Wireless Set No. 52 Canadian - Project

[David Dunlop]

Some initial general observations about the Kimpak padding used inside this case. It is basically a long, flat, heavy-duty, brown paper pouch that has been filled with. A mat of what is basically an 80 year old version of cellulose fibre. Think blown attic insulation today. The brown paper itself has the Kimpak logo printed in blue in diagonal rows of three along its length and was probably waterproofed with some form of oil based product because the case has that old, oily smell to it when opened in spite of no trace of oil ever being spilled in it, and it never being designed to hold oily items. I also know that the prior owner of this case obtained it as a newly surplussed item back in the 1970’s and used it as intended, to store NOS radio valves in their factory boxes.

The pouch of the padding is formed by folding the paper and creating a longitudinal running seam down the middle of the back of the pad, sealing in the cellulose in the process. The finished width of the pad is 8 inches and it was probably supplied by Kimberley Clark to Canadian Marconi Company in rolls, cut to required sizes at one or more stations on the production line. All of the padding was installed after the cases were painted and probably just before the exterior stencils were applied to the front of the case. The lengths of the pieces of padding all seem to be cut just long enough to form a snug fit for the two cut ends up against the interior wood surfaces of the case. Perhaps to keep these cut ends from lifting and tearing. Some edges look like they may have been tucked down in place.

The two pads in the lid and the floor of the left side compartment could have been installed at any point in the padding installation process. However, in the main, right side compartment, there was a specific sequence for the installation. The Kimpak is only 8 inches wide. The depth of this compartment is 9-1/2 inches, so the padding around the sides is set 3/4-inch off the bottom of the case all the way around, and there is a corresponding 3/4-inch space above the side padding. My first thought was that a slightly undersized 3/4-inch thick board would just be dropped into the box and then the side padding stapled in place. But then you would never get the board out. So they must have used two small strips of 3/4-inch board, two or three inches wide, placed one at either end. The padding is stiff enough this would work. After stapling the side padding in place, the two space strips could easily be slid parallel to the long axis of the case and lifted out. The bottom pad would then be stapled in place.

The one piece side pad starts butted into in the left rear corner of the main compartment, against the partition panel. It then runs across the rear wall of the compartment and wraps around the right rear corner. As it wraps to the right side wall, there is a vertical fold facing to the rear wall to help make the padding fit snugly into the corner. The padding runs along the right side and wraps into this corner, again with a fold on the right side wall, pointing to the rear. The padding then runs along the front wall of the case and wraps around the left front corner snugly, and with no fold this time, and heads along the partition wall to butt up against the Kimpak on the back wall.

The bottom pad in the left compartment has only one staple in each corner to secure it in place.

The padding in the lid has 3 staples down each end, one half to one inch in from each end, and two more front and back, roughly equally spaced.

The bottom pad in the main right side compartment has three staples down each end and one in the middle, front and back.

The side pad has four staples top and bottom on each end, 1/4 to 1/2 inch from the edges. There are five staples top and bottom roughly evenly spaced, 1/4 to 1/2 inches from the edges.

The first two photos posted today show the 3/4-inch gap at the bottom of the side padding in the main compartment. The third photo show the cut ends fitting against the case panels. The fourth photo is the start point of the side padding in the left rear corner of the main compartment and the last photo is one of the rolled in corner with the vertical fold just visible.



David