Sunday 4 November 2012

Making Curved Architrave

The main job I've been on has given me plenty of unusual projects where I've had to do some thinking. Curved architrave around an arched opening is the latest one.
I formed the arched opening some months back where the curve was to be semi-segmental, but since then the customer has changed their minds and decided that they want it to be semi-circular. I'm to build the architrave out and then we're to bring the plasterwork out to match at a later date.
Clamping boards up - the red light is from the heater.
 Making anything curved on site is harder than you might think and involved many more steps than putting architrave around your standard square door frame.
The architrave has to match the original architrave mentioned in a previous post. This is built up out of two parts. A thin flat layer with a bead on, then a narrower moulded section that is fixed to the outside of it.. To start to make the curved architrave I had to make the flat section first. I decided to leave the bead off for now and attach that later, as no router cutter would shape it in the same way as it is on the original (two cove cutters wouldn't look quite right). I planed the timber down then clamped boards up together and left them to set (with a heater chucking some heat on to them - the barn isn't very warm!).
Rough cut with a jig saw
 I then rough cut the curve with a jig saw. Drawing the lines on with a homemade compass and pencil. If you were just making one side of something curved you might be able to cut it free hand but any imperfections and flat spots would stand out on what is to be matching sets.
Using a homemade router jig
 To make sure every piece was identical I made a jig for the router with two points for it to be fixed to for each cut (inside and out). I screwed the wood down to prevent it moving while I routed it. The screw holes on this first piece will be covered by the second set of architrave.
The first layer fixed around the arch.
I then fixed this architrave around the arch using plenty of adhesive and pins.
Same jig but with another point to make a narrower set of architrave.
 The second set of architrave used the same jig but with the addition of some extra points to fix it down. I also routed a large groove in the ply base of my jig so a bearing guided cutter would then run against it to create the moulding without having to take it off the ply. I used my larger router for this and as the cutter was new it cut the moulding cleanly in one pass.
The second set fixed on top of the first
 I then fixed the second set of architrave on top of the first and switched the kettle on. This wasn't for a drink but instead to fill a 4" pipe full of hot water. The only way I could think of bending the beading to fix round the first set of curves. This involved leaving the wooden bead in the pipe to get hot and steamy before running up stairs to fix it on. I had to move pretty fast as it soon cooled down, it also had to be in quite short sections so it didn't twist as I fixed it. Only managed to complete one side last night though as it got too dark and the lights weren't working on site.
It was dark when I took these pictures but I'll get some close ups next week. The beading is fixed on these as well. It also needs a good sanding down.
A couple of day of firsts - Never made curved architrave before and I've never bent wood using hot water.
I really enjoyed the challenge of this project, even though many people won't know the effort that went into creating a seaming simple set of architrave. I love the fact that after over 10 years in the trade there are still completely new projects to test my skills and keep my brain working, I can't think of a more enjoyable job than being a carpenter!


  1. Clever stuff. The curved architrave will transform that archway.

    1. Cheers for your comment! I think it will look different now. It also means the decorator will have an edge to finish their wall paper to.

  2. My goodness, you're amazing!

    1. Thank you! Not sure about amazing though...


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