Sunday, June 6, 2010

The 'Small' Table ... 20' x 8'

Well, after a rainy weekend, during which I got to catch up on some emails, drawings, bookkeeping, (ugh), shopping, and reading, I've actually got a minute to do a little writing here. May was quite a month, with two show openings, Open Studio, some smaller projects, and work on two big tables, which, if you could find a place to put them end to end, would stretch 46' from one end to the other .... Lots of cnc files, (like, probably more than 100), lots of engineering and problem solving, lots of mdf and lots and lots of moving parts around, some of them 3cm thick and solid granite ... Click the photos to enlarge them ...
We've had to move most of the work now to my 28'x 30' garage, where they just barely fit side by side ... In the foreground is the working base, made from Timberstrand, which allows us to work on both the bases and the tops in our separate shops ...
Surprisingly, one of the unexpected problems was swelling mdf ! We tend to think of mdf as a totally stable, man made, inert material, which was one of the reasons we chose it for the substrate .... Turns out, over 48", mdf can expand by as much as 1/16th of an inch as humidity rises and moisture is absorbed ... It doesn;t sound like much until you consider that the solid wood edging expands in width, but not in length, so molding pieces that once butted tightly together no longer fit quite so tightly together. Our solution was to take off the moldings and joint the sections (that's the smallest section of all of them in the photo above), so that the cherry now touches, but the mdf doesn't. No problem, as the substrate is covered with granite and other, curly maple veneered panels.
Thursday last week, for the first time, we set up the completed base for the 20' table in Steve's shop, after disconnecting a few tools and dismantling some of his dust collection system. The open center sections are for electrical access and will later be closed in with veneered panels held in place by super magnets.
Next, we added the steel. The entire outside two feet of both tables is Canadian, 3cm thick granite, at approximately 150 lbs per piece, hanging out there in space. There are 18 24" wide pieces in the 26' table and 12 24" wide pieces in the 20' table ... The substrate, with it's cherry moldings, is bolted to the steel. After load testing, we decided on 2.5" x 1.5" rectangular tubing with 1/4" walls. Those pieces are of diminishing lengths to follow the curve of the tops of the tables and 8" less in width than the table at all points.... They were cut on a sharp, 67.5 degree angle, drilled, tapped and capped by Sam.
In Steve's shop, we were able to assemble the sections temporarily on their permanent base to be sure that once the table is finished and assembled on site, everything will fit together smoothly.
That's Steve Holman in the center (it's actually his project and we're just the 'helpers'), his assistant Kevin is on the left above, and Trevor, my cnc guy, is on the right. Trevor has done an amazing job figuring out how to cut all this stuff, including the solid wood edges, bolt holes, holes for the electricals, and the granite patterns on our (second floor) cnc. It's been a lot of hauling....
Trevor was at Steve's shop to deliver the 'outriggers', the pieces that hold the steel supports for the 26' table, which we will test assemble in my garage when that base is completed, later this week. After we checked the granite templates for the 20 footer, we disassembled everything and Steve will start the finishing process on that base this week as he finishes up construction of the base for the 26' table.
I then drove to Proctor to deliver the templates for the small table to Herb Johnson at Johnson Marble, and got a little education on granite cutting. The straight lines are cut using a beam saw that appears to be from an earlier era, but still chugging along fine ... The templates are traced onto the slabs of granite with a scribe, and the straight cuts are lined up with a laser that is 'pretty accurate' but checked after setting with the actual blade of the saw before they are cut. Then, Herb's assistant, believe it or not, cuts the curves freehand with a diamond blade on a right angle grinder, a truly Olympic display of hand eye coordination. He says he's been doing it that way 'for a long time' and it is amazing to see how the finished granite pieces fit against the curved cherry moldings. By the way, the miters, which are about 30+ inches long fit as well as the templates. Herb told us that we did 'the hard part' by making the templates .... well ... maybe ....
While I was dropping off mitered end templates for the 'small table' I was also picking up the cut pieces for the 26' table and we now have 10 of the 16 pieces in place. After some truly small adjustments to the 6 center templates, they will go to Herb when we pick up the 6 mitered granite pieces for the 20' table ...
The 20' table with it's missing end templates is now assembled on the working base in my garage, next to the 26' and my convertible is out in the rain. The center mdf panels for both tables will be final fitted after we have all the granite and then veneered and finished in Steve's shop.
The granite is beveled and raised about 3/16ths above the cherry moldings and the center sections. I wish I had taken this photo looking down the miter as the fit (all of them so far), is perfect ... The granite has these wonderful blue flecks in the right light, but reads mostly as black ... More later in the week I hope .... Two other posts HERE and HERE ...

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