Paper Mold and Deckle

Mold Redux; or, the difference between prototyping and screwing up

Having finished the white oak mold and deckle, I'm rethinking my choice of woods. Sure, white oak looks great and it's really stout, but it weighs significantly more than the mahogany in the Timothy Moore model.

Paper mold with mesh sewn on partway:

White oak mold and deckle, from corner


I'm really happy about how the deckle came out. The joint was tricky, but quite strong despite the short grain on the nub that sticks out on one end:

!
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I realized an interesting difference in this construction, compared to most frame joinery. Most frames are joined so the two sides press on in parallel from opposite directions. For example, in a dovetailed drawer, the pins are on the front, and the two sides with tails press on the pins from left and right in opposing directions. In the joinery for the deckle, the sliding dovetail joints chase around the four corners of the frame. So the bottom right corner has the dovetail pointing right, the top right corner points up, the top left points left, and the bottom left points down.


This makes the frame harder to put together, but also less likely to fall apart.

But back to the weight: if I had to lift this out of as vat of paper pulp 500 times a day, I'd be pretty sore. So I'm thinking of redoing it all in mahogany.

More on the deckle joint

To understand the deckle joint, I drew it first in Sketchup. Here's how it looks, apart and assembled:











After assembly, I used a rounderover bit to take an arc out of the outside corners.

mileskimball said:

More on the deckle joint

To understand the deckle joint, I drew it first in Sketchup. Here's how it looks, apart and assembled:

After assembly, I used a rounderover bit to take an arc out of the outside corners.

Click to expand...

Hi, Jan -

If you want a traditional laid paper mold, with chain lines, you may choose (as I did) to make the mesh yourself. I wasn't able to find anyone who would do it for less than $2000 (!).

If you could send me an email address, I can share with you some photos and a short framentary video of the loom I made. It's a tedious process - kind of like weaving by hand or knitting.

Essentially, you need two kinds of wire: phosphor bronze and steel fishing wire. Phosphor bronze is hard to source, but I was able to find some eventually. Steel fishing wire is used for trotlines to fish for big fish like sturgeon. I can't recall the thickness of either, unfortunately.

You cut the PB wire into suitable lengths, but then if it came in a loop of wire, you'll need to straighten them as much as possible. I actually made a wire straightening jig, which used offset pulleys to bend the wire against its bend from the loop, gradually straightening it. I had no luck with a common technique, which is essentially to yank and stretch the wire straight. It just broke. If I had it to do over again, I'd pay a little more to have the wire straightened for me. Typically a steel or metal supplier will have the equipment to straighten the wire and cut it into suitable lengths.

Then you set up a frame with screws in a row at the top - about 3 cm apart - to locate the chainlines. You take some fishing wire - about 7x longer than the desired depth of the screen - fold it in half, then wrap each end onto a spool, so you have two spools holding half of each piece of wire. At the middle point, you wrap the wire around one of the screws and use the spools to twist the wire around itself 3-5 times. Continue along until you have one wire and two spools for each screw. Lay one spool from each screw away from you, and the other toward you. Lay a piece of the PB wire in the weft between the two ends of all the wires, then one wire at a time, pull to spool that's away from you toward you, and the spool that's toward you away from you. Cinch the twist, but not too tightly - you don't want to break the wire. Once you've twisted all of the fishing wires around the first PB wire, go back and make sure everything is snug. Then lay in another PB wire and repeat.

Hope this helps -

Miles

mileskimball said:

More on the deckle joint

To understand the deckle joint, I drew it first in Sketchup. Here's how it looks, apart and assembled:

After assembly, I used a rounderover bit to take an arc out of the outside corners.

Click to expand...

A few afterthoughts:

You might notice that on the loom I've drawn some lines down from each screw. These gave me a sight line to make sure the chain lines stay relatively straight. It's easy to let them go off course. I found that a cheap plastic hair comb made a good tool for nudging the chain wires straight, which I'd do every few lines.

As you twist the chain wire around the laid PB wires (pulling one spool toward you and the other away), be sure to twist them always in the same direction (clockwise or counterclockwise) for consistency.

The PB wires tended to sag in the middle of the loom, so I inserted a small block of wood loosely to support them.

To wrap the spools with wire:
1. Drill a small transverse hole - 1mm - in each spool.
2. Drill a larger hole in the end of each spool, sized to friction-fit a short piece of ~6mm dowel.
3. Chuck one end of the dowel in a drill, and press a spool onto the other end.
4. Poke a wire-end through the small transverse hole.
5. Hold the wire in light tension, then use the drill to spool the wire. Go slowly!
6. When you approach the screw anchoring your fishing line, stop and wrap the spool with a rubber band to hold the wire in place. This also allows you to feed out more wire as you need it in the weaving process.

mileskimball said:

More on the deckle joint

To understand the deckle joint, I drew it first in Sketchup. Here's how it looks, apart and assembled:

After assembly, I used a rounderover bit to take an arc out of the outside corners.

Click to expand...

Hi Mileskimball

Thank You for your exhausting answer and sharing your know how with us. Let me say I admire your patience. I guess this is the only way you can do these things these days. There used to be people with professional looms however all these crafts are now more or less gone.
I found this interesting dvd: http://iarecordings.org/productions/p20.html
I'll keep you posted it if I decide to go and make the mesh myself using your way

Here is our private email: [email protected] or you can see few pictures from our workshop here:
https://www.facebook.com/Petrus-Papier-Exkurzie-do-papierne-a-ru%C4%8Dne-vyr%C3%A1ban%C3%BD-papier-219406638144380/

Once again Thank You
Jan