Ways to Cut Crown Molding
Pros discuss various methods. May 4, 2005
How do you cut your crown - on the flat, using compound cuts, or upside down using the fence and base? I cut mine upside down. Too many saw adjustments doing compounds. But someone told me they don't change the bevel part of the saw, they just flip the crown onto its face. I don't cut my crown on the flat, but never heard of this.
(Cabinet and Millwork Installation Forum)
From contributor P:
My preference is to cut upside down, bedding it to the fence and table and using a standard miter saw. This is fine for architectural crown and paint grade stuff. But for cabinet crown, I use my scms and cut it on the flat. Very accurate and less chance of it moving while cutting, especially if you use the hold downs. As far as changing the bevel angle when cutting on the flat, the only time this needs to be changed is for a 22 1/2 degree angle rather than a 45. It depends on what type of crown I am cutting if I flip it over onto its face or turn the table. Not all crown can be flipped due to varying thicknesses on the face.
From contributor J:
I cut my crown upside down on a miter saw. I also always hammer and hand sand the joints.
From contributor B:
I use a Dewalt 12", cut upside down and backwards using crown stops, with an 80 tooth TCG with 5 degree negative hook. Very nice cuts, great joints. I screw the crown on through a beveled lip nailed to the cabinet top. Draws up tight, and no nail holes to fill.
From contributor G:
Actually, cutting in position is just as accurate as cutting on the flat - if you use a proper crown stop that supports the material continuously across the front edge. And the only reason to cut on the flat is if the crown molding is too big to cut in position. Cutting on-the-flat is much more time consuming because you must change the bevel and the miter frequently - both the bevel and the miter change substantially for each degree the corner changes - the bevel and miter for a 90 degree corner are so different from an 88 degree corner that the pieces won't fit tight. Yes, you can avoid flipping the bevel for every cut, and only changing the miter, by whirly-birding the molding. You can't turn the material over, from face to back. When cut on-the-flat, most crown molding must rest on its back. There are some profiles, mostly polyurethane, that are designed to be cut while lying flat on the face.
From contributor H:
Some crown mouldings will fit under a saw allowing you to cut upside down with a 45 angle on the saw. There are also large crowns that won't fit under any saw using this method. These have to be cut flat. There is not much difference between the two methods as far as cutting goes. You simply change the angle just like going from a left 45 to a right. When cutting upside down you generally set the blade at 90 and the angle at 45. In flat cutting crown you set the blade at 33.9 (for standard 38x52 degree crown) instead of 90 and the angle at 31.6 instead of 45. Once the bevel is set you just swing from 31.6 to 31.6. The extra work comes when you have to make a square cut and have to tip back up to 90. My saw is older and only bevels in one direction, therefore when flat cutting crown, I have to cut one side face up and the other side face down. If the crown is not flat with the face down (most are), I have to build a filler to get it that way.
One drawback to cutting flat with a one-way bevel saw is that the hold down pressure pinches against the blade slightly on the right of the saw. The good part is you get a clean face cut with the face down. If I can fit the crown under my saw upside down, I prefer this way, as I find it easier to see my short point marks and the blade cuts with the face out again giving a clean cut. Also this puts less strain on the blade. When using the upside down cutting method, I build an auxiliary table with a high fence and a bottom table. The kerf through the add-on fence gives me a perfect alignment with where the blade will cut. I brad a stop on the table so that every cut will be indexed the same. I gave up hand holding a long time ago. Some saws are now coming with a table stop. If you do a lot of wide crown, 6"-12", or open stair stringers, a double bevel saw would be nice to have but you don't need one. One thing to keep in mind with crown is that it is usually milled from flat stock and more wood is removed from one side than the other. As with planing, taking more off one side can cause cupping. The angles and bevels may have to be tweaked some to match stock and site conditions.
From contributor G:
Contributor H, I used to use a fixture something like that, too, but learned a silly lesson a few years ago. When cutting on-the-flat, you don't have to turn the molding face down or make a fixture to hold it flat. Just whirly-bird the molding - end for end. Easy-peasy.
The thing to remember when you're cutting on-the-flat and turning the material end-for-end (and I recommend this method even if you have a double bevel saw because the bevel gauges aren't nearly as accurate as miter gauges, so you're introducing error each time you change the bevel angle) - sometimes the bottom of the molding, where the measurement marks are made, is against the fence and sometimes it's away from the fence.. out toward your face and just where you want it so you can line up the blade with the measurement mark. To be sure it's always like that when you're cutting to a measurement mark, always make your first cut with the bottom of the molding against the fence. That means, if you use a cut list, you'll always want to cut your LH inside and RH outside corners first.
From contributor R:
Are you saying that the average non-pro doing home crown jobs does not need a double bevel slider saw?
From contributor G:
Yes. Absolutely. The average homeowner does not need a double-bevel saw for cutting crown molding. They may want one because they're high-tech and sexy, or because they cut boards square like a radial arm saw. But the easiest way to cut crown is in-position, leaned at an angle against the fence and base of the saw, just like it sits on the wall and ceiling except upside down with the base of the saw the ceiling. A DeWalt 12 in. 706 saw will cut 7 in. vertically (baseboard standing up), and will therefore cut 8 in. crown. Homeowners rarely install anything bigger than that. Pros often do, which is why they need slide saws... and for other fun chores, too.