Wednesday, July 13, 2011

Knife hinges...(cont'd)

Most recently, I've been working at creating the mortises for the doors. Accurate measurements are critical for this fitting and I typically measure and re-measure before even beginning to chisel out the knife hinge mortises. I dry fit the cabinet sides, top and bottom and then use a spacer I created as part of the fitting process to transfer the hinge mounting offset to the top and bottom panel. This is the offset from the side panels to the hinge in the door. As well, I transfer the length of the hinge in the door panels to the top and bottom.

Once I have this particular measurement marked out on the cabinet top and bottom for both doors I can use the hinge itself to mark the opposite, parallel side of the mortise. A short time later and the mortises are completed in the top and bottom panels. The next critical test is dry fitting the door panels and knife hinges into the cabinet. This part is successful. I have left a little extra in each door panel where they meet in the center to allow me to fit them so the rabbeted ledges will meet correctly.

I'm also very happy with the choice of graphics in the ambrosia maple veneers I have chosen. I need to perform some final fitting of the mortises, very small adjustments in the hinge placement withing the mortise itself. I had purposely left the length of the cabinet mortises a fraction of an inch short so I can dial in the placement of the doors. The very small reveal at the top and bottom of the doors needs to be perfectly parallel with the respective cabinet top and bottom panels. Once I have this done I will begin the cabinet glue up process.

Sunday, July 10, 2011

Knife hinges...

After the doors are fitted into the cabinet opening the next step is to layout and create the hinge mortises for the knife hinge pairs. Each door has one pair of knife hinges as they come in pairs. I use spacers and my small adjustable square to make certain the doors are spaced uniformly from the cabinet case. This is important as the door reveal all around needs to be uniform. After the hinges mortises are marked the process of creating the recesses is accomplished with a set of sharp chisels and a small mallet.

Once the hinges mortises have been created on the doors, the hinge markings are transferred from the doors to the cabinet to maintain accuracy.I do this with the use of a spacer. The spacer allows me to maintain the same reveal of the door from the cabinet sides. Creating the hinge mortises with hand tools is somewhat of a pleasant task although it can take a while. Care needs to be exercised with grain orientation as the grain is reversed depending on which corner of the cabinet is being mortised. I use both chisel bevel down and back down orientation to remove waste from the hinge.

The outline of the hinge and its offset from the edge of the cabinet and doors is fairly important, I usually mark this with a sharp knife, then with a wide chisel define the mortise using these fine knife markings. Once this is accomplished, removing material from the recess is fairly foolproof. I remove wood from the hinge recess in stages, exercising care not to go too deep in one pass of the chisel. To the left, a photo of the completed knife hinge mortise on a door, one of four to be completed.