|Article by Sue Comont, based on lecture notes from Rushhden Boot and Shoe School, 1935 - 1936 and 1948 - 1950|
Shoemaking - Finishing
Finishing serves two purposes. It makes the shoe attractive and adds character, and makes the edges more water resistant by filling the fibres of the edges with wax before sealing them. There are a number of processes involved:
1 Decoration of the welt
Another method of dealing with stitched welts is indenting. The tool used is a cone shaped wheel which is deeply serrated with a number of indentations to the inch, giving a stitch separator effect.
2 Heel trimming and Breasting
Trimming is done on an Ultima Machine. This has two spaced cutters revolving at 2,000 RPM. T
hese knives give a chopping action which blends the heels together as it removes the surplus leather from the heel.
Heel breasting involves the removal of surplus material from the front of the heel. For heavy work a straight knife is used.
3 Edge Trimming
The cutter, which has 16 blades, running at 10,000 RPM, planes surplus leather off the edge, giving a square edge to the contour of the lasted uppers. The shoes should be trimmed in pairs.
An x-ray wheel is used to enable the operator to strain the abrasive tightly. The wheel has a felt on which paper can be put for a cushioning effect. Heel scouring is getting the heel into shape on this machine
When the soles are being prepared for colouring, the object is to remove the grain, but care must be taken not to take off too much or the middle layer of coarse, loose fibres will be reached and the result would be patchy bottoms and weeks of wear taken off the shoe. Bottom scouring will either make or mar the shoes.
Special attention should be paid to the drying of the bottoms before scouring as this will save on the emery paper and also, if not properly dry, the bottoms will lose their lustre in a very short time, becoming dull and needing finishing for a second time.
Applying heat just before the bottoms are scoured accomplishes several things. It carries off the moisture which has soaked into the grain of the sole and stiffens and tightens the fibres. If the fibres are damp, they are limp and flexible so the abrasive, instead of cutting through them, merely causes them to lie down. When this happens, the downy nap which is so essential to the reception of bottom stains, is not created and a fine bottom cannot be expected. Heat will cause the fibres of the grain to stand up to the abrasive and to be cut off cleanly so when the bottom leaves the scourer it is clean and white.
If moisture is present, the bottoms appear mottled and discoloured. Even painted bottoms require the sole underneath to be of uniform colour. The heat must be controlled though so the soles are neither baked nor burned.
The scouring machine has two rolls of emery paper, one coarse and one fine.
The coarse one is used first to remove the natural dirt and the necessary amount of grain. The coarse paper may be of any desired grade of grit according to the quality of the sole leather and shoe.
The fine paper is used for removing the scratches made by the coarse grit and also to raise the nap which is necessary for good bottoms.
5 Colouring and Polishing
These are used for covering bad soles or anything else that looks bad. It is also used when colour is needed. The colour should be matched to the upper. China clay is used for cover, dye gives the colour and oil is used to give a good flow. Casein gives evenness in flow and a good finish. A paint completely covers the bottom so the grain of the leather cannot be seen. The colour of the bottom is that of the paint used. Paint should be capable of covering anything in the way of poor stock as well as achieving colour in such a way that the fact of concealment is not noticeable to the casual observer. For this the paint must not be too thick or muddy. All stains and paints must be well stirred.
Gum stains are applied with a soft silky sponge and rubbed off with a power brush. The operation must be done quickly.
These consist of colouring matter containing a certain amount of bleach which will lighten a dark or stained sole, while at the same time, the sediment will cover the stain which the bleach cannot remove.
6 Colouring and Burnishing of Heels
A film of wax is put onto the heel and evened out with a pad to look hard and solid.
Colour must be put on evenly with a camel haired brush. No colour should be allowed to get on the uppers or bottoms. Whenever possible, colour should blend with the uppers. Two kinds of machine are used to set edges the Auto and the Regal. When using the Auto, the substance and the shape of the edge dictates the choice of iron. The shoe is jacked in the machine and the iron is placed on the edge. The edge is set in motion and the shoe traverses twice round the oscillating iron which works the wax into the fibres. On the last traverse the iron remains still and sleeks round. The same shape iron must be used as the cutter used to trim the edge.
The waists are set on the Regal attachment.
After setting, the wax will have been ironed into the fibres and sealed, leaving a moulded edge.
Three methods of polishing are used: