Problem cutting miters on my shooting board

[Tim Andrews]

I love my shooting board for creeping up on a perfect fit. It works great when making 90 degree cuts, both edge grain and end grain. But when trimming 45 degree miters, I can’t get the same results. Even with a freshly sharpened blade, I can’t consistently get the blade to bite into the wood. It just glides across the miter with almost no cutting, more like burnishing.

On the surface it sounds like a sharpening problem, but I keep putting a fresh edge on my blade with mostly poor results. I use a LN #62 Low Angle Jack plane with a primary bevel of 25 degrees and a micro bevel about 27 degrees. Final honing is with a Shapton Ceramic 16000 grit stone, followed by a quick stropping. I use the ruler trick for the back. The blade cuts through paper like butter, and gives great results when face planing and 90 degree end or edge grain.

The current miters that I’m trying to fine tune are not big, just 5/8” square. The wood is Wenge, which is probably more problematic than many species, but I’ve also had this problem with Walnut. I just read that wetting the miter with water or DNA might help, but I’m wondering if there is anything else I can do. Any help is appreciated!

Edit: Sorry, this site decided to rotate my image 90 degrees, can t seem to fix it.

[Jim Koepke]

I use a LN #62 Low Angle Jack plane with a primary bevel of 25 degrees and a micro bevel about 27 degrees. Final honing is with a Shapton Ceramic 16000 grit stone, followed by a quick stropping. I use the ruler trick for the back.

Took the liberty of rotating the image.

Tim's Shooting Board & LN #62.jpg

Using the "ruler trick" on low angle bevel up planes can be tricky. The clearance angle on end grain might be causing the problem you are experiencing.

Would it be much work to remove the ruler trick bevel?

jtk

[Cameron Wood]

Try clamping the piece in position- it might be sliding back.

[Tom M King]

My money is on the ruler trick. I think it's just to get something sharp if you can't without it.

[Jimmy Harris]

Did you advance your blade far enough? I have to advance the blade a lot further with my shooting board sometimes than what I'd use when planing flat stock, especially with miters. Otherwise, it often does as you say, just skims over the wood. I think what happens is if the wood is slightly back when the plane tries to enter the wood, it wants to ride over it and push the wood or the plane back. So sometimes you have to get a bigger bite to get it started. Once it's in the wood, it doesn't want to push it back nearly as much. It's not uncommon for me to advance or retract the blade a couple of times on the same piece of wood when I'm planing it, especially when doing miters, to get the right amount of bite.

[Tim Andrews]

Gentlemen, thanks for the replies. I hadn’t thought about the potential problem of using the ruler trick on a bevel up plane. I can see how that could cause my problem. It might take a lot of work to eliminate the back bevel but I will take a look. I will also try clamping the work piece to make sure it’s not slipping. I did try advancing the blade differently amounts but didn’t get satisfactory results. At least I have a plan going forward, thanks again.

[Prashun Patel]

My money's on the clamping. If you are able to get good results @ 90, your blade should be able to perform @ 45.

@ 45, though, less of your finger pressure keeps the piece registered to the blade than if the piece is registered at 90.

I'm sure you checked this already, but your miter fence is not causing issues, right? If it's not perfectly aligned with the backer fence, it could cause your target piece to "spelch" or miss.

[Richard Coers]

Will that plane pull a nice curl on end grain or a miter on a board in a vise? That is the best place to start.

[Tim Andrews]

Good idea, I will give that a try.

[David Carroll]

My money is also on the clamping. Don't make me bust out the vector analysis!

DC

[Derek Cohen]

One of the issues when shooting mitres, such as those for narrow picture frames or mouldings is that the end of the mitre has no support. By contrast, shooting mitres, such as wide boxes sides, which is across the grain, there is support at the edge (although it is weak and apt to spelch).

In all cases, it pays to chamfer the end of the mitre before making the cut. You do this with square edges (drawer sides and box sides) to avoid spelching; you need to do it with frame and moulding mitres as well. In the case of the latter, it is to add support to the edge, or it will just fold over in the cut, and leave a ragged edge.

A second factor is ensuring that the board does not move. Clamping boards for mitre cuts is important.

The Rule Trick is unlikely to be the cause of a miss cut.

Regards from Perth

Derek

[Tim Andrews]

Update…Sucess!!!

I was able to get back into my shop today, armed with some ideas to solve my problem (well, at least this problem ) I pulled out my sharpening kit to determine how much work would be required to flatten the first 2 or 3 inches on the back of my blade and eliminate the small back bevel produced from the ruler trick. It looked promising, so I started with my 300 grit diamond stone and continued through the grits until I had a smooth, polished back. Total time was only 30-40 minutes.

I resharpened the bevel and put the blade back into my #62, squared it up, and started taking perfect shavings from my miters. The difference was night and day. I had planned on clamping the work piece in place since I thought that could be a problem, but it proved unnecessary as long as I held the piece firmly in place. I was able to quickly trim and fit the miters for my current project. Once it was glued up I pulled out my low angle BU block plane and went through the same process of flattening the back. My other often used plane is a traditional LN bevel down 4 1/2, so I think I’m fine using the ruler trick on that one. If any of you disagree, I would love to hear your thoughts.

I want to really thank all of you who replied. And Derek, thanks for the reminder to cut a small chamfer on the back edge first. I do that for my 90 degree cuts but somehow managed to forget it with the other bigger issue I was having. I frequent a couple of wookworking sites, but this is the place where I know I will get great advice from truly knowledgeable and experienced people.

[Jim Koepke]

Good to hear you got it working Tim.

jtk

[Eric Brown]

So the lesson is keep the back flat. using the ruler trick the bevel raises the angle, and you really want to lower it. A low angle plane or a skewed blade like on a shooting plane would help. The best way to consider the problem is to determine the grain orientation and have an angle that is oblique.

[Rafael Herrera]

Would these premium planes have needed the ruler trick to get them functional?

It seems to me one of those shortcuts that you get stuck with once you start using them.