Do you need to strengthen a mitre joint

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Raw69

Established Member
Joined
9 Nov 2019
Messages
26
Reaction score
2
Location
Essex
Hi

Third project, as got some material left over from the cabinet. Dimensions are only 450x500. Would I need to add strength to this mitre joint on such a small piece?
 

Attachments

  • 781C26C9-552E-4CC1-B9C7-92921500AED3.png
    781C26C9-552E-4CC1-B9C7-92921500AED3.png
    856.2 KB · Views: 325
I'm no expert, so take this with a pinch of salt, but in my limited experience, mitre joints are only good for picture frames. They seem to me to have little strength, and are 50% end grain. Even picture frames often have splines added, for a bit of extra strength.

But as I said, I'm no expert.
 
For a design like that, yes, definitely. But it doesn't need to be overkill, a row of biscuits will do just fine.
Your bigger problem will be clamping it, I think.
 
I assume as long as I get the right angle when drilling, that simple dowels will work just as well. I have limited tools
 
Raw69":2c1ddu2h said:
I assume as long as I get the right angle when drilling, that simple dowels will work just as well. I have limited tools

They won't work as well as a biscuit or a cross-spline, because of the grain direction, but they will be better than nothing.
 
Mitres aren't easy. I know they look easy, but they will test your planing skills to breaking point. A not-quite-right mitre looks terrible. If you are a beginner with few tools, then this is quite an ambitious thing to take on. Have you considered box joints or dovetails? Second best joints there are much more flattering than second-best mitres.
 
I’ve tried dovetails and come to the conclusion I need to visit an opticians. And although I like the look of box joints, I prefer the larger 1-1.5 inch, which I could do with the router but would need to set up a jig etc.

As for tools I do have a table saw, hence the view that a mitre joint might be easier. Re the biscuits, is there a way to cut these with a route on a mitre edge? Or is there a cheapish decent jointer out there? Budget would be south of 100 quid.
 
Well you are not going to get a Mafell for that, but there are plenty of others in your price bracket, it's just a matter of choosing one. Bear in mind, though, that with most things in life, you get what you pay for.

My first BJ was a Freud, £120, probably over 30 years ago.

Link
 
What material are you using? if its solid then in a sense a mitre would be 'easier' but if its a faced board then it would need to be perfect or look awful.
 
Are you planning on fitting a back panel between the top and the shelf?

If so then a plywood back panel glued into a housing in the top and sides will give much more strength than any joinery product fitted inside a mitre joint. The real reason biscuits, dominos, dowels etc are used it to help align the joint whilst assembling, they stop the surfaces sliding against each other as you crank up the cramp pressure. They aren't critical but they do make life somewhat easier.

If I was making that I probably wouldn't bother with cutting biscuit slots, I'd use the masking tape method of folding the joint together to glue it up. I would also add some interest to the design with a sliding dovetail joint for the shelf, this is not much more work than cutting a standard housing joint but would require tuning up and sliding in after the main carcass was glued.

If you were feeling particularly adventurous and wanted to repeat the dovetail detail you could always reinforce your mitres with some sliding dovetail splines.

That looks like a bedside cabinet which don't really see much abuse so most joinery methods will be fine.
Lots of possibilities, the only limit is your imagination.
 
mitred dovetails would be the most elegant solution here, and a stopped housing dado so that the front of the dado is hidden.
 
The problem you'll have is that people will always go to lift that from the top.

If you don't mind dowels, how about screws and plugs?

If you don't have a biscuit jointer, then you could probably route out a few splines. As the face of the mitre will be hidden in the end, you can just screw a plywood jig to it to guide the router.

Another idea is just to glue it up with expoxy, and then add some long blocks (secured to the side and top) from the back that stop halfway way, so they're not visible.
 
Using 30mm solid oak.

Not planning on a back board.

Once in place it’s not going to get moved too much, so think I’ll give the router / splines approach a go.

Cheers for all the feedback, wish me luck.

Ps just seen a few vids on the sliding dovetail splines. These look great, might need to make a router table for my handheld
 
Re gluing up - I'm a great fan of gluing temporary 45° blocks either side of a mitre so that you can apply a g-cramp directly across the joint just like this:-
IMG_0084.jpg
Your spline will keep it all in line when the pressure is applied.
Brian
 

Attachments

  • IMG_0084.jpg
    IMG_0084.jpg
    210.6 KB · Views: 234
Steve Maskery":2oi9b8aa said:
For a design like that, yes, definitely. But it doesn't need to be overkill, a row of biscuits will do just fine.
Your bigger problem will be clamping it, I think.
Yep, perfect. The ideal way to cramp that would be to insert a removable fourth side at the bottom and use a few webbing cramps - Rob
 
MikeG.":14h9htgw said:
Mitres aren't easy. I know they look easy, but they will test your planing skills to breaking point.
Long mitres like this are a nightmare to do freehand, but if you concoct a really accurate jig to hold each section, then the job becomes a lot easier - Rob
 
Thanks to tomthumbtom8 (sorry I don’t know how to link a username)I think I’ll copy his idea if using resin spines, that way it’ll tie into nicely with the other items I’ve put together.

His fantastic work below.
 

Attachments

  • A8FB0DEA-3535-4490-8A82-51226D040A56.jpeg
    A8FB0DEA-3535-4490-8A82-51226D040A56.jpeg
    39.5 KB · Views: 67
I made a console table using mitre joints, and in the process of making a second.

Biscuits appear to be good enough. I can stand on the table no problem and I’m a big lad :D

As far as clamping, I used ratchet straps with blocks at the corners.
 
Quickben":20n2inyw said:
Biscuits appear to be good enough. I can stand on the table no problem and I’m a big lad :D

As far as clamping, I used ratchet straps with blocks at the corners.
Wot Mike G and I said ^^ - Rob
 

Latest posts

Back
Top