Thread: Splines vs Wall Thickness

Are we talking mitre joints?

Originally Posted by jack620

Are we talking mitre joints?

Oops, yes. Sorry for not making that clear……

It depends on what you are making, but splines are not necessary for most mitred joints (let's see the opinions on that! ).

Cut the mitres, and then "size" them before you glue up. Sizing involves smearing glue on the endgrain, and covering the ends of the tubes. Allow to get close to drying, then add glue and clamp the ends together. Very strong.

Regards from Perth

Derek

Agreed on the non-requirement of splines.

They look great when done well, but are unnecessary.

There was a video recently on gluing end grain¹. It was impressive. Its premise was that end-grain gluing is a no-no and has no strength. The video conclusively proved this wrong and an artefact of old knowledge.

I personally do splines for customers boxes as it adds a pop.... BUT I never do them just as a single bit of wood.


Everywhere I see a nice box and tacked onto the side is this glaring chunk of contrasting timber that's a spline. Yukko!

Much better is to use a piece that is almost identical to the timber of the sides and do a slight (darker or lighter) contrast with a sandwiched veneer. Make a veneer-wood-veneer sandwich and it looks a million bux.

On size? What ever is the most artistic.

Ive done some that are only veneer flitches and they look great!




¹ somewhere here on the forum from Youtube.

Thank you all.

So would it be safe to state, given the size of box that I listed, that a mitred joint on say 10mm thick timber be sufficient without splines?

Yes, all good. I made a slightly larger box like this today. No splines, just sized mitre joints.

Regards from Perth

Derek

G'Day!
You can look at the my theme
https://www.woodworkforums.com/f87/home-knife-237067/

I make almost all boxes from pine, and from pine with very high content of pine resin. Some boards contain a lot of resin - I can notice a turned on headlamp through boards of 10 mm thick.
Last order was boxes with external dimensions 350x110x90 mm. All boxes are mitered without splines and all have the wall thickness 10 mm.
I'm fully agreed with advise of live legend of Pert woodworking Mr Derek Cohen (I say it from heart) regading miters sizing.
But for pine I degrease miters from pine resine with 96% alcohol. Probably it will be good and for other oily woods but you need to try on the offcuts.
For example degreasing of alder with 96% alcohol before glueing make 1-1,5 mm of alder near glue line more clear. Glueing alder with same glue but without alcohol degreasing was not changed the wood colour.

Just to introduce a different approach with oily wood I have successfully used a 45' locking miter router bit with 10mm wall thickness. the stock has to be left wider than needed as the router bit most often tears out on exit. the wood has to be the same thickness for front & side panels.

I use splines of matching wood as it turns out as end grain after i flush cut with the saw I soak it with thin CA glue to stabilize it before sanding works a treat.

I make the odd box from 9-10mm stock with straight mitres and never had problems. Also make trays for boxes from 7-8mm stock and again no problem.

I am not a fan of splines, how they look, but i will add them if i know the box will get moved around a lot or hold heavy objects.

Originally Posted by cava

Thank you all.

So would it be safe to state, given the size of box that I listed, that a mitred joint on say 10mm thick timber be sufficient without splines?

Hi Cava

I made this box today. Mitred ends, sized glue joints, no splines ....



The lid opening is on the side closest to you ...



Here is the finger pull ...





Regards from Perth

Derek

Hi Cava,

I agree with what’s been said above. A couple of extra thoughts, though.

If you’re not completely convinced that “no splines” is correct for a particular box there are other ways to put in splines.
you could cut a slot in each face of the mitres (the surfaces that will be glued together) and insert a hidden spline vertically. Ply is good for this as it is strong and resists snapping apart.

Alternatively, if you plan to line the box you can insert L shaped mitres from the inside by routing a short channel on the inside of both pieces at each corner. Glue up the box as usual then glue the L shaped pieces in. If I do this I cut the L shaped pieces from 3mm ply but you can also buy them pre-made from Jewelry Box Hardware - Box Hinges | Side Rail Hinges | Brass Box Hinges

Lastly, a box making tip I was given many years ago. Decide on the width of your box walls after you’ve thought about what hinges you’ll be using. In my early boxmaking I made some good (for me) thin-walled boxes then couldn’t find hinges that would work.

Best regards,

Brian

That is rather clever.... here is the image:

keys1.jpg