A Stanley knife and a square need to be used to create a knife line along the shoulder line following the markings on the edge of the material that needs to be removed. This will guarantee that when the chiselling to finish the joint when the material is removed is done, there will be an accurate, clean-cut edge. Then, the wood needs to be secured into a vice to hold it still, using off cuts of MDF to protects its finish where necessary. Now, a dovetail saw is to be used to saw down the vertical marked lines of the comb joints. This task should be carried out carefully, making sure that the saw is kept straight on both sides of the wood. When these initial cuts have been made, the wood can be turned to remove the material at the sides which is to be removed.
However, if any material is enclosed on both sides by wood that needs to be left, a coping saw should be used to make a cut down the diagonal of the material that is being taken out. This results in there being a small amount of material that is still to be removed. Now a chisel and a mallet need to be used to remove this material and leave a smoother finish. The material is clamped to a table using a g-clamp and MDF to protect the wood from damage. Now, the chisel is held on the wood, a small distance from the shoulder line and used to remove as much of the wood as possible, when there is only a small amount left, the wood must be on the table with the face that is to be used on the outside of the unit facing upwards. This is to ensure that when the frame is put together, the joints that will be seen will be off the highest quality. Now the chisel is put into the knife line previously made and held vertically and struck to remove all the material. This process needs to be repeated for all of the comb joints that have been marked out. These two completed pieces of wood are now used as a template to mark out the other two pieces. The cut piece is rested upon the wood to which it will be joined and the area where the material has been removed from is drawn around, not with a pencil, but a Stanley knife for more accuracy. Using this method, the joints are more accurate in general because any mistakes in the cut of the first joints will be rectified here. Obviously, opposing pieces of wood will now be removed and the process described above repeated. Now the joint is complete and should interlock. These will be secured with PVA glue.
Before the frame is glued into place, a rebate needs to be cut into the bottom of
the mahogany for the MDF base to be glued into. The base does not need to support a great deal of weight so the cut that is made into the mahogany frame does not need to be very wide. Markings will need to be made on the wood to indicate the boundaries of where the material is to be removed. These markings are to be made with a marking gauge, this will serve to not only indicate the material which is to be removed but also provide a knife line which will give a cleaner cut when machining. The use of a marking gauge will ensure that when the base, which will have right-angled corners is fitted, it will not leave any gaps. The rebate will be carried out using the milling machine. Off cuts of MDF can be used in conjunction with the existing clamp on the machine to secure the mahogany so that the cut made will be perfectly straight. In industry, this task would obviously be carried out in a faster, more efficient way; it is likely that a computer-controlled router would be used. This part of the manufacture should not take a long time; it should be possible to complete it in around an hour.
The mahogany frame would then be glued together in order for the MDF base to be glued into the rebate that was just created. Providing the comb joints have been created with the degree of accuracy required the pieces of wood should simply slot together with neither excess resistance nor gaps from the woods. The PVA should be put onto all the three surfaces of the joint that will be in contact with the other piece of wood. This frame will then be held together using sash clamps, with off cuts of MDF to protect the surface from damage from the clamps. The frame would need to be clamped in all directions, ensuring that each joint is tight. Then, when the frame is clamped, a tape measure can be used to measure the diagonals of it to make sure that it is a square, if it is not, clamps should be adjusted until it is.
When the glue has dried, the comb joints must then be finished. There should be excess material on the joints. Most of this should be removed with a hacksaw leaving a small amount overhanging the edge of the frame. In order to make the joint flush with the rest of the side and leave a good finish, a plane must then be used. Planing must always be done working into the wood, not off the edge, as doing so will increase the risk of chipping material off of the side. When the plane has been used and the comb joints are level, a power sander can then be used over the whole of the edge to ensure that all of the material is level, removing any imperfections the plane may have left and leaving a good surface finish.
Green felt then needs to be attached to the inside of the base of the product. The felt should have a self-adhesive backing, so the it should simply be laid into place to glue.
