What's the best way to make mitred joins for keepsake box?

[kgill]

Hi, having just purchased a mitre saw I thought I'd make a small box this weekend with mitred corners. However this got me thinking what is the best way to cut accurate mitred joints?

1. with the saw vertical but at a 45 degree mitre angle - with the timber face against the fence
2. with the saw perpendicular to the fence but at a 45 degree bevel and the timber face on the bed of the saw
3. or... use a table saw with a sled and the blade at 45 degrees

I'd be intrigued to see what you all think.

 

[johnnyb]

It depends on the accuracy of each method as accuracy on a mitre has to be perfect. So most mitre saws are off. Even when adjusted there not quite right. Equally with a table saw. I no joint exists on its own so the item needs to be the same size as its opposite number. A method where a couple of the variable are nailed is best. Say a perfectly square perpendicular edge that's the right size or some other eight from ten.

 

[MarkAW]

Shooting board?

 

[Blackswanwood]

Shooting board with a donkey’s ear does the job nicely.

 

[recipio]

Ideally a quality miter fence on the table saw set to 45 degrees. Check that the blade is perfectly at 90 to the table with a digital inclinometer and the wood should be clamped down.
Failing that either option on the miter saw will work but again the wood should be clamped down.

 

[Orraloon]

As others have said unless the miter saw is a good one and well set up it will not be accurate enough. Have a trial run with some pine as it will be a good exercise in setting up the saw and learning about miter joints. I use the tablesaw like recipio says but with a sled. Shooting board is the traditional way working to knife lines to ensure opposite sides are exactly the same length.


Regards
John

 

[skeetstar]

Ideally a quality miter fence on the table saw set to 45 degrees. Check that the blade is perfectly at 90 to the table with a digital inclinometer and the wood should be clamped down.
Failing that either option on the miter saw will work but again the wood should be clamped down.

I've got a makita mitre saw that will cut accurately, but as you say, the work needs to be clamped. If not I've noticed a tendency for the blade to 'drag' the timber out of the desired angle... not much, but enough to leave the faces in need of tidying up. Bit hard to explain, but if it's happened to you, you'll know what I mean.
Oh and I always use some sacrificial timber in place to guard against tear out.

 

[Cabinetman]

They look simple but Mitre joints are difficult to get right, and difficult to cramp, I would suggest you try lap joints.
Ian
Edit, sorry I said that without knowing your skill level.

 

[Chubber]

No-one has mentioned a router and 45 degree chamfer bit?

As said above, identical lengths are paramount so if the stock is wide enough joint 2 sides from one piece and run through a table saw? That's how I like to do pairs of tenoned rails.

 

[HamsterJam]

I always try to cut opposite sides together so I can ensure they are exactly the same length. I have used double sided tape to stick them together or as @Chubber suggests also cut the mitres then ripped the stock lengthwise to create two opposing sides.
I guess a mitre trimmer is the ideal tool to get exactly 45° but I don’t have one (yet?) and instead cut my stock slightly too long then use the belt sander with a fence set at 45° for final ‘trimming’. I calibrate the fence to the correct angle by sanding and measuring offcuts.

 

[recipio]

I recently invested in a Jessem table saw miter fence. Apart from being accurate it will clamp the wood and cut to a stop up to 46". A stop is essential in my view - it stops the wood sliding laterally as well.

 

[andrew_2]

Hi kgill. My sixpenceworth. I have an old table saw that doesn't cut 45's nicely at all. So I decided to make a donkey's ear shooting board for a small box project like yours. A youtube search came up with this alternative: (not a donkeys ear)

It works extremely well. The only irritation is that you have to concentrate on keeping the plane tight against the slope support.