Workshop Wednesdays - Get Help with Mortising archive
Wednesday 2 July 2014
Derek Jones looks at a couple of new tools that do a whole lot more than their names suggest
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 JigThe 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.