One of the bench details Roubo mentions in passing is a grease box, mounted under the benchtop. The engraving at Plate 11 shows a simple box, but on the whole there is not much time spent describing the grease box. Hand tool work benefits greatly from a lubricant for plane soles and saw plates, and regular readers will know that I use mutton tallow as my lubricant of choice. Adding the grease box mentioned by Roubo was high up my priority list when I started planning this build, and it turned out to be a very enjoyable, and quick, addition to the bench.
Roubo does not give any dimensions or specific details for the grease box. I decided to use an offcut from the stretchers, which I trimmed to length so that it measured 5 pouce long, three pouce wide, and 2 pouce thick. While this is a simple part of the build, the sequence of operations is critical if you are to enjoy easy workholding – carry out key operations in the wrong sequence and life will be that much more difficult. After laying out the grease compartment and the shape of the box, I drilled the mounting hole, as it was easier to hold the workpiece with a holdfast before the box was hollowed out and shaped. Another reason for this order was that I could then test the layout of the compartment by holding the grease box in place under the bench top with an auger bit through the mounting hole, and pivot the box out. Once I was happy with the layout and the position under the bench, I clamped the box to the underside of the bench next to the left-hand front leg, and drilled the pilot hole for the screw in the benchtop using the mounting hole in the greasebox as a guide.
To hollow the box I used a forstner bit in my North Bros brace, as this removed material rapidly and the centre point leaves a much shallower divot than the lead screw of an auger bit. The walls of the box are 1/4 pouce thick, and I left a 1/2 pouce thick bottom. Counting the revolutions of the brace resulted in a pretty even box floor, following which I pared the walls flat and square with a wide chisel.
Most of the work on the grease box was shaping it. I decided to make my grease box roughly the same shape as that shown by Roubo in Plate 11, with a rounded end, and a gentle cutaway under the mounting screw. After gently rounding the front corners of the box with an Auriou 13 grain rasp, I then shaped the rounded rear end with a 9 grain rasp (also by Auriou). The 9 grain rasp is aggressive but still very precise, and by working from each side to the apex of the curve, I was able to achieve a flowing curve quite quickly. The tool marks were removed with the 13 grain rasp and a quick rub down with sandpaper (the first time I’ve used sandpaper on the bench build).
Shaping the cutaway involves working across the full width of the box. Instead of working across the full width straight away, I prefer to bevel one edge and rough in the curve on that edge before expanding the curve across the width of the box, refining as I get closer to the line. The 9 grain rasp roughed in the curve, and then I removed much of the waste using a wide firmer gouge to work across the grain. Once the curve was roughed in, I went back to the 9 grain rasp. Each Auriou rasp is hand-stitched for either right or left handed use, and is intended to be skewed across the workpiece (I visited the Aurio forge in 2016 – see posts here and here for more about these heirloom tools). However, ecause of the width of the box, I worked side to side, moving the rasp across the box instead of skewing it. This ensured that the curve was even across the width, and still removed material cleanly. Once the curve was shaped, I moved to the 13 grain rasp to remove tool marks, followed by sandpaper.
Once I was happy with the appearance of the box I gave it a coat of boiled linseed oil, and left it for 24 hours for the oil to dry, before mounting it under the bench using a 1/2″ x 2″ square headed lag screw and washer from blacksmithbolt.com – this will easily support the weight of the box. The mounting hole in the box is slightly larger than the width of the bolt, meaning that it pivots freely, and I also drilled a flat area to allow the bolt head and washer to seat cleanly on the cutaway. All I need to do now is order some more tallow (or possibly paraffin wax) and load it up.