In this design I considered a variety of issues for woodworkers of all levels to consider. Some considerations surround the joinery while others consider the use of tools. In any product design using solid wood, and this project uses only solid wood, the designer must consider such things as shrinkage, swelling of wood fibres, things like these. To answer my questions requires a broad base of basic understanding of hand tools and their applications, joints and their functionality. No need to kick this can down the road so let’s see where we end up!
My answers are lower on the page. Scroll down when you are ready to see them. Get your pencil and paper and see how well you do.
Question 1: The main body of the project has three common names furniture makers often refer to to describe the superstructure. Can you name two of them?
Question 2: The sides, top and bottom have the grain oriented all in the same direction. Why did I choose to orient the grain this way and not horizontally for the sides?
Question 3: Why did I use such a narrow stepped housing dado, 1/4″ (6mm) instead of a full width one the thickness of the whole side piece of 3/4″ (20mm)
Question 4: The back panel is different to the sides in that it is grooved into the top, bottom and side pieces. Is there an advantage to this?
Question 5: Is there a reason not to use screws alongside the housing dado, to ensure the joint remains together?
Question 6: Why did you use roundovers to the four edges of the top and bottom pieces?
Question 7: The guide supports for the drawer to run on rely only on screws. Wouldn’t it be better with some kind of housing dado or other joint for this?
Question 8: The drawers themselves have the grain running in the opposite direction to the box. Does this not then compromise the project because if the carcass shrinks the drawers will protrude past the front. If it expands, the drawer fronts will sit below the surface surrounding the drawer?
Question 9: I don’t see any end to the housing dadoes front or back. What if the sides shrink or expand more than the top and bottom? Will there be a gap?
Answer 1: Carcase, case or cabinet.
Answer 2: So that expansion and/or contraction (shrinkage) would all take place in the same direction (across the grain) and so without conflict that leads to stress and cracking. Grain does not shrink or expand noticeably in its length but across its width the expansion and contraction can be expansive and increases the wider the boards.
Answer 3: I wanted to minimise any distance of shrinkage. The narrower the housing dado the narrower the interconnecting ‘tenon’ part and so the minimal amount of shrinkage will take place. I also wanted to distance the rim of the housing dado from the outer corner edge of the top and bottom pieces to increase the length of continuous grain the outer area relies on which then increases the intrinsic strength of the surrounding outer support wood. Also, the step over the outer line of the housing dado is hidden inside the step so that no gap can ever be seen at this juncture.
Answer 4: The advantage is that we have created a carcass that holds what we usually call a floating panel. The panel is not fixed or glued in anyway but it is housed in on all four edges of the panel. This allows the panel to expand or contract according to the atmospheric moisture content (AMC) which minimises the risk of splitting. The grooves also constrain the panel and so prevents the panel from future warping.
Answer 5: You can use screws if you wish to however it will prove unnecessary as the glue surfaces to the joint span 1 1/4″ and this should prove sufficient. Screws usually need hiding with plugs of some kind which is just another added step too.
Answer 6: For two main reasons: The first reason is to remove the hard corners which tend to fracture when knocked. I could have simply planed a 45-degree corner off but the project would still look too heavy and clunky so my second reason for the roundover is to lighten the finished appearance of the project. Of course I could have used thinner wood but I felt I needed the bulk to ensure and solid joinery construction with built-in longevity. Because I envisage moving the piece around my workshop according to convenience, it is easier to handle with the rounded edges.
Answer 7: We chose not to glue these supports so that the sides can still expand and contract. Two or three screw securing the supports is more than adequate and the allow the sides to expand and contract.
Answer 8: I made the drawer half an inch shorter than the sides of the case and installed stops distanced from the front edge of the case the thickness of the drawer fronts. This enables me to align the drawer front with the surrounding superstructure and set the distance I want for the two drawer stops from the front of the drawer line to the back of the drawer front. This means that the drawer front always aligns perfectly.
Answer 9: The housing dado stops 3/4″ from both front and back edges of the sides so the corners are stepped to the same depth as the housing dado. This then hides any possibility of a gap occurring at any stage.