Entertainment Center Console Construction --- continued
Installation of the Glass Panels in the Doors of the Console
The glass used in the doors was ordered from a local glass supply house, but they in turn had to order a sheet of the specific type of glass that was chosen for the doors of the Console. This glass has a relative smooth front face, but the back face is very bumpy due to the presence of many small, rounded mounds of glass. It is called "Pebbled Glass" by some vendors. From the front side from a distance, it looks similar to some seeded glass materials. It is available with differently sized "pebbles."
The vendor cut the glass slightly longer than the dimensions I had specified, and by the time it arrived I had already completely finished the door frames. To shorten the panels, I hand ground them using a small metal disk with ~60 grit diamond bonded in nickel on it flat faces, keeping the surfaces cool and lubricated by frequently wiping them and the diamond disk with a sponge dipped in water. I purchased that disk at a Woodworking Show for use in touching up some carbide masonry drill bits but have yet to use it for sharpening. I have used it several times to ease the edges on other pieces of cut or chipped glass, though. Installation was straightforward once I finished removing about 1/16 inch from the glass panel, which took me about 30 minutes.
Lesson learned: Always have components such as these glass panels on hand before making the furniture components. It will save you a lot of time and frustration doing rework.
To install the glass, I simply laid the door frames down flat, inserted the glass panels, then applied a few short length "spot beads" of DAP's 50 year life Clear Acrylic Latex Caulking. Spaced around the inside edges of the frames where they meet the glass. This caulk product is milky when applied but turns clear within a day. I left the doors laying with their front faces down flat for a day, then installed them on the Console. After the caulk dried, it is almost undetectable from the outside and even the inside unless you come close and study the doors trying to determine what is holding in the glass. The caulk spot beads hold the glass very firmly; there is no rattling, yet the resilient bond allows relative expansion and contraction movement between the door frame and glass. If I ever have to or want to remove the glass panels, all I have to do is cut the spot beads with a utility knife, which can be done without touching the finish on the insides of the rabbeted oak frames.
Below is a photo of showing the "spot beads" of acrylic caulk serving as a glass panel retainer. Sorry for the poor quality of these photos!
In the first photo below, the pieces of masking tape identify the locations of the "spot beads."
In the photo below, the upper right corner of the text box is pointing to the "spot bead." They are hard to see even when viewed in person at close distance.
Building the Bookcases
The panels and associated edging strips were cut and morticed for 5mm dominos using my Domino machine as described above in regard to the Console. Before gluing on the edging strips, two rows of 1/4 inch shelf pin holes were drilled in the inside surface of each side panel, and two rows were drilled in each side of each center panel. Due to the nearly 7 ft length of these panels, I needed to "walk" the 42 1/2" inch (1080 mm) LR 32 Hole Drilling Guide Rail lengthwise along the panel to complete a continuous row of evenly spaced shelf pin holes. A significant additional design requirement of the customer (my wife) was to ensure that the uppermost level of removable shelf panels could be installed such that their elevations would exactly match that of the bottom cross piece of the TV Cabinet (yet to be built) when set to rest on top of the Console, to provide the appearance of a horizontal row of near cubical cubby holes for her to place art items.
The center vertical panel of each of the pair of bookcases is shorter than the side panels. The center panel extends vertically between top and bottom cross panels, subdividing the bookcase into two narrow columns to be fitted with short shelves. Getting the the shelf pin holes aligned at the proper elevation in all four panel faces presented an additional challenge to me, a simple bookcase comprising two upright sides with shelves extending between the sides would have been much simpler. The actual elevation of the shelf pin holes in the assembled bookcase was going to depend not only on accurately measuring and cutting the lengths of the center and side panels, but also the actual thicknesses of the top and bottom cross panels, and whether they were truly flat and straight. In hindsight, it would have been better to have first built up the base panels with sub-frames, thus making flat torsion boxes and dry fit checked and marked the desired shelf pin holes elevation on the center panel before drilling shelf pin holes in it. In practice, I added the reinforcing subframe members with pocket screws after the Console and Bookcases were otherwise fully assembled with glue.
But what I did worked out rather well. My solution was to measure and layout pencil lines extending across the panels to identify where the plywood cross panels (horizontal in the finished, installed bookcases) would intersect with the inside surfaces of the side panels, and where the shelf pin holes should be drilled. If I had had the space available, I would have laid all three panels for each one of the bookcases side by side on a table or the floor, with the center panel positioned at the correct elevation relative to the tops and bottoms of the side panels, and when in that alignment marked reference pencil lines across all of them for use in getting the shelf pin holes in the desired locations. None of the flooring in my garage is truly flat, and my driveway is steeply sloped from the street to the house and attached garage with compound crowned contours near the garage. And it was now late Fall season and the weather was seldom good for working outside. Because I did not have a large flat floor or table space available, I stacked the panels for one Bookcase on my MFTs and auxiliary table, marked their front edges and then transferred those marks to pencil lines extending fully across the faces to be morticed with the Domino and to be drilled with my OF 1400 and LR 32 with Hole Drilling Set, using a 1/4" straight bit. I did the same for the second Bookcase. I used my Woodpeckers precision carpenter's square to draw the pencil lines, always referencing from the front edges of the panels. Because the distance of the shelf pin holes from the top ends of the panels was set arbitrarily to enable adjusting the shelves to create the appearance of a stack of cubes, the Linear Stops supplied with the LR 32 Hole Drilling Set were not used - those stops are designed to place the LR 32 Guide Rail exactly either 16mm or 32mm from the pin in the Linear Stop). Instead, I substituted a Guide Rail Connector (Item #482107) and replaced one of the set screws with a 6mm machine screw to create an Adjustable Linear Stop that could be set wherever I chose. This enabled me to set the holes at whatever distance I wanted them from the end of the panels. I relied on these Adjustable Linear Stops to position the LR 32 Hole Drilling Guide Rail relative to the top edges of the panels, using the pencil lines I earlier made to confirm the locations of the holes.
Shown below is the LR 32 setup I used with my "Adjustable Linear Stop"
I did not need to use the Edge Stops from Festool's LR 32 Hole Drilling Set (Item #583290) to set the distance of the shelf pin holes relative to the front and back edges of the Bookcase panels. I eyeballed the position relative to the front and back edges of the panels. However, I while doing this, I made one mistake that later cost me some time. One of the front rows of shelf pin holes was not set back sufficiently from the front edge of the panel. At that time I was thinking that placing the shelf pins very close to the front and back edges of the upright panels would provide the widest pin spacing and thus best support for the shelves. I did not realize this oversight until after I had added the 1" thick edging on the front of the 3/4 inch plywood panels forming the short shelves which had fit well during a prior dry fit check. I used various widths of 1" stock scraps for this edging, glue it on, and trimmed the back plywood edges of the shelves to make them the needed overall depth. When I went to trial fit them again, the edging on a few of them rested on the edge of the front shelf pin instead of the bottoms of the shelf panels bearing fully on the associated shelf pins. Because of some variation in setback distance of the front rows of shelf pin holes and front to back dimension of the edging on the front edges of the short shelves, shuffling their positions solved most of the interference problems. A little relief cut or grinding of the spade headed shelf pins solved this problem for the rest of the problematic shelves.
The side panels were morticed with the Domino machine, using the same template used to mortice the side panels of the Console. Because the Bookcase panels are 12 inches wide (depth direction in the finished bookcases), only three mortices were cut in each front to back row. (The side panels and partition panels of the Console each had four domino mortices in each row). As when making the mortices in the panels of the Console, the template was referenced relative to the front edges of the Bookcase panels.
The accuracy of my method of marking the elevations of the domino mortices and template method was confirmed when I cut the mortices for the lowest level of short shelves which are secured with glue and dominos. I set the plunge depth on my Domino machine shallower than normal in the hope of not cutting all the way through the center divider panel and cut the mortices from each face of the center panel using the same template used to cut the mortices in the upper and lower full width cross panels. But the core veneer layer partially tore out and I could see that the mortices made from opposite faces using the marked lines on my template were perfectly aligned! I pushed a 5mm domino through each one to confirm that was true.
Before assembly of the Bookcases, I used my Kreg jig to drill pocket holes into the top surface of the top cross panel and into the bottom surface of the bottom panel, taking care not to place a pocket hole where a domino mortice was located. The main purpose of these pocket holes was to help draw fully together the components being glued up. Because the front and rear edging strips are offset 1/4 inch relative to the plywood panels forming the sides of the Bookcases, and the size of these cases, it is difficult twhen working alone o hold all the pieces being glued together, the long bar clamps and wooden cauls. The pocket screws, especially those placed near the center of the width of the panels helped reduce the need for cauls.
I also tried a somewhat different order for the finishing steps relative to assembly when building the Bookcases. Because I ran out of room in my shop to set all the pieces of the console to dry between finish coatings, I decided to follow the fiinish schedule only through application of the stain layer before assembly, then apply the rest of the finish coatings to the assembled cases since they would take up much less shop surfaces and spaces. And I could proceed with constuction of the TV Cabinet while waiting between coatings. And the weather had turned decidedly to Winter so I needed to do everything, including all of my spraying inside the shop, and pick up my pace if I wanted to get done before Christmas.
Assembly of the Bookcases
Due to the center standard and short shelves at at elevation 24 inches above the bottoms of the side panels and use of domino tenons, the Bookcases had to be assembled in stages. Below is a photo showing partial assembly of one of the Bookcases. Both the base cross panel and the lower short shelf panel fitted with dominos are being glued up. I shortened the dominos and inserted them first into the end of the short shelf to ensure that both short shelves would be equally secured to the center panel. Alternatively, I could have used a full lengh 5mm domino tenon and made the mortices deeper in the edges of the short shelves that were to be joined to the center panel. I chose not to do that because the next deeper incremental stop was 20mm, which would have left less of the tenon projecting into the center panel than I wanted. So instead, I left the Domino set at 15mm plunge depth and trimmed the six tenons needed for each bookcase. My shop was so cluttered at this point my bandsaw was not very accessible and my MFTs were in use for the glue up and assembly, and with my Kreg jig. So I set my Domino machine on the least depth setting and plunged a few mortices into the side of a scrap of 3/4 inch plywood, then inserted a domino tenon in each and trimmed them to uniform length on my table saw.
Note in the first photo below only the short shelf is being glued up to the side panel which is on the bottom in this photo. The other Bookcase components are in position merely to ensure that the center shelf is squared up and correctly located. I made most of the mortices slightly wider than the width of the 5mm tenons so the pieces could be adjusted if and as needed during assembly. Clamps were used to pull the components into correct position as needed.
In the photo immediately below, the top panel is being added and glued up to the sub-assembly shown in the photo just above.
Right after closing the joints with the help of a mallet and the bar clamps, I inserted the pocket screws which helped to pull the center of the side panel tight against the cross panels. Thereafter, I added the remaining short shelf and the other side panel, closed the joints with a mallet and the bar clamps, and inserted the remaining pocket screws. This part of the project was very stressful because of the number of spaced domino tenons (3 sets of 3 with nearly 7 feet between the top and bottom cross panels) to which glue had to be quickly applied, the tenons inserted, glue applied to the protruding stub tenons and all confronting surfaces.
The edging on the front of the center panel is also morticed at both ends and joined with Domino tenons to the edging on both the top cross panel and the bottom cross panel. Domino Cross Stop (Item #49348) was used to cutting the mortices in the ends of the edging strips. This accessory is quick and easy to attach to the Domino machine and also quick and easy to adjust to fit the narrow workpiece to be morticed in its end. I did not have any reason to offset any of the mortices in the ends of the edging strips, but that would also have been easy to do because the Cross Stop has easy to read and use scales molded into the moveable components that contact the sides of the workpiece to align the Domino parallel to the length of the narrow workpiece. With the Cross Stop installed and adjusted to the width of the workpiece, the workpiece is captured within three surfaces assuring good alinement for cutting the mortice in a direction parallel to the length of the workpiece, the Domino machine cannot jump laterally when plunging.
To facilitate installation of the edging on the center panel (which had to be installed by a combination of rotation and lenghtwise sliding movement because of tenons protruding at right angles on the back surface and bottom end) and slipping the tenon into the mortice in the edging of the bottom cross panel, I extended the width of the two mortices nearest the bottom of the center panel which was already joined to the bottom cross panel. Since I had not then secured the top cross panel to the center panel, I could pull on it to create enough space for insertion of the tenon joining the front edging of the top cross panel and the front edging of the center panel. Then the second short shelf was joined to the center panel. And lastly, the other side panel was glued on. Thus, mine was a slow, sequential method of assembly with many dry fit checks. Lifting and positioning the second side panel and getting all nine tenons started into their mortices and drawing them evenly home proved somewhat of the challenge. When I tapped one corner, another earlier started would pop out, and if I drove the first corner in deeper, thus canting the panel, I couldn't get the rest of the tenons to hit their mortices. But I finally got it together. These problems would not have existed if I had had a helper who could have assisted in applying glue to the many domino tenons and lifting and positioning the many mortice and tenon joints at once, and would have been less if I had done this assembly work on top of a solid table. I did it on top of a old hollow core door laid across a pair of sawhorses. That surface would bend and rebound as I struck the panel with a mallet, rather than the joints being driven closed.. A rigid support surface would have been much better. Since I had applied glue to all confronting surfaces and the tenons, and had to get the pieces to together quickly, I slid the assembly to and fro along my makeshift table so my mallet strokes would be directly above one of the sawhorses. That worked, but those were intense moments I'd rather avoid. I came very close to ruining a lot of hard work. Now I much better understand why people like Norm Abrams apply most of their trim using a continuous slot on the panel edge, biscuits for alignment and a finish or pin nailer. But I loathe using nails in furniture. The backs of each piece of this Entertainment Center are attached with small screws with an antique bronze finish in pre-drilled, countersunk pilot holes.
Lessons learned: Get someone to help when gluing up complex assemblies. Support the project being assembled on a solid surface that won't bounce when you use a mallet to drive the mortice and tenon joints fully closed. Get domino tenons that are not too tight fitment, particularly for application of trim pieces.
Dave R.
and informative. I, like other forum members, look forward to your daily "updates". And I must admit, I have learned a thing or two this past week reading about your travails. That said, may I offer a suggestion...?
