What are my views on dovetailing in metal planes? A question recently put to me.
Well, what are dovetails in metal planes? I would describe them as an elaborate form or riveting two pieces of metal at right angles together. From my point of view this does not compare with the strength from casting, welding or silver brazing. However there are some advantages to be gained from dovetailing, such as access to the mouth and achieving a better fit for the filling. It can also be cosmetic, such as brass on steel, though when working with steel sides and steel bottom it would seem ironic the time and trouble spent to produce an invisible result.
In a short article by Nigel Lampert on British Metal Planes he leaves two questions open. One of which was “from which trades did the skills used for making dovetailed planes emerge?”. Well, I can only guess at the answer. I would say that the first tradesmen were Cabinetmakers. Stewart Spiers was a Cabinetmaker and many of the planes that I have seen appear to be user made. When you come to think about it, all you would require is a metal saw, file, drill and patience.
I don’t think there was a problem as far as skill. I feel that most Cabinetmakers have the necessary dexterity. In my days as a Cabinetmaker I can remember homework projects appearing during break periods, so it is easy to imagine these early journeymen producing their little bundles of metal during moments of respite. To them it would also seem logical that any form of jointing combined with riveting would use a dovetailed format. They would have discovered that metal lends itself to dovetails more readily than wood. The principle of dovetailing in wood is that the strength is two dimensional because the third dimension depends on glue. However, in metal we can file a secondary dovetail form on the pins and by allowing excess material on the dovetail this can be peined to fill in the voids created by this filing, hence we have this impossible joint.
I am privileged to know someone who worked for Norris up until the 1940s and he assures me that all dovetailing was done by hand, and it would seem that many commercial companies in the 19th century found fabricating by dovetail convenient. For my part I find dovetailing compatible with my quality and objectives.
Appeared 1997 – Toolshop Auctions Catalogue