I am making these for a friend of mine who has a very specific idea when it comes to his DVD collection.
The pair of DVD towers are made completely from 3/4 solid oak. The original idea was to make them with box joint and finish them with natural oil finish to show off the wood grains and joinery, but he changed his mind before the wood got cut, and now the color would be satin black finish to match the rest of his furniture, so the joinery method changed from box joint to Festool Domino in the last minute.
Step 1: Design and Materials
These particular DVD towers are somewhat modular. Every box can be altered one to another except the two top boxes, which will not have the domino slots on the upper section. Each one can be an individual storage box or a carrier on it's own if the owner decides to take part of the DVD collection somewhere.
My friend didn't want to buy something from the store because they are all the same rectangular shape and look all like a cabinet, somehow he found a picture one day, showed me on his phone and asked me if I could design something like that. So technically, I've seen it once - thus it's not my design, but we could not find it anymore when we went back to look. This is just a build based on what I remembered out of one picture, and adding some features to make it more modular.
A DVD case was measured, and then I came up with the box dimension. The critical dimension should be the inside cavity height and depth of the box, which in this case 7 3/4" high and 5 1/2" deep, so that the all DVD cases will fit into the box with about 1/4" room to spare. (Note: The drawing showed the box was 5 1/2", that was not correct total depth of them. We should add 1/4" to 5 3/4" depth allowed for the backer strip thickness, so that we can keep the inside cavity at 5 1/2").
I had some 3/4" material so I made a couple of prototype boxes to see if all the dimension worked out OK, then went to the local lumber yard and bought about 25 bf of red oak rough lumber.
Step 2: Milling to Final Size
The rough sawn red oak lumber from local lumber yard went through the planner for smooth 2S process, then they were cut using circular saw with straight guide so that one side of the lumber was straight - straight line ripping. This is the alternative way of using joiner machine.
The next step was to cut the lumber into the right length with a fine tuned miter saw or a cross cut sled on table saw. A stop block was used at 12" from the blade for cutting the longer pieces, and an additional 4 1/4" spacer might be needed for the shorter pieces, in order to get two length of the stocks all at the same dimension for each box. Also, it's a good idea to have each box come from the same piece of lumber so that they move in the same manner with humidity change. The final length will be 12" and 7 3/4", it's better to number each piece as well as picking out the outside surface of each board (especially important if the natural finish will be applied), and then they were trimmed into the same width of 5 3/4" with table saw. (See note in previous step)
After the trimming process, the Festool Domino was used to cut two slots at each end of the shorter stock for joinery. This can be done by using dowels or biscuit joiner. The rule of thumb in my work flow would be to use dominos for any end grain joint (like solid wood boxes or cabinets where it needs more structural strength), and use biscuits for long grain to long grain joint just for alignment purpose (as join two boards together to make a wider board). This process can be vary from each individual person, as long as it achieve the same goal, all ten boxes should be build identical.
All of the 7 3/4" vertical pieces will need additional notch on the back side for gluing the back strip, in order to keep the DVD from falling out of the box, an old fashion small table saw sled was used with a flat bottom teeth blade on the table saw.
Two of the tower bases were just two boards glued together and trim cut to make them 14" wide and 17" long. Two of the molding pieces were added at the bottom of each base to add more stability and some interesting lines.
The connecting brackets were 3/4" x 1.5" x 10", ends were cut 45 degree just for the appearance.
Step 3: Glue Up and Final Sanding
Run a dry fit before glue all the boxes together. All inner surfaces were sanded using 80, 100 and 150 grid sand paper before the boxes got glued together.
3 boxes were then glued together at a time, just make sure to have a wet rag within the reach to wipe off the excessive glue, at least for inside corners.
After glue set for an hour, fit the back strips individually and glue them on. Leave about 1/16" longer at each end in case it shift during the glue up, and the excessive material will be flush trimmed with router or sanded off later on during the final sanding process.
Finial sanding took some time. Starting with 80 grid to sand everything flush, and 100, 150 to 220 grid to finish. Some pencil marks could be very helpful to see the sanding progress, so that you don't try to sand your brain out...
The sanding schedule is very important, if a high quality finish is absolutely required, do not skip lower grid, it maybe possible to skip higher grid (in this case, 120 and 180). These wood has been through a planer, so it would be reasonable to start with 80 grid to scratch the surface in order to even out the planer knife marks, if started with rough lumber from the mill, a 60 grid or even a 40 grid paper might be needed. If one working with sanded plywood, the proper schedule would be recommended as 80, 120, 180, 240 (optional) or 100, 150, 220.
The plan was using the water base stain, so the final sanding grid should be 220, if the plan were to have the oil base stain, somewhere in 150 to 180 grid would be enough.
One of the tricks to sand later to be stained wood surface is to wipe all surfaces with wet rag to raise the wood grain in between each grid change, then sand it down with the next grid. It will help to cut down the sand effort of next grid, and sanding required after the stain is applied.
Some 220 grid sanding blocks were used to knock out all the sharp corners along all edges, it seems this detailed process took forever to complete...
You can really see some beautiful oak wood grain after final sanding! It's very soft to touch with knocked off corners, yet the wood itself is very dense and hard.
Step 4: Finishing the Boxes
General Finishes water base black stain applied twice, light sanding with 500 grid after stain dried to smooth out the raised grain.
General Finishes water base High Performance satin top coat, applied three coats, and sand after first coat with 500 grid sand paper.
Finish process is very important, it requires patient and attention to details. A so-so project can be really great if the finish is right, but a great build can be a disaster if the finishing process is bad. Oak or some other open grain wood does not require a pre-stain coat (shellac or sanding sealer), but pine, maple, and birch will do for sure, as they are "blotchy" - the stain will create un-even color on the wood surface that looks like someone dump the ink on the wood - see one of the picture, it's the pine board without a pre-stain coat.
The last step is to create the supporting brackets between the base and bottom box. Assemble two boxes together, lay them flat on the workbench, use a protractor and measure the angle between the table top and edge of the box, and that would be the exact angle needed.
The tower has to stand vertically and balanced. The process above is one way to find out the adequate angle. In this case it was 27 degree. Go to miter saw and set up the miter angle at 27 degree and cut once, turn the angle back to 90 degree and cut another piece.
Do not worry about the length of the cut too much, because we have to make the final cut again after we have all four pieces together. Clamp all 4 pieces together, making sure the bottom side and angle side are flush on all of them, and make two more cut at the tip of the angle and opposite side of the angle, and now we have all 4 identical pieces.
Use the same procedure to cut slots on the supporting brackets, and attached them to the base with screws after finish them in black. Use felts on the bottom of the base to protect the floor. We are now finished.
The knock-down mechanism was made from two sets of dominos, really two sets of wood dowels will work the same way. They have to be cut precisely in order to work properly, so detailed set up (no free hand drilling here) and woodworker's patient are required.
The DVD towers are then delivered to the location. Mission accomplished.