The Mason’s Mitre
You’ve probably heard of the the Mason’s Mitre before. It a method of continuing a moulding or rebate around a frame with just square shoulders. You effectively carve the profile around the joint rather than scribing or mitring. I saw these examples at the Museum of Somerset in Taunton.
Or that is, I assumed it was a Mason's mitre. The internet seems to think differently. Now, I don't really care about terminology that much. I say rebate, you say rabbet. I scribe, you cope. Who gives a damn!
What I found interesting was how the name has been carried over from earlier architectural forms and now seems to be a term for post form laminate worktop joints and similar profiles.
What's odd is that modern versions are a completely different type of joint. Take a look at the worktop joint. These are made with proprietary jigs and robust electric routers. I see this as a butt mitred joint, not a mason’s mitre. A more traditional version would be a mortice and tenon frame that has a cock beading profile on the inner face. You can’t scribe a cock bead, it’s impossible, so you mitre the bead and remove moulding to allow the shoulder to fit. It’s harder to describe than it is to show it. See below.
A video often does a better job than tripping up on words.
It’s the same situation on any profile that rises and falls on the flat face. An ogee on the flat face has the same issue. It’s very unlikely you’ll need to use the mason’s mitre though.
If you use an electric router after a frame is glued up to form a rebate, the chopping out you do to square it up, that’ll be a mason’s mitre (of sorts). If you make mortice and tenon frames in medieval styles, you’ll use mason’s mitres.
I have a hunch about the mason’s mitre, if you’re more learned than me, perhaps you can contribute. We often see this method of joining on heavily carved and moulded ecclesiastical work. Would the carpenters or joiners with their more robust tools and skills make a simple mortice and tenon frames and then had it over to the the carvers who would then use scratch stocks and carving tools to add the decoration? Over time, as carving was required much less, joiners and furniture makers developed much more sophisticated ways of creating joints without exposing end grain. Just a thought.
And the museum is good, well worth a visit. It’s free to enter although I recommend leaving a donation if you are able.
