ALWAYS THINK SAFETY! Drill bits can shatter during use. Always wear safety glasses when operating power tools. Always disconnect power before changing drill bits.
Table Saw: 1/ Maintain concentration! 2/ Use a Riving Blade 3/ Use push sticks or feather boards 4/ Never place hands behind blade 5/ Wear goggles
Router or Radial Arm Saw: Always follow manufacturers safety guidelines.
Coffee Table Design and Construction Article Overview
This article describes how to design and build a large DIY coffee table, in cherry wood, with 4×4 legs and beveled glass panels on top. I strongly prefer furniture built from solid wood, and I seldom use plywood except for drawers. For years, I persevered with alder, which is a beautifully grained wood, but also a nightmare to stain. I then progressed to cherry, which is a beautiful wood, not hard on the tools, and can be nicely stained if prepared properly.
My house is an open plan, with a sizeable living room, and I wanted to design a coffee table that would compliment the room in both size and sublety. The final “as-built” dimensions are 44″ L x 44″ W x 18″ H. The following article is organized into a series of 15 step by step instructions that illustrate how to build the coffee table project as shown in the preceding pictures.
The article begins with Step 1 which describes how to construct the 4×4 leg work pieces, and concludes with Step 15 which describes how to prepare and apply stain to the finished coffee table.
At the outset, I would like to make a few comments about the various types of joint systems used to build cabinets and furniture. Some will argue this is just a sales pitch, and this is partly true, however it’s also my honest evaluation of these systems based on 40 years of woodworking experience, including extensive testing over the last 10-15 years.
I often make the comment: “I want to build furniture, not make joints”. Having said that, the end result has to be fast, accurate, strong and versatile.
In my opinion, none of the usual systems meet the forementioned criteria, with the exception of the multiple dowel arrangement. The multiple dowel system is the only system which in our tests has proven, over and over, to be stronger than the wood itself (oak).
The biscuit and pocket hole systems may be marginally quicker than the multiple dowel arrangement, however I personally wouldn’t use either system for furniture or cabinet construction. Someone once said to me: “A biscuit joint is better than nothing”. I can’t argue with that.
The mortise and tenon systems are excellent, but not quite as strong the the multiple dowel arrangement, and take an age to setup and complete. During construction of the dining chair. I mentioned the fact that it would be a nightmare constructing the chair, utilizing mortise and tenon joints. While that is absolutely true, I was not in any way demeaning the M & T method per se. The mortise and tenon is a classic system, but why would I take an hour to set up and complete an initial joint in mortise and tenon form, when I could complete a multiple dowel joint that is stronger, more accurate and takes about 3 to 4 minutes to finish?
Our tests reveal the loose tenon system attains approximately 50% of the strength of the multiple dowel arrangement. It’s not as accurate, and one system on the market retails in excess of $1000.00
We fully guarantee our system, and will refund the purchase price if any of the foregoing can be disproved.
Step 1) How to Construct the 4×4 Leg Work Pieces
I began with the four table legs. I could not locate 4 x 4 timbers, so I had to plane and join two 2″ x 4″ x 18″ cherry work pieces. Work on the mating faces and match the grain as close as possible. Lightly clamp the interface of the table leg joint as shown in photo, or the work pieces will skew sideways when clamped. I use the vise and clamp for alignment, and then use 3 – “C” clamps for clamping pressure.
After curing the work pieces, remove excess glue and square off all faces using the table saw. Final trimming of the legs can be undertaken in the planer. Ensure all sides are square. The work piece is too wide for the table saw, so carefully calibrate and set the miter saw to cut both ends. I used a digital caliper set at the back end to ensure all 4 legs are identical in length. Of course, you do not need to use turned legs for the design of this table, they can be left square section with possibly a routed external corner for added interest.
Step 2) Designing the Shape of the Turned Leg
Step 3) How to Turn the Legs in the Lathe
Determine lathe centres by criss-cross scribed lines to corners and use centre punch at intersection.
Some care is required or the leg work piece will run eccentrically when turning. Centre in lathe. Work piece is of considerable cross-section and weight, so ensure stock centres are firmly embedded! The leg pre-turned design dimensions are 3 1/2″ x 3 1/2″ x 18″. These can be altered to suit. Measure (from top) 6 1/2″ and scribe a line on all four faces. Undercut all four corners of the leg with fine tooth saw to prevent surface tear-out when using gouge.
Gouge turned area till all flats on surface are removed. Then mark all salient points of the table leg design, i.e. 1/2″ – 4 1/2″ – 2″ then 4 1/2″. Rotate lathe at slow speed, and continue marks around cylindrical periphery.
Video Part 1) Strength Test of the Leg to Rail Joint
Step 4) How to Design and Build the Main Outer Rails
Since I am going to add a trim to the lower edge of the rails, and since I want to dress the ends with the trim moulding attached, I add 1/16″ to each end i.e. 34 5/8″. I want to reference from the front face for the dowels and that is not possible with the trim installed, so I install Dowelmax and drill the 6 bores first. Reference from the top and front faces of the rail and leg, and drill through guides 1, 2, 4 & 5. Insert index pin through 1st guide and last bore. Then drill through guides 3 & 4.
Note: Since I have added 1/16″ to each end of the rail, I set the drill collar to 1 7/8″. When drilling of the four rails is complete, I began milling the sections which comprise the bottom trim. These are 8 in total, 4 are 1/4″ x 1 3/8″ x 35″ and 4 are 3/8″ x 1 1/2″ x 35″. Route one corner of four to 1/4″ radius, sand surfaces and glue to lower section of rail.
Second 4 spars are routed 1/4″ radius on two adjacent corners and a step is milled 1/8″ deep. Sand all surfaces and glue (brads) to lower edge as detailed.
The foregoing operation i.e. lower trim, can be simplified by the craftsman or eliminated altogether.
After joining the first moulding and before attaching the second, shave a miniscule section off the lower edge of the rail to provide a good square surface for the second moulding.
I glued the trim sections and used brads for the second sections, obviating extensive clamp use. Make sure the bull nose (second trim) is snug to the face of the first trim, before shooting brads. After the trim has been added and the glue cured, cut the ends of the rails. I used the table saw sled, and took approx. 1/16″ off each end. Remember all 4 rails have to be virtually identical in length, and the cuts must be absolutely square. Believe me, this saves a lot of aggravation when assembly takes place!
Step 5) How to Join the Outer Rails to the Legs
It would seem an appropriate time to complete the eight joints on the four legs. Set the legs vertically on the workbench, with the joint seam in the same direction. Leave a small gap between for marking the “check marks” and “X” s.
Video Part 2) How to Join the Outer Rails to the Legs
Step 6) How to Design and Build the Top
Mill the four outer work pieces, 7/8 x 4 1/2 x 46 inches. I cut my pieces from 7″ wide cherry planks. I have found that in some cases when, for example, reducing an eight inch wide work piece to a five inch work piece, stresses are relieved, which can cause the work piece to bow severely. To counteract that I leave 1/4″ extra on the cut. So in this case, I wanted to finish up with 4 1/2″. The initial cut was therefore 4 3/4″ . I then turned the board around continuously taking off 1/16″ each time, then finalizing with two cuts of 1/32″. The result was four true boards.
The design calls for four square bevelled glass panels which slot into the top boards. To accommodate the glass panels, recesses are cut into the upper inside corner of each top board. These measure 1/8″ deep and 1/4″ wide. This can be achieved by router or table saw. The router is quicker, but the table saw, in conjunction with the dado system, is not only a cleaner cut, but more accurate. I chose the latter. The cut is continuous on all four boards.
Step 7) Construction of the Frame Overlap for the Top
When I install the completed top over the lower framework, I like an overlap.
To achieve that, I sometimes use the table saw to undercut the lower face. However in this case I want to make the top look thicker (aesthetics), so I am going to add four 1/4″ x 1 7/16″ slats to the lower outer face of the top boards.
These are simply glued in position then the edges are trimmed in the table saw (note) when cutting the four slats, cut an extra piece of the same width. Section that slat into 12 small lengths and attach these to the underside of all four top boards.
These are utilized to hold the top boards absolutely level when cutting the miters. Before cutting the miters however, route the top outer edge of all four top boards (as and if required).
Step 8) How to Accurately Cut the Miters for the Top
Cut the miters. I use the table saw and miter guide for these cuts. The miter guide has an elongated attachment secured to it. The attachment measures roughly 1 3/4 x 1 3/4 x 14 inches, and provides a solid and stable base for mounting the top boards.
Set the miter guide to exactly 45°. Try two cuts on two mating work pieces. If “out” in a minimal sense, adjust miter guide to suit discrepancy. If the error is larger, split the adjustments between the two miters, otherwise the mating contours of the top boards will not line up!! To ensure that everything is true, make sure all top boards are the same length and the miters are as close to 45° as possible. The process is a bit like chess, easy to play, but difficult to get right.
I found the exact setting on the miter guide to create the almost perfect 90° at say the top left corner. I then repeated that process for the top right corner. Then using these same miter guide settings, I cut two of the four 45° miters. I then assembled the three top boards using two 90° clamp fixtures at the top finished joints. The next step was to ensure the two outer boards were absolutely parallel. To do that, I checked the inside distance top and bottom using the UTG, then adjusted as required using a pipe clamp at approximate mid section.
I then set a straight edge at the lower apex (45°s).
At this point the assumption is that the two lower 45°s right and left are close to perfect, so don’t touch these. Cut the left mitre and check, using the straight edge for guidance. Adjust the miter guide as required until a virtual perfect 90° is achieved. Repeat that process with the right lower joint. Adjust miter guide as necessary until the lower rail mates perfectly.
Carefully number all corners and then drill for accepting multiple dowels.
Step 9) Joining the Mitered Top
There are numerous ways to reference Dowelmax and after my first attempt, I decided to change my approach. Rather than referencing from the apex or outer point, I decided to reference Dowelmax from the inner recess of the top work piece.
This procedure allows for more accuracy at the inner glass recess and also obviates the use of the index pin. Clamp Dowelmax and drill through guides 3, 4 and 5.
Video Part 3) Joining the Mitered Table Top:
The following video shows me referencing from the apex, or outer point of the joint. I subsequently found it more accurate to reference from the inner recess as indicated in the preceding photograph. The principle is the same in either procedure.
Step 10) How to Glue the Table Top Assembly in Stages
Do not proceed before reading this guide: As a consequence of the axial direction of the dowels on the mitred joints, it is essential to begin by gluing two opposing “L” shapes.
While gluing the first two opposing corner joints, dry fit the dowels in the other two opposing joints. Close the whole assembly and clamp square. That method will ensure all four boards are true and square. I have four long clamps. I set two on the floor running parallel. Set the glued assembly on top, lightly clamp, then set two clamps on top, clamping in opposite direction. Tighten all clamps and ensure glued assembly is true and square. Repeat after application of glue to other two mitre joints.
Step 11) Design and Construction of the Coffee Table Center Underside Support Rail
The center underside support rail runs along the underside of the second and third table top glass support rails, as shown in Step 12. The main glass support rail does not use an underside support rail.
Dry fit all legs and rails (using two dowels for each joint). Clamp structure and ensure the assembly is true and square. On two opposing rails, measure from leg to centre of rail, draw vertical dotted line. From dotted line, measure out 1/2 inch and draw vertical full line.
Disassemble Dowelmax to guide block, add angle bracket. Clamp to work piece referencing to solid line and top of rail. (Ensure guides are centred directly over dotted line). Use 1-1/2 inch dowels and drill 1 inch+ into support rail and 1/2 inch+ into leg rail. Drill through guides 1, 2 and 3.
Note: With 3/4″ stock, adjust drill collar to drill only 5/8″ deep into face of outside rail. Then re-adjust collar, and drill 7/8″ deep into end of inner support rail. (For 1-1/2″ long dowels)
Step 12) Construction of the Inner Glass Support Rails
Prepare two boards 7/8 x 4 x 35-1/2 inches. One rail extends full width of top and should butt snugly into glass recess.
Begin with the long support rail; dress the ends until a snug fit is achieved, using the sled if possible. Then undercut the two ends to the point that when inserted, a snug fit is achieved and also the two top boards are level. Turn the board over and cut the two glass recesses (to the same depth as outer boards).
Insert the centre board, align and clamp. Follow the same procedure with the two short boards. Carefully centre the top long board, mark position internally. Remove and glue all surfaces. Install to marks, check and clamp. Repeat with two smaller boards.
Step 13) How to Sand the Coffee Table Top
My son recently bought me a 6 inch Bosch orbital sander which I love. Use your orbital sander for top, then sand all the edges by hand, paying particular attention to the profile at the corners. Try to avoid cross grain scratching at the corners, or these marks will be accentuated with the application of stain.
Step 14) How To Prepare and Stain the Components
My preference is to completely dismantle the dry fitted table and then prepare, stain and finish the various components separately. All pieces are sanded progressively 150 – 220 – 400 grit. The only wood I have found which does not need to be pre-treated (before stain application) is oak.
Prepare a mix of shellac and methyl hydrate in the proportion 1:2 respectively. Centre leg in lathe, coat liberally with mix and rub in. Finish off with lathe running at slow speed. Leave overnight.
I want a dark, rich colour, but with no blotching, so I apply Dark Walnut gel stain first, to give a good seal coat. Rub in, and remove excess. Rub with grain at flat surface when finished. Finish off with lathe running. Leave overnight.
I finished off with a coat of Espresso and Dark Walnut mixed in the proportion of 1:1 to enrich and darken the appearance. This procedure can be repeated to produce a darker shade, and a richer appearance.
One further advantage favouring sanding and finishing before assembly; if an error is made (as I did in this case), it is relatively straight forward to sand down the various components and start again.