|Forum topic by Mark A. DeCou||posted 10-12-2006 05:25 PM||34203 views||11 times favorited||14 replies|
10-12-2006 05:25 PM
I have to admit that I am a stubborn guy in a lot of ways. Ok, maybe most ways.
First I’m short of the Capital I need to run a small business and buy tools I need, and I won’t borrow money. I also live in a remote place because I would rather hear coyotes than a neighbor’s yapping mutts. However, this quiet country-life requires a lot of driving time to reach a subcontractor’s shop. More importantly, because I am stubborn, I don’t like to tell customers that I didn’t do all of the work myself, so I don’t want to use subcontractors if there is anyway to avoid it. In addition, my customers tell me that they want to buy my work, not my management of other people’s work.
Add to that, the fact that I enjoy making things that are difficult for my skill level to build, stretching my abilities to the breaking point. I like to get to the point that I almost want to quit, then I enjoy the feeling of accomplishment when I have pushed through the difficulty.
From all of that stubborness, I create for myself a lot of opportunities to figure out new work methods to tackle new problems. Maybe not “new” to the world of woodworking, but surely “new” to me.
This past Spring, I agreed to build a large slab book-matched table top and base for a family. Quite frankly, I didn’t have any idea how to do it, but I was too stubborn to say “no.” The challenge of learning something new sounded exciting at the time.
I knew that I would need two slabs off of the middle of a tree trunk that were thicker than 2”, wider than 24” wide, and longer than 96”, and so I worked with my Lumber Mill Expert Sam Kellogg in Garden Plaine, KS to select a log, get the wood cut, and to start the drying process. If I had the money, I would have my own lumber winch truck, my own lumber mill, my own tractor, and my own kiln, but Sam does a great job helping me cover my obvious shortfalls in equipment. Sam also builds wonderful kitchen cabinets and furniture, so my visits give us a chance to discuss the state of woodworking in Kansas, which would almost be reason enough to make it over to his place once in awhile, about a 2 hour drive.
Now, even a guy as “slow” in the mind as I am can tell that my 12” Grizzly jointer http://www.grizzly.com/products/g9860zx is too small for a 24” wide board. And, my 12” DeWalt surface planer wouldn’t work either. So, I went back home to figure out a set of dependable work methods that would insure a quality piece of furniture.
Sure, I knew all the basic woodworking steps, but I have never before faced having to do joinery on hunks of wood that are heavier than I can turn over by myself, and are wider than any of my “big” shop power tools can help me with. I found myself in a pickle, so to speak, and too stubborn to call it all off.
I knew that I could hand plane the surfaces, but my customer’s cost budget on this project required me to move along just as fast as my big mitts could work, so I looked for a faster, more flat method.
Sure, I could have called around and found someone with a large wide-belt sander that could take the slabs and make them smooth, but where is the challenge in that? Also, I could have gotten my credit card out and ordered a wide-belt sander from Grizzly, but where would I put it? And I don’t like credit.
So, my first idea was to buy George Nakashima’s book “The Soul of A Tree,” figuring that surely in his book, he would explain the methods. I ordered the book used from www.amazon.com, and when it came, spent each night before bed reading it.
I learned a lot reading the book, but unfortunately, it didn’t help me one bit on how to make the table top. None of the photos offered any clues, other than George sitting beside a couple of large boards resting on saw horses, adn I had already thought of that.
So, I kept thinking through the process while the boards were being dried. My “study” sure gave me a deep appreciation for anyone that does large slab-top work. In the past, I didn’t think it was so difficult, but now I know better.
I decided the best thing to do was to practice a little on a smaller table top, something I could make a coffee table with, in the Nakashima-Inspired style. I thought I would use the coffee table to hone the techniques with a more manageable sized board, and move onto the Dining Table slab top after I knew what to do. Sam Kellogg had given me a slab of Kansas Sycamore in a previous trip to his place, so I decided to start with that. It was 2.75” thick, 24” wide, and 80” long, perfect for making a coffee table.
In the past, before I had my Grizzly 12” wide jointer, I used my Legacy Ornamental Woodworking Mill www.legacywoodworking.com to flat-mill smaller boards, the kind that are 6”-10” wide 48” long. So, using that concept, I was thinking that if I could make a set of perfectly flat rails that were 24” apart, with a table that would hold the large slab top wood perfectly stable, I could make it work.
The Legacy Mill has a table rail system that moves up a down, which would be too complicated for me to try, so I decided to make removable rail shims from strips of 3/4” MDF, to be able to adjust the height, depending on the board. I decided to press ahead with the concept and worry about how to make a straight glue joint down the middle of the book-matched table later (more on that in another discussion), and headed to get some MDF to build the sliding router rail system.
I don’t ever like to take time to draw out plans, I already have the “picture” of what I want in my mind, and so any drawings I do are for communicating to customers, or for documenting what I did. I sometimes will make a quick napkin sketch, but this usually only includes details of the design, or joinery details that I am having difficulty picturing only in my mind. I figured in my mind that 2 sheets of MDF would be enough, so I bought three sheets. I ended up using almost all of the three sheets. Since I don’t do math real well in my head, I tend to always buy more than I think I need, and only occasionally do I run out in the middle of a project step. From where I live, running back to the store is pretty costly, so I try to error on the side of getting more than I think I will need.
I have built “Torsion Box” support bases before, as I use them underneath all of the furniture pieces while I am building them. I have a very crooked concrete floor (see my “workshop” page) and so I build torsion boxes as the building base of each piece, and so over time, I have accumulated several sizes of them. What I am always amazed at, is how stiff they are, as the torsion box construction takes out any twisting, to make a really flat work area. If I had a bigger shop, I would make a huge torsion box, and call it my assembly table, but for now, I just build one a little bigger than each piece of furniture, and then store it in my old barn when I am not using it.
Here is a picture of the torsion box construction, with the side rails, before I have glued in place the top sheet covering up the interior skeleton. The distance between the rails is 24”, and it is 96” long. I used three sheets of 3/4” MDF to build the system.
This next photo shows the router rail, with my Porter Cable router mounted on it. Notice the strips of MDF on the top of the router rails. I can add, or remove strips depending on the depth of cut I need for the set up.
This is my second Porter Cable 3.25HP router. The first one I burned up trying to take too deep of a pass over and over again with a 2” diameter bottom cutting flat bit. I take lighter passes with my new router, and I use a 1.5” diameter bit now. I also took out the after market quick change bit holder that I used, as it introduced just enough vibration to wear on the bearings and help with the demise of the first router. Ugh! Nothing $300 can’t fix though. If you want the least expensive place in the world to retail purchase a router of this brand and quality, check out the Legacy Woodworking folks, they sell them with their Ornamental Milling machines, and they are the least expensive I could find on the internet. They also shipped the day that I ordered it.
I lay the rough board on the table, shim it where necessary to get as staight a level line through the whole board as best as I can “eyeball.” Then, I use a bottom cutting bit I bought from Magnate www.magnate.net and methodically push the router-sled back and forth until I have made an entire pass across the whole surface. Then I lower the bit about 1/8” per pass, and then do another shaving of the whole surface, and so on, until I get the final thickness that I am after.
After the top is flat, I can turn over the board, re-shim it by using a digital caliper to insure that the distance from the router sled to the “bottom” flat cut side is the same all over the board. Then, I repeat the routering process until the parallel face has been milled.
When I am finished, I found that the variation in thickness measured with a digital caliper (those dialed ones confuse me) around the whole edge of the finished board was between 0.001”-0.003” in variance, and I figured that it was close enough. Careful surfacing and preparation of the two rail boards is essential to keep the two sides parallel in the finished product.
What I ended up with was a suitable method for flattening wide boads, facing both sides, and making table tops that are at least 24” wide from a single board. For a larger board, I would need to build a larger torsion box and sled system.
One side note: I did learn the hard way that the free Kansas Sycamore slab of wood had 5 nails hidden in it, so I check for signs of nails better from now on. Hitting the nails didn’t even nick the carbide on the Magnate bit, but it was still a gut-wrenching feeling hitting a nail only after 15 minutes of work with my brand new bit. I searched carefully after that and found the other four nails before I hit them with the router bit.
I hope that this idea helps some other folks that have limited space and tools. Below I posted a photo of the Coffee Table, and also of the finished Dining Table.
At the Western Design Conference in Cody where I showed this dining table, I continually answered questions on how the “floating bread board end” with wood pegs was built and assembled, but that will be the topic of another lesson I am working on. The key for me is to remember to take step-by-step photos so that I can explain it later, which is sometimes hard to remember in the rush of working on a project, and the mail delivering everyday more bills to pay.
thanks for listening, I will enjoy hearing your comments, or better ideas,
-- Mark DeCou - American Contemporary Craft Artisan - www.decoustudio.com