Q&A / 

Compound Miter Saw

DEAR TIM: A compound miter saw has bubbled to the top of my power-tool wish list. I think I need a compound miter saw to put up some crown molding and wonder if it is necessary. Would it be better to get a sliding compound miter saw if I do go ahead? How do I discover the best compound miter saw? Reading several compound miter saw reviews has me pretty confused. Andy D., Nashville, TN

DEAR ANDY: I am sorry to hear about your confusion after reading the tool reviews. That is unfortunate as a compound miter saw is a significant investment, and you do not want to make a mistake when you are buying a specialized tool.

Let's discuss compound miter saws and crown molding first, since that seems to be the reason you are thinking of buying this power tool. A compound miter saw is a specialized saw that allows the saw blade to pivot in two different ways at the same time. This allows it to make a compound cut as you find on the ends of crown molding and roof rafters that intersect a hip or valley rafter.

You can see the saw blade is angled two directions at once. The shiny pistons are a giveaway that this is a sliding compound miter saw.  PHOTO CREDIT: Brent Walter

You can see the saw blade is angled two directions at once. The shiny pistons are a giveaway that this is a sliding compound miter saw. PHOTO CREDIT: Brent Walter

Compound cuts are very rare in typical residential construction. The vast majority of angled cuts in a home, such as miters on baseboard and window and door trim casings, are made with the saw blade cutting down through the material at a 90-degree angle, but the saw is rotated at an angle to make the miter. This cut is possible with a compound miter saw when the saw is set up like a regular miter saw.

You can cut crown molding without a compound miter saw. All you have to do is place the crown molding in the saw so it thinks it is already hanging up against the ceiling. The table of a regular miter saw and the vertical fence that rises up from the saw table are oriented at 90 degrees to one another, just like the typical wall / ceiling interface so it is easy to hold the molding at the funny angle.

If you put the crown molding upside down in the saw and hold it in the saw the same way it will be installed it your home, all you need to do is rotate the regular miter saw to the correct miter angle and make the cut. Because the crown molding is being held against the saw fence tilted down at an angle towards the table of the saw, the resulting cut is a compound cut even though you were not using a compound miter saw. Isn't that amazing?

I own a sliding compound miter saw and must tell you it is a fantastic tool. But the reason I love it is that the combination of the 12-inch blade and the sliding function allow me to make precision cross cuts on material as wide as 14 inches. I liken sliding compound miter saws to small portable radial arm saws. It can't do everything a radial arm saw can do, but it sure comes in handy most of the time.

A sliding compound miter saw is a wonderful tool to have around the shop or for a serious do-it-yourselfer. You will use it for many purposes, but don't buy it just to cut crown molding. There are many finish carpenters who love their compound miter saws and use them regularly to cut crown molding. But realize that the master carpenters of yesteryear installed crown molding without this fancy tool, much less a saw powered by electricity!

The best compound miter saw is a pretty subjective piece of advice. This is possibly why you had trouble with the tool reviews. You can have five different carpenters test the exact same compound miter saws in a side-by-side comparison and come away with five different first-place winners.

The weight of the saw can be an issue, the size and horsepower of the electric motor, the range of cutting angles, even the type and shape of the handle can make a difference to the user. One thing my miter saws must have is the ability to make cuts past 45 degrees. All of the miter saws I own can make cuts up to 50 degrees. This comes in very handy when installing crown molding on outside corners. Frequently the needed angle to make perfect cuts is 47 or 46 degrees.

Price is often a very accurate measuring device when you are comparing the quality of compound miter saws. This is a very competitive marketplace, and there are enough manufacturers that they have to create crisp features that set them apart.

If you are a manufacturer that wants to deliver exceptional quality, then you will probably include high-quality parts that cost more. These costs result in higher retail costs to the consumer. Over the years, I have never been disappointed when I have paid more for a high-quality power tool. I want to know it will be durable, and that it will produce accurate work. Those things are very important to me.

Column 712


2 Responses to Compound Miter Saw

  1. Biggest problem on compound miter saws is ensuring you can find a true zero angle (90 degree as starting point on two axis's ). Even a 0.5 degree off from zero before adjusting will result in a poor fitting or bad cut. All saws can be adjusted toward a zero, but some are just too sloppy right from the factory.

  2. Rollin makes a good point about miter saws never quite being true. It's a good idea to check the fence and table for being level when you take it out of the box. With a bit of tuning, you'll be cutting perfect miters every time!


Leave a Reply

You have to agree to the comment policy.