to repair some dings too).

When the veneers go on they further lock in the edge bands, and the matching wood will look very clean and natural. Before going on, though, the bandsaw marks on the glue side of the veneer have to be smoothed. Most shops use a sander, but lacking that a handplane did the job:



Then plane perfect edges on the veneers in preparation to edge glue them to each other:



Changes in the weather affected humidity in the shop and the veneers didn't want to lay flat, but some weights pressed them into line. Planing with the plane riding on its side like this is called "shooting" an edge joint.

The veneers were then glued edge to edge ("clamped" with tightly stretched blue tape) to create a single thin sheet the size of the desk top. I had also prepared a set of veneers for the underside of the top, needed to balance the assembly to prevent warping. Since not everyone edge-glues veneers before pressing I decided to skip that step on the bottom veneers as an experiment, instead just taping them together with special veneer tape.

Finally it was time to press the whole assembly together with the vacuum press, essentially a super big ziplock attached to a vacuum pump; slip the glued up assembly in, seal the bag, turn on the pump, and marvel at how much force air can apply. The shop was a bit cold, so I put an electric blanket on top:



This was the dry run, so the bag closure rod is sitting on the right no yet in use. You can just see the grooved melamine sheet under the blanket edge, acting as a platen for the assembly, the grooves providing channels for the air to escape as the vacuum pump operates.

Having done a dry run I expected things to go smoothly, but the above mentioned experiment (not edge gluing the backer veneers) nearly resulted in catastrophe. Upon contact with glue the 4 backer pieces curled like potato chips and broke the veneer tape. In a panic I rejoined them with stronger blue tape, slapped the cherry veneer on the other side, taped the whole mess to maintain some alignment and zipped it into the bag as the backers tried to break loose again. The vacuum tamed it, but that was a close call. Had they curled just a bit more I would have had to scrape off the drying glue...it could easily have been a total loss. Good thing I didn't use a water based glue, which would normally be appropriate for a flat assembly but which would have caused even more violent warping than the Unibond 800.

Approximately 24 hours later you'd never guess the harrowing struggle; the veneered assembly came out of the bag flat as can be and has stayed that way ever since. This morning I detailed the front and back edges with shapes that attractive and comfortable to the touch, a task easier to do before the breadboard ends go on. The thick veneer shows another great virtue here--it's thick enough to allow shaping, whereas thin veneers lead to hard angular edges that are easily damaged.

This is a veneered piece that makes no excuses.

Tuesday, January 12, 2010

Desk job

I spent a lot of years behind a desk. This time it's different...not just behind, but in front, on all sides and angles, underneath, on top, inside out. After posting nothing but hiking pictures for months it's time to catch up with the shop, and the latest project is a desk for a good friend.

It started out in oak to match the other woods in the room, mostly plywood, two pedestals, eminently usable for the writing, photography work, and deep ruminations that go on at the tiny desk currently in place, but when Warren and Peggy came to pick oak boards from my stash a chance encounter with a cherry dresser triggered an avalanche of change.

It didn't hurt that I had planks like this hanging around the shop:


This plank is from an amazing tree that Dan at Horizon Woods told me about. It had two stems, each with nearly 40' of clear straight wood as much as 27" in diameter. Six logs of matching wood so nice you could have it for dessert--look at that color with no finish, steaming, or anything!

And this one, the instant choice for the desk top:




Cherry seemed to call for a more refined design--like this one, which just happened to be in the shop:




I designed this desk years ago before I had the skills to build it, and John Fisher (another College of the Redwoods grad) did a fine job making it. I am very excited to build it this time! The original drawings were not to be found, so the first order of work was to carefully measure and redraw the whole thing. Seemed slightly recursive to draw plans on the desk that is the subject of the plans.

Once the revised plans were approved it was time to make big pieces of wood into smaller ones. One big reason I like to order wood by the log comes into play now - I can select wood from different portions of the tree to control the grain orientation for the different parts. This first section of plank had nice legs at the outer edges where the rings run about 45 degrees to the faces, and drawer faces or panels from the center of the plank, a nice use for the more swirly flat grain found there.

I always feel butterflies cutting up nice wood--will the choices work well, will the wood move like crazy, will there be hidden defects? Here we go working out those commitment issues on the bandsaw:




Another round of sawing yielded a collection of roughly 1/8" thick veneers for the desk top. It was a major workout, as my big resaw blade was getting dull. Thankfully the heavy work had a nice payback: