Screws and Presses

Thou shall not covet! Get real - everybody who tries their hand at bookbinding wants a real nipping press and would gladly nick the first one they could get their hands on except most people couldn't lift one let alone carry it away. Hence one of the great problems in acquiring a good old-fashioned cast nipping or standing press is their enormous weight.

But one could simply order one from a catalog and let the delivery man carry it into the bindery. Right -- I found a beautiful one in my most recent University Products catalog -- the Johnson Bronze Book Press, what a magnificent specimen. Guess how much? $3798.15 before taxes and the table to go under it is only $879.45. We'll have two, thank you.

So what is a person to do? Even if you could find one it would have to be fairly close to home or the freight would be too expensive to pay and because they are in relatively short supply, even at old flea markets or used equipment dealers, they now fetch a very high price even for models in much less than perfect condition.

Given that such a device is fairly central to the bookbinding process, I would like to offer some suggestions as to how you might affordably and easily build such a contraption for your needs. You need little more than a bit of wood, a few big hardy bolts and a press-screw.

There are many styles of book presses that one could build but there are certain technical requirements that make some structures better than others. In any case, most designs need to be total, in other words, don't pick and choose little bits and pieces from various designs unless you are confident that at the end of the day the pressing requirements will be met.

Basically a book press consists of a press-screw which moves a floating platen up and down against a fixed platen. The platen faces serve to distribute the pressure from the bottom point of contact with the press-screw. On many presses, the top platen has stronger supporting structures to strengthen the platen itself. On others, the platen is a cast iron affair which has the reinforcements cast into the design. However, a certain amount of the distribution of pressure can be obtained by using thick pressing boards of various sizes between a more simple support system. Since the pressure of a press is exerted parallel to the press-screw, the greatest strength must be in the press components which either carry the press-screw or do the squishing. The beam which carries the press-screw must be thick enough to retain its strength despite having a huge hole bored into the middle of it for the press-screw to pass through.

The first requirement is to purchase a press-screw. In order to describe actual construction, I will recommend the press-screw available in the current Lee Valley: Fine Woodworking Tools catalog. If you don't have their catalog, get one. Call 1-800-267-8767 and ask them to send you one. They are wonderful people to deal with. I am sure that there are other suppliers but I have used the press-screws from Lee Valley and can recommend them to you without reservation.

In addition to press-screws, Lee Valley can supply excellent Japanese sharpening stones, brass Chicago bolts for photo albums, various good knives, measuring tools, small spatulas, sanding equipment and much other useful stuff but not an acceptable bookbinding PVA.

I will describe the construction of two different presses using two products available on page 54 and 55 of their 1995-96 catalog. The first is a single screw nipping press and the second a double screw horizontal press.

The single press screw is item 70G01.51 called a "shoulder-vise screw." It has a 9" clamping capacity. This does not mean that your press can have only a 9" opening, only that the top platen can only move up or down 9". You can make the gap between pressing plates as wide as you wish as long as you have boards to fill the gap. If you have ever seen real or in pictures the old French standing presses with their piles of railroad track logs you will know what I mean.

The finished press is pictured here. It uses laminated 6" x 6" oak bars each 18" long (although the middle bar is cut 1/4" shorter to allow it to move freely between the side bars. The side bars are 1.5" x 6" oak and are, in this case, 24" long. The screw in the press shown in the picture is a bit longer than the Lee Valley screw identified above. But you can adjust the height to suit your needs. Decide how close together the platen plates must come. I use 1.5" laminated plywood pressing boards covered on both sides with arborite so with pressing boards on both sides of the object, the press is completely closed when the gap between the platens is just slightly smaller than 3". I use such thick pressing boards because this is one option to allow for smaller platen beams. If you used thin pressing boards, you would have to make substantially bigger platen faces under the screw.

This is certainly possible but I have very large pressing boards to 18" x 26" which fit very nicely into this press. I also have nice little 4" x 5" pressing boards of the same material. I had two 4' x 8' sheets of 3/4" plywood laminated together and then had the arborite put on and then had this large sheet cut into lots of smaller pressing boards. A local cabinet making shop did this for me and I have the best pressing boards I have ever used. Be sure to get the shiny arborite not the newer rough surface varieties. If you try your local building supply store, they will undoubtedly have a few odd sheets left over from when yellow kitchens were "in". These they will almost give away if you look desperate enough. I mean, who wants bright yellow arborite these days?

In the top beam, in the exact centre side-to-side and front-to-back, drill a hole ON A DRILL PRESS, slightly larger in diameter than the screw. If you can't do this yourself, take it to a shop where they can do it. It is very important that the hole is perpendicular to the beam itself. I must also tell you that carving a 1.25" hole in solid oak (maple is much better by the way -- I just found some water stained oak at a supplier who couldn't sell it in that unsightly condition -- except, of course, to me -- CHEAP) is a really big job and a little hand held electric drill would likely burn up before you got all the way through anyway. Trust me, have it done by somebody with the right equipment.

While you can put large screws into the press-screw plate flange, it will take 4, but screws are unlikely to hold against the pressure. Therefore the only really workable solution is to drill yet another 4 holes through the top beam. Use fairly soft 1/4" stove bolts to fasten the screw plate down. If you use hardened bolts and you really are on a spinach diet one day, you could break the screw plate with the force that you can place on it. The soft stove bolts will strip off first unless of course the screw plate is defective when cast. An even better and certainly stronger solution would be to mount the nut with the flange on the underside of the top beam. With these new press-screws it may be possible depending on the size of the reinforment of the flange on the backside. In this case, only a relatively small wod screw would be needed to hold the nut into the upper beam.

The side plates need to be fastened securely against the top and bottom beams. The best hardware to do this comes from Lee Valley on page 231 of their catalog and they are called cross-dowel connectors. Large screws will also work since the real force is shear at right angles to the joint. Therefore a much stronger join will be had by cutting in slots into both the side panels and the beam in which you place a flat brass or steel bar, 1/8" x 3/4" (the black bits in the figure). This, when firmly squeezed between the plates will make a rigid joint powerful enough to withstand enormous shear pressure. If this seems a bit complicated you can simply drill several 1/8" holes and pound in a few 4" finishing nails. These will create a shear barrier that is quite adequate. Also glue the joint with a high grade carpenter's PVA and remember that the grain of the beam should be across the beam left to right with the laminated sections one behind the other, that is, not one on top of each other. That means you will see the laminated pieces when you look down from above but not when you look straight on.

On the middle beam, (the upper platen), you screw small plates of plywood with a Bristol board under each piece to the beam front and back on both ends. This will make the slot in which the beam will travel. Then place the middle beam in the centre where it will travel and fill the end gaps with card, temporarily, so that the gap on each end is even. Then you may screw down the base plate. This does little more than carry the weight of the beam so any reasonably good size screws will do. With hard wood you will need to pre-bore the holes. You can then mount a couple of pieces of pine on the bottom to make legs and finally, I bolted these legs into my bench so the entire press is firmly in place. The handle is a piece of 1" dowel. Make it longer if you don't want to pull too hard since torque is increased the further you are from the turning centre. Lee Valley also sells these plastic self-adhesive rulers which I stuck on the top beam of the press. I have these stuck all over the workshop so I can hold a piece of paper or book up to them in almost every location. They are very useful for rough measuring of all sorts of things.

To learn about the second press...