Workshop Wednesdays – Get Help with Mortising

Monday 9 July 2018

On the face of it, you could be forgiven for thinking that these two items have very little in common. One is used in connection with routing – a noisy and antisocial pastime – and the other in more refined circumstances, often to a soundtrack of a string quartet.

Apart from being tools that, to be honest, you don't really need, they do in fact perform very similar tasks. The Trend Lock Jig speeds up the process of chopping mortises for locks while the Veritas hinge mortise plane does pretty much what its name suggests. With nothing to compare them with, I won't be looking to make any judgement as to their performance in respect of similar alternative devices, but merely look at the advantages of these to decide if, in fact, they deserve a place in your tool box in the first place.

The main similarity between these tools is that they simplify processes that can already be achieved by other means. Deep lock mortises may not be the mainstay of every cabinetmaker, but as sure as eggs are eggs, there will come a day when you have to chop in a lock or two and I reckon you'll be wishing you had a little helping hand when that day comes. In cabinet work, a butt hinge laid flat is only one of a huge repertoire of possible configurations for swinging doors and panels and not all are what we might class as 'joinery spec', but before we jump to any conclusions, let's have a look at the tools in more detail.

Trend Lock Jig

The top plate of the jig is made from a sandwich of dense resin with aluminium faces. A pair of insert plates are calibrated to make setting the jig quick and easy using the specified 12mm diameter cutter in conjunction with a 30mm guide bush. The jig is adjustable to work on doors of between 30 and 80mm thick, which is your first clue as to where else it might come in handy.

I don't know about you, but I haven't fitted locks in many doors that are 80mm thick, but I have been known to cut mortises in timber this size. The jig works off centrelines – my personal default setting for laying out – and is engraved with numerical values that correspond with the cutter and guide bush combination suggested. All offsets are done for you so you can dispense with the calculator and rule. Just mark the centrelines in both axes and you're away. Or, at least, you would be if the ones engraved on the jig extended down the edge of the top plate. I added my own, which I reckon was better than using the setting blocks provided. These are fine if you can factor in the thickness of a pencil line in your location of the mortise.

To get the best possible results with the jig, use a centring pin to set the guide bush. A guide bush only needs to be offcentre by 0.5mm to result in a mortise that is 1mm wider than the setting on the scale. This may be acceptable for a mortise lock body but not for the faceplate, which brings me on to mortises for the SOSS hinge. Oh yes, this lock mortise jig doubles up nicely as a hinge mortise jig.

Veritas hinge mortise plane

In essence, the hinge mortise plane is a stretched-out router plane. It uses the same height adjuster as the router plane and the same tooling, so if you have one of these already, there's definitely some common ground covered. If not and you have the need to cut flat hinge mortises in any great numbers, this will certainly speed up the process if, and this is the decider, you really do need to be certain of equal depth for each one. Let me explain. Even hand tool users sometimes want to get the job done quickly so if, like me, you like to hack away at the waste first and leave a bit to clean away neatly to the line, the hinge mortise plane will do just that. Starting from scratch is a little slower as you need to define the walls of the mortise regularly throughout the process. The full depth of the cut needs to be crept up to and reset each time for the next mortise. The depth stop does make this easy but it's not really an efficient system for identical repeat mortises. Just like the Lock Jig from Trend, this plane has a function way beyond what the name suggests.


Both of these tools come with a set of excellent instructions that will help you achieve great results the first time you use them – there's no learning curve. As tools bought for one use in mind, I'd say the Lock Jig and hinge mortise plane are limited in their appeal. However, think of them as a mortise jig and mortise plane and I think you'll agree their potential knows no bounds. They appeal to two different schools of thought: the hand tool crafter and the power tool technician. Whatever camp you're in, don't be convinced of a tool's potential just by its name. I still stir my paint with a screwdriver.