Advice needed from more experienced furniture makers - should I mitre the corners?

[Sawdust=manglitter]

Shamefully I’ve not worked on any more of the TV cabinet/sideboard for a couple of years since the main cabinet was complete and living in the house. I could use the excuse of a lack of time or other priorities, but truthfully it’s more than likely because in the back of my mind I didn’t have the confidence to finish off the doors and drawers and didn’t want to fudge them up.

Well enough’s enough and the ‘client’ (SWMBO) at the very least wants the doors to be finished off!! I have been prohibited from starting any other projects until I’ve finished the doors, so best get cracking with them.

The mortise and tenon joinery is done on both door frames, and I’ve also just finished flattening and sanding the 10mm thick book-matched burr oak panel’s I bandsawed from a larger oak burr I have a couple of years ago.

Here are the oak burr panels after a spray of water to raise the grain between sanding grits...

Here’s one of the dry fit (but unplaned/unsanded etc) quarter swan oak door frame laid over the burr oak floating panel...

And here are the loose fit frames against the cabinet (please excuse the background mess)...

So as the ‘client’ found it difficult to picture my design suggestions so I offered to mock up the design using the Photoshop Mix app on the iPad (which is surprisingly easy to use, but time consuming) and here’s the result...

Anyways, I planned on using African Blackwood to make the handles, hopefully make hinges, and to also frame the oak burr floating panels. To finally we come to my question...

... based on the mortise and tenon joinery of the main frame I wasn’t sure if I should mitre the corners of the African Blackwood where they will be inset within the oak door frame (if that makes sense)? Based on someone else’s much greater experience than mine, would the wood movement of the oak door frame mean that the mitres would open up in future? If so, what would be the best method of insetting the African Blackwood frame? Note that the African Blackwood would likely only be 10mm wide and maybe 7 or 8mm thick. In my mind it will set off and emphasises the incredible grain of the oak burr panels, so I would like to incorporate them somehow, but would ideally like to prevent the opening up of gaps between the oak frame and the Blackwood due to seasonal movements etc. I’d love for this cabinet to last a lifetime, hence wanting to do a ‘proper’ job of it, something I can be proud of.

 

[thetyreman]

from what I am seeing you could scribe the blackwood door panel trim instead of mitring it, then if it does move you won't see any gaps opening up, that might be the answer you are looking for. I can only speak from working with gaboon ebony but that is unbelievably stable wood, so mitres opening up especially on something that is only 10mm wide shouldn't be an issue, hope that helps,

regards,

Ben.

 

[custard]

Nice project.

The Edward Barnsley Workshops do a lovely cupboard with solid burr panels.

To make it obvious that it's solid burr rather than veneer, the panels have a subtle cushion profile worked into the front face. This isn't clear in the photo but in real life it really jumps out at you. However, it's an absolute pig to make because the cushion profile needs forming with a gazillion strokes of a hand plane, and to avoid tear out you have to re-hone every minute or two.

Anyhow, in answer to your question, yes mitred Blackwood will be fine! Some super obsessional types prefer to fit mitres by taping the outside mitres in place and then fitting the sections between them, ticking the mitre on a shooting board or, every bit as good, a disc sander with 240 grit paper.

Incidentally, even small, cheap disc sanders can cut truly impeccable mitres. You clamp a bit of wood on the table as a fence and tinker until it's absolutely spot on, then you can adjust the length of mitred component by lightly kissing them against the spinning disc. In my experience this method allows you to remove finer increments than even the finest set plane on a shooting board.

Good luck!

 

[bjm]

You say the cabinet has been in the house for years. Have you kept the wood for doors in the same room as the cabinet? If not I would condition it to an equivalent moisture content before doing anything else (this will buy you some time ) We tend to keep our houses relatively stable so seasonal movement is not necessarily a big problem, but you will know how your rooms are more than us. If the door wood has been kept in your workshop you will get some shrinkage across the grain. Wood moves very little along the grain so I wouldn't worry too much about the mitres opening up - if you butt-join it the blackwood can shrink across tha grain and show a gap as well. Either way I wouldn't expect it to be noticeable.

 

[Cabinetman]

I wouldn’t worry about that small section moving, I’m sure it will be fine.
Thanks Custard I don’t know why but I would’ve never thought of doing it that way. Homemade jigs up to now.
Just a thought about the aesthetic‘s/design of the two central members of that piece you showed us, it looks wrong to me, I think the stile should go straight through and the two small horizontal rails should infill. I like the cushion effect though, I’ve got some really big chunks of oak burr which I cut slices off for box lids etc, so I will try it next time.. Ian

 

[Droogs]

As you have solid, pehaps have the doors on the other side and use the gap in each corner as the means to open the door instead of a knob or pull etc

Even use cold pour bronze powder and resin to fill it and then create the pull with that, so it feels like solid metal but fits the edge exactly

 

[Sawdust=manglitter]

I know I was probably overthinking it with the mitres, but I wasn’t sure how much movement to expect there over the years. Thanks for all of the great advice!

from what I am seeing you could scribe the blackwood door panel trim instead of mitring it, then if it does move you won't see any gaps opening up, that might be the answer you are looking for. I can only speak from working with gaboon ebony but that is unbelievably stable wood, so mitres opening up especially on something that is only 10mm wide shouldn't be an issue, hope that helps,

When you say scribing it, do you mean like a butt joint? Butt jointing it was the only other method i could think of doing it, but having read all the advice above i’ll likely try mitring the corners now.

To make it obvious that it's solid burr rather than veneer, the panels have a subtle cushion profile worked into the front face. This isn't clear in the photo but in real life it really jumps out at you. However, it's an absolute pig to make because the cushion profile needs forming with a gazillion strokes of a hand plane, and to avoid tear out you have to re-hone every minute or two.

I wish I’d bansawed the burr oak thicker which would have given me the flexibility to try something different like that, but I’ve got a finished thickness of 10mm which still looks pretty good to me. In terms of making it obvious that it’s solid burr, I’ll be leaving the little gap to one corner and I won’t be filling any of the cracks etc with resin or something.

Anyhow, in answer to your question, yes mitred Blackwood will be fine! Some super obsessional types prefer to fit mitres by taping the outside mitres in place and then fitting the sections between them, ticking the mitre on a shooting board or, every bit as good, a disc sander with 240 grit paper.

Incidentally, even small, cheap disc sanders can cut truly impeccable mitres. You clamp a bit of wood on the table as a fence and tinker until it's absolutely spot on, then you can adjust the length of mitred component by lightly kissing them against the spinning disc. In my experience this method allows you to remove finer increments than even the finest set plane on a shooting board.

That’s a great tip for refining the mitre. I already have a disc sander, so I shall likely be utilising that method. As always, thank you for the great advice Custard.

You say the cabinet has been in the house for years. Have you kept the wood for doors in the same room as the cabinet? If not I would condition it to an equivalent moisture content before doing anything else (this will buy you some time ) We tend to keep our houses relatively stable so seasonal movement is not necessarily a big problem, but you will know how your rooms are more than us. If the door wood has been kept in your workshop you will get some shrinkage across the grain. Wood moves very little along the grain so I wouldn't worry too much about the mitres opening up - if you butt-join it the blackwood can shrink across tha grain and show a gap as well. Either way I wouldn't expect it to be noticeable.

All of the wood has been kept in it’s intended room (for the last couple of years, to the dismay of the OH), and is also always brought back in the house after working it in the workshop. So I’m not too worried about any serious movement as it’s already acclimatised. But yes, good point about the but joint too, thank you.

Just a thought about the aesthetic‘s/design of the two central members of that piece you showed us, it looks wrong to me, I think the stile should go straight through and the two small horizontal rails should infill.

Thanks Ian, I’m not entirely sure what locations you are referring to regarding the aesthetics?

I like the cushion effect though, I’ve got some really big chunks of oak burr which I cut slices off for box lids etc, so I will try it next time.. Ian

As I mentioned above, I wish I had but the burr panels thicker to give me more flexibility to do something different like the cushioned profile.

As you have solid, pehaps have the doors on the other side and use the gap in each corner as the means to open the door instead of a knob or pull etc

Even use cold pour bronze powder and resin to fill it and then create the pull with that, so it feels like solid metal but fits the edge exactly

Thanks for the suggestion. I did think about using that gap as a pull of some kind, but I’d like to make some nice Blackwood handles which would match the Blackwood hinges and the framing of the burr panel, so decided against using the gap as a pull location. As I mentioned above, I don’t plan on using any resin on the burr panels, I will try to keep it as natural looking as possible.

 

[TheTiddles]

Are you leaving the hole in the corner of the panel? As it’s flat I’d be more tempted to use veneer and save that lovely burr for something it fits perfectly
Aidan

 

[Cabinetman]

Sorry Mangler, was referring to Custards door with the four panels.

 

[Sawdust=manglitter]

Are you leaving the hole in the corner of the panel? As it’s flat I’d be more tempted to use veneer and save that lovely burr for something it fits perfectly
Aidan

I personally quite like the hole to the corner. It also helps show the thickness of the burr and highlights the fact that it’s a solid panel rather than a veneer.

Sorry Mangler, was referring to Custards door with the four panels.

Ah, makes sense now!