Building a Bookbinding Press From Scrap Hardwood

The first book Junie bound in our shared garage dried under a stack of three cookbooks and a cast iron skillet. It came out with a cover that rocked on the bench like a cupped floorboard and a spine that had pulled the endpapers into small wrinkles. She asked whether I had any scrap wood that could do better. I had a pile of maple and oak offcuts from a table job, and that evening became the press I am describing here.

A bookbinding press is not a fancy tool. It is two flat boards and a way to squeeze them together evenly while glue dries. The reason people buy a cast iron nipping press for a few hundred dollars, or give up and use cookbooks, is that the homemade versions often fail in one specific way: the boards bow under pressure and squeeze the edges harder than the middle. Most of this article is about avoiding that, because it is the part most build guides wave past.

Why a stack of heavy books is not enough

Weight on top of a book spreads over the whole cover, and the pressure it creates is small. A ten pound dictionary on a 6 by 9 inch text block works out to less than a fifth of a pound per square inch. Wet PVA and wheat paste pull paper as they shrink, and that weak, uneven load does not hold everything flat while the moisture leaves. The stack also tends to sit off center, so one corner gets most of the weight.

Two bolts and a pair of wing nuts can put far more force on the same block, and you can feel it tighten. The catch is that the force enters at the two ends, not over the whole surface. A thin board between two bolts behaves like a shelf with a heavy load: it sags in the middle, except here the sag runs upward and away from the book. That is why the wood choice matters more than the hardware.

Choosing the scrap

You want hard, stable, flat stock at least one inch thick after planing. Hard maple, white oak, beech and ash all work. I used a piece of maple that came out at 1 1/16 inch and a bottom board of white oak at 1 1/8. Softwood such as pine dents where the bolt washers bear down and flexes more for the same thickness, so I would only use it doubled up and glued into a thicker panel.

Look at the end grain before you commit. Quartersawn boards, where the growth rings run roughly up and down through the thickness, stay flat through seasonal moisture swings far better than flatsawn ones with arched rings. If you have never sorted offcuts this way, the notes on reading wood grain before cutting cover what to look for. Long grain should run from bolt to bolt, because a board is stiffest along its length.

Avoid MDF for this. It is flat on day one, but it sags under sustained load and swells near its edges the first time damp paste touches it. Good Baltic birch plywood at 3/4 inch can do the job if you laminate two layers, though I like solid wood because it can be planed true again when it eventually moves.

Cutting list and hardware

For a press that takes books up to about 7 by 10 inches, I cut both boards to 14 by 10 inches. The hardware cost me $13.40 at the hardware store down the road:

• Two 3/8-16 carriage bolts, 6 inches long
• Two fender washers with a 3/8 inch hole
• Two wing nuts, or star knobs if you want easier grip
• A scrap of waxed paper, which you will replace often

Six inch bolts leave roughly 3 3/4 inches of opening once the boards are stacked, which is plenty for a stack of two or three thin books between pressing boards. If you bind thick journals, buy 8 inch bolts.

Building it in one evening

The whole job took me about two and a half hours with a jointer, a planer and a drill press. With hand tools, budget a full Saturday morning, mostly for flattening.

1. Flatten one face of each board and check it with a straightedge in three directions: lengthwise, across, and corner to corner. A gap you can slide a sheet of printer paper into is too much.
2. Clamp the two boards together with the flat faces touching and mark hole centers 1 inch in from each short end, centered across the width. Drilling both boards together keeps the holes lined up.
3. Drill 3/8 inch holes through both boards with a drill press or a guide block, so the bolts run square to the faces. A hole drilled at an angle makes the top board twist when you tighten it.
4. Counterbore the underside of the bottom board about 1/4 inch deep with a 7/8 inch Forstner bit, so the carriage bolt heads sit below the surface and the press sits flat on the bench.
5. Square the holes in the bottom board slightly with a file so the square neck of each carriage bolt locks and does not spin while you tighten the nut.
6. Ease every edge with a block plane or 150 grit paper. Sharp corners will bruise book covers.
7. Finish the inner faces with two coats of shellac and a coat of paste wax. Glue squeeze out wipes off wax far easier than bare wood.

Fixing the bow before it shows up in your books

Even a thick board flexes a little when tightened at the ends. My test is simple: put a single sheet of paper in the middle of the press, tighten the nuts firmly, and try to pull it out. If it slides out easily while a sheet near the bolts is locked, the boards are bowing.

The fix is a slight crown. I planed the inside face of the top board so it is about 1/32 inch thinner near the ends than in the middle, a few passes with a smoothing plane at each end. When the bolts pull the ends down, the crown flattens out and the pressure evens across the book. Woodworkers use the same trick on clamping cauls for glue ups. It took me three rounds of test and plane to get the paper test to grip evenly, which I mention because the first attempt will not be perfect either.

The other habit that helps is pressing boards. Put the book between two smaller boards of 1/4 inch acrylic or melamine faced board, cut a little larger than the book. They spread the load and keep any finish from the press away from your covers.

Using it without crushing anything

Tighten the two nuts in turns, a half turn each, so the top board comes down level. Stop when it feels firm, not when your wrist hurts. Over tightening squeezes glue out of the spine and can dent soft book cloth. Put waxed paper between any glued surface and the next sheet, and leave the book in overnight. Junie's rule, which I now follow too, is at least twelve hours for cased books and a full day when the weather is humid.

Her notes on patience with bookbinding glue explain why rushing the time in the press undoes most of the work. My only addition is that the press makes waiting easier, because you can stop checking. Once it is tight, walk away.

A job for this week

Go through your offcut pile and pull two pieces of hardwood at least 14 inches long that are already close to flat. Lay a straightedge across each one in three directions and keep the pair with the smallest gaps. That sorting step is half the battle, and it costs nothing. If you find a usable pair, buy the bolts on your next hardware run and build it on the weekend. There are more paper projects to try it on in the paper and mixed media section.