Office Table |
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This Office Table will be constructed from cherry, very possibly curly cherry. It measures 30" high, 72" long and 30" wide. The top is 1" thick and will be edged with a very gentle curve to minimize pain from prolonged arm resting. The legs are tapered starting from 1 3/4" stock at the top and tapering to 1 1/8" at the bottom. There is one draw, 22 7/8" wide, 23" front to back and 2 1/4" deep. The legs and aprons are joined with mortise and tenon joinery and reinforced with pegs. The Drawer construction is traditional hand dovetail joinery with tapered floating bottoms. I have been wanting an office table for a number of years, but my list of projects for others has been so long that I haven't been able to sneak it in. An exploded view is shown at right. This is a rather simple project and shouldn't take long. Actually I have two quick projects I am going to sneak in before returning to my honey-do list. The other is a wall hanging cabinet which will house my hand tools. But don't tell anyone. If I get caught I'm in deep trouble. This piece will be finished with many coats of high gloss MinWax Wipe-On Poly because it will receive lots of wear. By the way, you may have noticed that I am now using SketchUp 6 to draw my plans instead of TurboCADTM Professional. I find SketchUp to be quicker, friendlier and much easier to texture. So, from now on my plans will be available in SketchUp native files, complete with dimensioning and texturing. You can download this one from my SketchUp Furniture Plans page. The first milling step in making the table is to mortise 3/8" by 4 1/2" mortises 1 1/8" deep. There are two per leg for a total of eight. These could be done by hand using a mallet and mortising chisel, or with a router, or even with a drill press and chisel. But the quickest way is to use a dedicated mortiser. This Powermatic mortiser has a table which can be finely positioned in two orthogonal directions; and the bit can be raised and lowered to plunge into the stock. In the picture above left I am using a 3/8" mortising bit. For those of you not familiar with a dedicated mortiser and bits, the bit is like a four sided chisel with a hole down the center for an auger bit. The auger removes most of the material while the four sided chisel produces a square hole. By moving the table in one direction and plunging the bit into the stock you can produce perfect mortises as shown at right. Some cleanup is needed and the chisel is the perfect tool for the job. The next step is to taper the legs. Most woodworkers taper their legs using a table saw and a tapering jig. I have also. However, I have always thought this technique to be rather dangerous. So now I draw the taper on one leg, set up an angled fence on my bandsaw (just a board clamped to the table) and rough cut the taper. Once the fence is set up you don't need to mark the remaining legs. Alternatively, you don't even need the fence if you can accurately follow a line by hand. Leave just enough for the drum sander to finish the job. For that purpose I use a poor man's taper jig that I construct with double sided sticky tape, two 3/4" by 2" pieces, and a flat surface such as plywood or particle board. As shown in the picture at left above, I use a table top that once was the extension table for a contractor's saw. It has served no useful purpose in my shop until this application. To keep the legs from flopping all around I tape them together with blue masking tape and then I run the whole setup through the Performax 22/44 Pro Drum Sander shown right. A side benefit of this technique is that the Performax both tapers and finish sands the legs. I have 220 grit paper in the machine for this operation. Other than breaking the edges there is nothing more that needs to be done to the legs before applying a finish. The drum sander is a very useful tool. I bring all of my stock to final dimension by making a few passes through it. Frame and panel doors or divided light doors can benefit from a few light passes to remove minor height differences in jointed material. Figured woods, which typically chip in the planer, can be finished with the drum sander and the chip out is simultaneously removed. The finished legs are shown at left. Note that the mortises are on the far face of the shared corner. They are positioned so that the apron is close to, but not on, the face of the leg. In this case they set back 3/16". This provides a nice shadow line from the leg to the apron. Legs are tapered largely for the esthetic value. But here is a thought provoking question. Is it possible that legs are smaller at the bottom to save material, but taper to the top to provide enough headroom for the tenons? Which came first, the chicken or the egg? All aprons have tenons on each end to match the mortises milled in the legs. The front apron has an opening for a drawer front. This opening can be created by gluing up four pieces to make the front apron, or by cutting a rectangular hole in the front. The latter has the advantage of preserving the grain pattern and showing no glue lines. This is the approach used here. To cut the square hole I first laid it out, then bored a hole near an inside opening edge with a forstner bit and the drill press. The hole is large enough to allow for turning a jig saw blade in any direction. I cut along the layout line getting as close as I dare without touching it. This is intended to be a rough cutout. See picture at right. Next I use a straight spiral patterning bit in my table top router to clean up the edges. Here is where double sided sticky tape (carpet tape) comes in handy. Using sticky tape I tape temporary guides to one long side and both ends. The bearings on the pattern bit will follow the guides and cut the edges perfectly clean, shown left. I then move the guides to the other long side and ends and complete the operation. The patterning bit leaves round corners which need to be squared up. This can be done with a very sharp chisel and mallet, or a flat flexible saw blade like those used to cut dowels at the surface. Squaring the corners might not be necessary if I were going to mount the drawer on metal slides, but I am going to trim the door opening with contrasting black walnut beading. After milling the tenons with the aid of a dado blade set and band saw, it is time for a dry fitting. Dry fitting, as shown at right, is important for several reasons. First, it allows for testing the fit of the joinery. Mortise and tenons should fit rather tight but still go together and come apart, with at most, gentle taps of a dead blow. Any tighter and you risk splitting. Second, dry fitting is the time I use to figure out my gluing and clamping strategy. I go through all the steps I will use to glue, clamp and clean up. This forces me to have all my tools out and ready. Lastly, I use this time to estimate how long the glue up will take, which drives decisions such as: do I need the aid of another person, should I use Extend glue for longer working time or in which order should I put pieces together. In this case I decided to glue up in two steps. First I glued the legs to the end aprons and left them to set up. Then I proceeded to glue the front and back apron to the legs. Even so, because of the length of the table I needed help to finish the glue up. The drawer needs a frame work to hold it in place and guide it as it travels in and out. This structure is similar to I beams and in fact adds a great deal of strength to the table. As shown in the picture above left the drawer guides are held in place with pocket hole joinery. The pocket holes are drilled at the exact angle needed to allow a special screw to tow the boards together and get maximum depth into the front apron without punching through. At the same time the pocket hoes are drilled, so too is a pilot hole for the screw. This is all accomplished thanks to a special jig and bit made by Kreg. Glue can be used to add strength to the pocket hole joinery, but because this is an end grain to face grain joint it does not provide a lot of strength. Instead I chose to use angle braces shown in the picture at right. Notice the angle brace on the outside of the apron. That is held in place with double sided sticky tape and provides the opposite surface for clamping as shown left. Double sided sticky tape (or carpet tape as it is known in the trade) has many uses in the shop. I keep a number of rolls of varying width on hand. Occasionally the tape will leave a residue on the wood surface. Do not panic, it can easily be removed with a cloth and mineral spirits, and mineral spirits will not harm the wood. The angle braces in the front pose another clamping problem. The hole in the front leaves no place to tape braces on the opposite side. But this is actually a more common situation for which there is a commercial solution. The clamp faces of the Quick-Grip Bar Clamps can be fitted with attachments of all sorts. The attachment shown left is perfect for the clamping situation we have here. Simply remove the yellow pad and replace it with the corner attachment and we are good to go. See picture below right. This angle brace will add all the strength this joint will need. But there is one concern. Notice that the angle brace and the apron are a cross grain situation. Any time cross grain appears in a glue joint it demands attention. In this case the apron is about five inches wide; the analysis I performed, with the aid of a moisture meter and software program, assured me that this will not be a problem. If it were to be a problem I could have used two shorter braces with a small gap in the middle and that would have solved it. Cutting these corner braces would be a pain if I didn't have the perfect tool. The braces are 2" by 2" on the right angle sides. To cut them I simply tilted my band saw table to 45 degrees as shown in the picture at left. Notice by moving the fence to the right it doubles as a fixture to hold the stock from falling off the table. Attaching the table top to the table also demands attention to seasonal changes. Since the top is wide, approximately 30", with the grain running lengthwise, we can expect its width will change rather dramatically over an entire season. My analysis says it will change by 15/32" in the western part of Massachusetts, where it will reside. To allow for this expansion/contraction I use two types of fasteners. One type is shown right above. It looks like a figure eight and has two holes for screws. The fastener is let into the apron the same depth as the thickness of the fastener with a forstner bit. Click on the picture for an enlargement to see how the whole is opened to the front and sides to allow the fastener to move laterally. The fastener is screwed to the apron from above, and when the top is added, screwed to it from below. These fasteners I use on the end aprons because the relief motion is ideally suited, and because there is room inside the corner braces to fit them. On the fronts I use a biscuit jointer to cut a slot and use metal clips that hold the top down while still allowing it to move. In the picture at left you can see the drawer structure clamped and waiting for the glue to set up. On Chiefwoodworker's Blog I posted an article on The Design & Construction of a Traditional Drawer. Here I describe the crafting of a traditional drawer. I'll start with the bottom. This office table's drawer is rather wide, deep and shallow. The bottom of the drawer is almost 24" square. If I used a three piece glue-up to construct it, each piece would be a minimum of 8". Since my jointer is only 8" I decided on a six piece glue-up, each piece approximately 4 1/2". I first glued up three pairs of two boards to get three pieces approximately 9" wide. The picture at right shows these three pairs sitting side by side. If you look closely (click to enlarge the picture) you can see these pairs are not yet joined. I like to mark triangles with a carpenter's crayon to remind me how I plan to join boards. Before applying glue and clamps, the edges have first to be prepared. Three conditions are important to achieve a joint stronger than the surrounding stock. First the edges must be recently jointed or planed so that surface oils from the wood, or dirt from the environment, are removed. Second, the edges must be in the same plane, i.e. coplanar. That means that each edge must meet the other at all points of their respective surfaces. This doesn't require that both edges are square, but they should be very close. Third, you must use the appropriate glue and maintain the appropriate temperature for curing. To assure condition three is met I use Titebond Original for most applications; Extend when I need more time, or Type III when moisture is an issue. My shop is heated so temperature is always well within the curing range. To assure condition one I plane my edges just prior to glue-up. I never rely on recently sawed or joined edges. In my opinion the best joint requires planed edges. Edges planed just prior to glue-up plays right into assuring condition two, that is, to be sure both edges are coplanar. To do this I mark boards to be joined as shown above right. Then I fold two boards together, the two that form the joint, such that the marked sides are facing each other. I align the edges as best I can and clamp them together. Next I put the sandwich in a vice and plane the pair of edges that are to be joined as shown at left. It is possible that, if not careful, the edges will be planed slightly out of square. But that will not matter if they were folded correctly. It is akin to a board that is ripped along its length with the table saw blade set a little off ninety degrees. If you put that joint back together with the edges joined as they were cut there will be no gaps. The same is true when you fold and plane. The edges do have to be straight, or flat. Shown right above I check the for flatness using a straight edge. After all joints are treated the same way I can apply glue, bring the panel together according to my markings, and apply clamping pressure. The final panel is shown at left, waiting for the glue to cure. The manufacturer says that glued pieces can be worked after just one hour of curing. I always let them sit overnight because I don't want to risk stressing which may weaken the joint. A few additional comments about glue-ups. I don't use biscuits. I don't believe they add strength, in fact may reduce joint strength. I have never been able to achieve alignment as well with biscuits as I can by carefully hand aligning and tightening the clamps. But I also leave my stock 1/16" to 1/8" thicker than final, and use my PerformaxPro 22 - 44 Drum Sander to bring the glue-up to final thickness as shown at right. Notice that the panel hangs over the side of the drum sander, about 2" in this case. I can flip the panel on alternate passes, effectively providing capacity for a 44" panel. This comes in handy, especially for wide panels and figured woods. A traditional planer often will leave figured stock with tear outs. Not the drum sander. This machine is worth its weight in gold. When I have completed milling all drawer pieces to size I have five parts; a back, two sides, front and bottom as shown left. The next step is to mark the back, sides and front for dovetailing. I start by marking the ends with the thickness of the mating parts. The back and sides are 1/2". The front is 3/4" thick. However, the tails that will mate with it are blind tails and therefore only set in 1/2". This allows me to set the marking gauge to 1/2" and leave it that way for the marking of all pieces. Shown right I am marking the end of a side. By the way, here is a tip about setting the marking gauge. One you set it, leave it set until after glue-up. You will be surprised how often you put the gauge away only to discover you missed one mark up. Then you have to match the original setting risking a slightly different setting. The marking gauge I use has a round blade that is beveled toward the depth gauge side. This tends to force the depth gauge tight to the board and produces a clean straight mark. In addition, the mark is cut across the grain and is deep enough to provide a guide for chiseling as will be seen later. A close up of the gauge and its resultant mark can be seen below left. Next I mark the tails. There is a lot written and debated about whether to mark tails or pins first. You can read all this material and join in the debate, but in the end all that matters is what works best for you. I am a tails first guy. Don't ask me to justify it with facts or reason. I just prefer it. With a pencil I mark off a half pin on each end of the side's end. Enlarge the picture at right to see the two half pin lines 1/4" in from each end. Next, I use a divider and through trial & adjustment I set it such that when I gently step it across the board (leaving no marks), starting at a half pin mark, it ends even with the other edge, shown at left below. In this case, because the drawer is so shallow, it only takes one step. If the drawer were wider I would decide how many tails I wanted and adjust the divider such that the last step still ended at the edge. The divider setting that satisfies this condition turns out to be the width of one tail and one pin. After I have the divider properly adjusted I again walk it across the board but this time apply pressure to mark the board. I must walk it from both half pin marks to complete the marking. Using a dovetail marking tool (not shown) I complete the marking shown right. Notice the two small holes created by the divider. I can place my pencil in these holes, slide the dovetail marking tool up against it and draw lines across and down the side. I am careful to stop the vertical line at the horizontal mark left by the marking gauge. If I am sloppy and extend this line beyond the horizontal mark I am apt to follow it with the saw. Note I mark the waste areas with an X. No matter how accomplished one gets cutting dovetails this step should never be eliminated. It is too easy to cut away the wrong piece if not reminded by these marks. The picture at left shows how the tail cuts are made using a dovetail saw. I prefer a western style dovetail saw with a rigid back. I have tried Japanese Dozuki Saws and like how easily they start, and how quickly they cut. But I just feel more in control with a Lie-Nielsen 15 ppi Dovetail Saw. The most important parts of this cut is to cut exactly perpendicular to the face of the board and to stop at the horizontal marking gauge line. Try to follow the vertical line exactly, but if you don't it is not a real problem; these tails will be used as a mask and copied onto the pin board, hence the error will be self correcting. I use a fret saw to remove the majority of the waste. I cut as close to the horizontal line as I dear making sure to leave enough material so that the marking gauge line can guide my chisel. This is where the Xs marking the waste comes in. If you have lots of tails, as you would in say a six board chest, it is awfully easy to be cutting along and inadvertently cut a tail off. That ruins the whole piece. Next I use a sharp chisel to clean up the waste, shown left. This can be a tedious step if you have a lot of tails, but in this case there is only one clean up per end. This task is made much easier if your chisel is very sharp. I like to sharpen mine just prior to use and several time through a project if I have a lot of work. The sharpening is easy and quick. It also affords you a break from chiseling. When the tails are complete on both ends of each side I use them as a mask to mark the pins on the front and back. I then use a similar process to craft the pins. Completed tails and pins can be seen at right. Note the pencil lines on the edges of the pins on the top board. Since the tails were used as a mask I cut the pins such that I just leave the pencil lines. This will assure a snug fit. Also note how perpendicular the tail ends are to the face. This is very important. Perhaps one of the most important tools in the shop is the coffee cup, full of hot coffee, shown above right. This tool is essential when hand cutting dovetails. It calms the nerves and steadies the hand. I use whole bean Eight O'clock coffee and grind it fresh. The most difficult of dovetails is the half blind dovetail - the socket that is. The tails are used as a mask. The dovetail saw is used to cut the side of the socket, which is a compound cut because you must hold the saw forty-five degrees to the end and eight degrees to the sides. This provides only a partial cut of the socket side. The rest is done with the chisel. The completed half blind dovetail is shown above right. Notice you can still see the marking gauge scribe lines. Most cabinetmakers leave these lines as a signature of hand dovetails. The completed pins can be seen in the picture at left. Notice that the pencil marks can still be seen on the edge of the pins. Leaving these lines provided a nice snug fit. Not so tight as to cause splitting and not so loose as to leave gaps. Finally, a view of the finished through dovetails, including the beveled and notched bottom is shown in the picture at right. In this picture you can see how the beveled bottom rests in the dado and touches at only one point all along its edge, decreasing friction and binding so that the bottom can expand and contract freely. In fact you can see that the bottom has already expanded somewhat in the recent humid hot weather. Also shown in the picture at right above is a notch in the center of the beveled bottom. After the final finish has been applied and dried I will drive a screw and flat washer through the grove and into the back, tightening it just enough to support the wide bottom, but not so tight as to impede expansion and contraction. The table top is an exercise in large panel glue-up. Since this top is 30" W x 72" L, extra care must be taken to plane and thickness the boards so that the desired final thickness can be achieved. This is substantially more difficult when each piece is 6' long. My starting material had a fair amount of twist, warp and bow. Still I was able to achieve 3/4" final thickness in all pieces except one, which had a small area of remaining rough sawyer cuts shown right. I simply placed this board such that the "flaw" was on the bottom. It actually adds to the piece. Two hundred years from now an antique dealer will point this out to a customer as proof that this is a hand made piece. The top is fastened to the table with clips and figure eight shaped fasteners designed to allow expansion and contraction as the temperature and humidity change with the seasons. This prevents wood splitting and joint failure due to the forces that would otherwise be exerted by these seasonal changes. The stock for this top was part of a load I bought from a sawyer who supplied lumber to pallet makers. To him this was junk wood. I purchased it for $1.50 per bf. Warp, twist and bow notwithstanding, you can see from the picture at left that this is highly figured tiger maple. Figured maple is traditionally stained a reddish brown color to make the figure pop out. However, I wanted all species of this piece to show their natural beauty, so I finished it with a clear finish. Figured maple was also used in the drawer construction; tiger maple for the sides and back and blistered maple for the drawer front. The drawer front was contrasted to the cherry with the aid of a black walnut bead surrounding the drawer opening. The finished table, shown right, is a blend of four wood species and five wood grain figures. There are seven coats of finish (and perhaps more to come) to provide for the abuse it is likely to take in an office environment. The drawer provides space for an organizer and other necessary office supplies and tools. All in all this was a challenging project, but one that will serve me well for years to come. I think this piece will definitely be fought over by my children, once I have gone to the bigger workshop in the sky.
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