The press and tub is now complete, again following the plans from the Aldren Watson book. i used pine for the tub and some hardwood off-cuts from the local DIY shop for the press. I had some trouble finding the bolts, or rather finding bolts that were threaded full or nearly full length. In the end they came from a local timber merchant where I went to look for hardwoods and spotted them unexpectedly lying on the counter.
It was challenging for somebody of my fairly modest woodworking skills to get the tub exactly square. In fact it isn’t critically square but seems to work well enough. The hole for bolt to pass through in the jaws needs to be a lot larger than expected (my bolts are 10mm and the holes are 12mm/13mm in diameter) otherwise the bolt action is so stiff that the jaws cannot be moved. I was concerned that they would be wobbly but once in place with one side fixed to the tub the action is smooth and perfectly solid.
The jaws using 200mm bolts with the fixed jaw 50mm and the moving jaw 35mm thick give a maximum opening of 100mm which is larger enough for my purposes and should allow for a book of 50mm thickness with room for backing boards.
Tub and press with piercing board.
Tub and press side view.
Close up of threaded bolt. I cut a groove in the head of the coach bolt with an angle grinder to allow a screwdriver or coin to fully tighten the jaws.
Close up of threaded bolt from the back show the inlaid nut held in place with epoxy glue.