Miter boxes & dealing with kerf

[jarrett]

I've been frustrated with crosscutting straight enough for my liking, and so I bought a miter box to see if that would help things out. The problem is that I'm not really getting any more accurate due to the kerf in the saw. That little extra width created by the kerf means that the sides of the miter box don't really contact the sides of my saw, and so I'm really just floating around in there; nothing is really guided.

Am I expecting too much with the miter box? Or are miter boxes only meant to be used with almost kerf-free saws? Or maybe my saw has too much kerf? Any other handsaw jigs to help me cut straighter?

Also, I tried making a shooting board but I then found out my plane isn't really 90 degrees anyway...

 

[Joe Scharle]

What miter box/saw combination are you using? If it's not a Nobex or Miller-Falls then you may as well be using a speed square as a guide.

 

[jarrett]

Yes, I've been using a $5 plastic miter box from the borg, matched up with an old crosscut backsaw. It's the type that has the 45/90 degree slots in a 3-sided configuration.

I've bought a Jorgensen miter saw in the past, similar in design to the Nobex you mention (but definitely not similar in price)--however, that cuts more crooked than my unguided cuts.

At the prices for those miter boxes, sounds like the choice is more practice vs. electron killing.

 

[Larry Rose]

I use a shooting board even on cuts from the table saw. It's the only way I can get miters to fit the way they should. The shooting board is the most used jig in my shop.

 

[Joe Scharle]

I just noticed that someone on the site has a Craftsman CMS for cheap. A CMS is soooo much easier to align that a SCMS. If you have the time and mechanical aptitude, you could solve your problem with that...

 

[KenOfCary]

I use a shooting board even on cuts from the table saw. It's the only way I can get miters to fit the way they should. The shooting board is the most used jig in my shop.

+1 on the shooting board for tweaking miter joints. Only way to do it. Cut 1/8" oversize and make the perfect length and angle on the shooting board.

I also use a bench hook with a 2" square piece of poplar on the end opposite the hook. This has carefully cut 90 degree and 45 degree kerfs in the 2" block. These kerfs are exactly the size of the kerf of the backsaw I cut them with and I use them to align and cut small pieces similar to using a miter box. (Sort of a one sided miter box, but the kerf is exactly the right size.)

When it gets worn, I just replace the poplar strip or make a whole new bench hook from scratch.

Cheers - Ken.