Straightening Paper Mould Laid Wires

Wire can be purchased in coils or on spools. In either case the wire comes off curved. In order to make a laid paper mould facing or backing it is necessary to make it much straighter.

Above, a piece of .0226″ diameter 1/2 hard phosphor bronze wire right off the spool resting on some of the same wire that has been run through a straightener and cut into lengths. While not perfectly straight, the processed wires can be made into a laid facing.

The major curve of the wire is called ‘cast’. This corresponds roughly to the diameter of the spool or coil. Another way that the wire is curved is called ‘helix’. The helix can vary, from very slight as shown above, or very ‘steep’ as shown below.

The same two pieces laying flat. The smaller circle of wire is the 1/2 hard wire mentioned above, while the larger circle is ‘full hard’ or ‘spring tempered’ wire of the same diameter. This wire has a more pronounced helix shape and won’t lay as flat.

A traditional way to straighten wire. The wire straightening blocks above and below are from Ron Macdonald’s collection of tools. These photos were given to me by Serge Pirard who studied with Ron and now makes moulds using many of Ron’s tools.

I tried to straighten wire this way but soon gave up!

Above and below are photos sent to me by Sergey Nasaev of Russia.

This is the wire straightener that I made using the information sent to me by Sergey. Ball bearings are stacked in pairs to create grooves which guide the wire back and forth to remove the cast. I expected that the wires should come out almost perfectly straight, like the pre-straightened wire I had been using for years. So, I was a little frustrated at first when the wires weren’t as straight. In retrospect this turns out not to be necessary or even desirable. If you try to make perfectly straight wires this way you may go crazy!

I made a second straightener out of steel with bronze rollers. The base plates of the first design were made of plastic. Steel, being much harder, can be more accurately calibrated. Now I can record the best settings for various sizes of wire so this unit can be used for all sizes of paper mould laid wire. Wire straighteners can be purchased but I chose to try to improve on what I had instead. (Besides, I like to make things and this looked like a fun challenge.)

A closer view of the steel and bronze wire straightener. The first set of seven rollers is used to remove the cast. The second set is used to remove any remaining curve caused by the helix.

The horizontal bank viewed from above. You can see that the rollers are set to bend the wire back and forth and less aggressively as the wire moves from left to right. Adjusting screws are located at either end of the slot between the rollers and are accessed through deep holes in the front plate. The two tightening screws are visible at the bottom of the photo.

The vertical bank. I have the best luck using five rollers here. Wire this light requires only 7 or 5 rollers per bank; heavier or harder wire needs more rollers.

The wire enters the horizontal bank of rollers. The cast is removed and slightly reversed by the first three rollers. Each trio of rollers creates a bending action as the wire is forced around the middle one. The remaining rollers form overlapping groups of three that apply a gradually diminishing amount of force. The wire is forced first one way, and then the other, to gradually change its shape from very curved to nearly straight.

After the first set of rollers are adjusted the wire will look fairly straight when viewed from directly above. But it may still have a noticeable curve when viewed form the side. This curve is a result of the helix and the second set of rollers have the job of removing it. Since this is much slighter they don’t have to push as hard. The wire lengths seldom turn out completely straight. If the straightener is calibrated right the wires repeatedly cycle from nearly straight to less straight and then back again; but fortunately staying within a useful range. I don’t fully understand all that is happening but think the wire has acquired some slight variation in the spooling or coiling process. Also wire twists slightly as it is unspooled. Either may cause the wire to shift slightly in the rollers, affecting the final shape. (This is my current theory.)

I pull the wire with this pair of wire cutters.

One jaw rides along the fence to keep the pulling angle constant.

When the outside handle hits the back stop the handles are squeezed to nip off a length of straightened wire. Then the cutter is moved back to the front stop to grab another length to begin again.

The top three bundles are .0226″ diameter 1/2 hard wire and will be made into laid facings for three moulds, two 12″ x 18″ moulds and one 10-1/2″ x 15-3/4″. The lower three bundles are .0254″ diameter wire and will be used to make the backing wires for these moulds. They are all to be “double-faced laid” (also known as “modern laid”) moulds.

Wire straightening is fairly new to me. I made moulds for about 25 years using wire that I purchased pre-straightened in lengths. After seeing a video of Ron Macdonald pulling wires from a coil I was inspired to try again. I like the idea of not needing a source of pre-straightened wire. I think that the hand pulled wires give a more interesting surface which carries over to the paper made on the mould (though this is pretty subtle).

I have tried to convey this information clearly. If something doesn’t make sense or if you would like further clarification let me know. I often have extra photos that can be posted and can also try to state things more clearly if I am aware of your questions.

2 thoughts on “Straightening Paper Mould Laid Wires

  1. How does straightening relate to drawing? Or, to put it another way were historical cover wires made directly from die drawn stock?

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    1. It is very possible that in the past wire was drawn through dies in the same workshop in which moulds were made. In that case it would make perfect sense to cut wires to length right from the freshly drawn wire. They would be nice and straight. It is my understanding that when wire is drawn through a die to a certain diameter it has to enter the die annealed (softened) in a very slightly larger diameter. The wire is in the same operation reduced in size, straightened and hardened. But if the wire must be stored or shipped it is not practical to keep the wire straight unless it is known what length the wire needs to be. Otherwise the wire would need to be spooled or coiled for convenience. Either would put a curve in the wire. This is my understanding and may not be totally complete. If I remember right, Nathan Sellers of Philadelphia, the first American Mould Maker ran a wire business in which wire was drawn as well as woven into screen and made into other products as well. I suppose he might have made his laid facings from freshly drawn wire. I think he also invented a mould maker’s loom.

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