Sometimes older is indeed better especially when it comes to using hand tools which is why I started the thread. Nearly everyone who uses hand tools has had a dad, granddad or even a great grandfather who showed them the nooks and crannies of a particular tool and what they were for. I got an idea yesterday to go back to using a miter box on small jobs instead of carting one of my big miter saws around. I mean, to do a lousy 5 or 6 cuts shouldn’t be a big project of stringing a cord and setting up a saw. It took me about 15 minutes to make the box but when I grabbed my 12” Japanese flush cut handsaw to check things out I remembered an old trick my grandfather taught me when I was maybe 6 or 7 years old. The old Good carpenters used to keep their handsaws not only extremely sharp but kept a mirror like finish on the saw. Yeah, keeping it clean does provide for a better cut but it’s the mirror finish that is the most important. When using a handsaw and need an exact 90 degree cut, you don’t have to follow a line but instead, you can simply look through the blade of the saw. No, I didn’t mean look at the blade but through it. When you look at the reflection of the material it’s as if you are looking through the blade and seeing the other side of the material. If the blade is canted or tilted you can see by the reflection of the material in the blade. If the blade is correctly placed, then the edge of the material will appear as a straight continuing piece of material in the reflection. When you cut, the cut will not only be straight but also a perfect 90 degrees depth wise. Even if you’re cutting a 45, the depth cut still has to be 90 degrees and will show in the reflection if it is or isn’t. Try it with a small mirror on a counter top or some straight edge. Pretend the mirror is the saw blade and move it side to side or up and down and you’ll see the different angles that appear. When the line is straight then it’s going to be a perfect 90 degree cut.
I've never found a miter box I liked. I have a true wooden box with the slots cut in it, a plastic version of the same thing, and one of these contraptions: They all seem to have so much slop to them (or the saw blade is so thick) that there is no accuracy. The cut is always too wide with too much variance to it with a bevel to the edge. And my compound sliding miter saw is not for finish carpentry...I would not use it to make picture frames. (Actually, professional frame shops use chops to cut the frame material so they do not chip the patterns.) I like the trick regarding the reflection.
I use my Makita chop saw if there's a substantial amount to be done. I get a better cut by easing the blade down instead of rushing it. I use a mitre saw like the above for small jobs. I screwed a piece of 1/4" plywood to the base so I don't run the saw into the metal. I also glued thin strips of wood to the sides of the saw to fill out the slop of its fit in the guide and keep it lubed with silicone spray. I don't get a mirror finish but I go after any rust on the saw with a power sander and sharpen it myself afterwards. It works for me.
I ended up collecting 2 chop saws and a sliding compound miter over the years. -I have a Makita 10" chop saw that's been beat up over the years (I bought it at Hechingers), and is now used to cut kindling. -I bought a used Makita 8" trim saw mainly because I wanted the portable stand it came with. The angle is tough to set because the tighter you turn the cheap pinch handle, the more it torques the saw out of position. -I have a DeWalt 10" sliding compound miter on a recently purchased DeWalt wheeled collapsible stand. I should have bought that stand a long time ago...it's so convenient. The 8" Makita is the only one I use for "finish work." The other 2 are more rough cut. I never thought of gluing shims to the side of the saw. That's darned a good idea. It's not as though a miter saw has any other uses that the shims will hamper. How far up from the teeth did you glue those shims? I assume you glued 2 shims--spaced apart--to each side?
I went right up under the reinforcing cap that runs along the top.. I forget what it's called. Yes, one shim on either side. they take away some of the depth of cut but I only use it for shoe and small crown and the like.
When I did my bath remodel, I installed a niche like this one: The border of the niche (and the border of my kitchen backsplash tile) is made with "pencil trim:" The corners of pencil trim are almost always cut on a 45° angle for a professional look. The problem is that these pieces are thing and fragile (and expensive), so when you cut them on a tile saw, they often split and break. Then you throw them away. The main reason they break is one end is unsupported when the fragile piece dangles over the edge of the saw's 45° guide as you cut them, allowing for lots of vibration. So I built a tool to do the job. This is a cheap 6" speed square made out of plastic. I screwed a piece of wood to the front of it (middle pic) so that the pencil edge rests flat against the wood most of its length to give it full support where the saw cuts it. The wood also absorbs the vibration. As you can see in the middle pic, there is a slice where the tile saw cut all the way through the pencil edge and into the wood piece, so the pencil edge is 100% supported right at the entire cut...and I can always replace the wood if it gets too shredded. The right pic show the smaller pieces of wood I screwed to the top and the bottom of the back of the square so that the square stays level (does not lean down to one end) and the front edge stays true relative to the saw blade, whether I cut a right angle or a left angle. It works real well. I cut a couple of pencil edges for my kitchen backsplash and I cut (16) 45° ends for the shower niche, and only one piece broke...and that was due to a manufacturing defect in the pencil edge (there was an air pocket right where I cut.)
One thing I’d like to mention is when it comes to trim, a major portion of 90 degree corners aren’t 90 degrees ergo sometimes 2 / 45’s won’t make a tight, puttyless or caulkless corner. On expensive hardwood trim jobs I’d use a bevel finding tool to confirm the corner then if it’s not a true 90 I’d transfer the angle to my trim before cutting. No matter which cutting device one uses, as long as the transfer is followed then there’s no doubt as to whether it is going to be an excellent fit. Yes, it turns a job into a tedious and bothersome venture but perfection can’t be rushed. I once helped trim a 4.8 million dollar home in S. Florida (whilst concurrently working nights as a chef) and every run had to seem totally seamless and every corner had to be glued, tight and the grains as close to being the same as possible. The bad part of that job was that all of the oak trim was milled by my dad so not only did we work with the owner looking over our shoulders but my dad’s very critical eyes were inspecting the work as well.
I do indeed love my silicone spray. I kept running out of it and original WD-40 so I bought a case of each. That said, there are times when going back a few years and having a block of paraffin handy just seems right. A bit of nostalgia perhaps. Ya know, as a young lad watching an old timer sharpening and waxing his blades whilst sipping on a 10 cent bottle of pop kind of thing. Now I’m the old timer and to think back, I’m older now than the old timer I used to watch.