Crown molding material

[Ben Hatcher]

I'm putting up painted crown molding in my bedroom. There are lots of angles. The doorway is at a 45 to the room and both windows jut out into the room. I'm trying to choose between primed MDF and unfinished poplar. They're both about the same price. Which would you choose?

I'm leaning towards the mdf as I'm told that it is pretty stable and I can simply miter the corners whereas I'd need to cope the poplar.

[Rich Capizzano]

I would definitely go with the MDF, mush easier to work with, finished product looks very nice.

[Prashun Patel]

MDF all the way. Those compound angles'll miter nice and smooth. It's bendy so it will conform to yr walls and ceilings, and it's way up on the ceiling, so you won't notice that mdf profiles tend to be less 'sharp' than wood. It's also usually smoother than wood molding out of the box, so you won't have to prepsand or prime it. You can go straight to the topcoat.

[Josiah Bartlett]

I'll buck the trend and say to go with poplar. It doesn't get fuzzy edges when you cut it, it doesn't droop, doesn't dull your saw blades, and it looks like there is wood under the paint. Even though mdf is fairly dimensionally stable, that doesn't mean your wall is. Always cope, its not hard and it looks much better.

[bill mullin]

I would use the poplar. The only advantage I see with the MDF is one less coat of paint and sanding. If this is important to you, use the MDF.

I don't understand the statement about coping poplar, and not coping MDF. They are cut and installed exactly the same. One thing about MDF, is that it is very easy to chip the coped ends as you are fitting them.
Also, if you are installing yourself, poplar is much easier, as it is stiffer and easier to handle.

[Kyle Iwamoto]

I'd go with wood and a clear poly. I like the look of wood.

Just my $0.02.

[John Keeton]

Another vote for poplar - a better look of quality. If cost is the same, and labor the same, the overall value added will be better with poplar IMO. And, I would cope the inside joints in either event.

[Prashun Patel]

In theory, since mdf does not shrink and contract like wood does, gaps won't open up in the corners, which reduces the need to cope. In practice, I can vouch that both wood and MDF can show gaps over time.

In theory, mdf will chip easier when coping and fitting. I can tell you that I used mdf crown for my entire house. I coped every joint and chipping was not an issue.

In theory it can dull your blades too, but I'm still rocking an Irwin marathon blade on my miter saw that's about 7 years old and has seen countless linear feet of mdf. It doesn't dull as quick as one would think.

Coping is so much easier on mdf than wood - especially if you use rasps and files to perfect the profiles.

[Paul Greathouse]

Ben, assuming you don't already know how to cope, no matter what material you choose, do yourself a huge favor and learn how to cut copes. Hardly no corner is perfect and coping takes care of angle imperfections. Its not really as hard as it appears. Do some searching on the internet for coping instructions if there is no one locally you can learn from.

[Don Morris]

I've done both but don't like cutting MDF. Don't like MDF dust. Personal choice. On baseboards if it ever gets wet, that can be a bummer. Poplar is my choice. The comments about learning how to use a coping saw are correct. Not too difficult. Also, get a good coping saw. I just had to replace mine (real old and a part broke) and didn't realize how a good rigid one was a nice help. My previous one was a little flexible and I didn't realize that caused me some difficulty in touchy parts of the cut. There are some exotic mechanical systems out there, but a good coping saw for $15.00 and a little caulk for wild corners/ceilings and walls will accomplish the job pretty well.

[Bill Orbine]

For overall quality of moldings, I prefer wood over MDF. I've worked with both and I have little trouble with the mitres, copes and installation or either material. I feel wood give me better quality as it looks "straighter" because it's stiffness doesn't bend so easily on distorted walls and ceilings. MDF bends so easilys and tends to highlight the distortion in the walls and the ceiling and therfore you can easily see the wavy patterns making MDF moldings appear like crappy work. As for gaps, especially with wood..... allow the material to acclimate to room for a couple days, if posssible before caulking and paint. And I have good results with "Big Stretch" caulking for paint grade materials on either MDF or wood rather than Alex which seems to harden up too much and not be so pliable.

[Dave Schreib]

I Am in the middle of this projtect today. I am using pre-primed pine from HD because it matches what is in the rest of the house.

This is the first time I have done crown molding and I did no research on the project and didnt even search here before I started. I tried cutting exact miters for the inside corners and that worked fine for the first corner (2 pieces of trim) but when I got to the next corner, getting a decent fit was literally impossible. The wall is off a little, the ceiling is off a little, the trim is off a little, my layout was off a little. Put it all together and getting an acceptable inside miter was impossible.

Only after several hours of frustration and then removing those first two pieces of trim did it occur to me to examine what the trim carpenter had done in the kitchen (about 6 inches from where I was working in the mudroom) and I realized that he had butted one end and coped the other. So I went out and bought a coping saw for $7 and after doing 2-3 I am find the copes very easy. Now I am cruising along.

Except I have to go back to HD to buy more crown to replace the roughly 30 ft that I screwed up. My advice is to buy more crown than you think you need because you will cut the wrong end or have the wrong edge against the fence or cut it at the wrong angle or just plain measure wrong. I have an assortment of 5-6 ft long pieces of crown that are unusuable because I made one (or more than one) of those mistakes. Good luck.

[Larry Edgerton]

I've never seen a house advertized as having "Real MDF moldings".......;)

[Ben Hatcher]

Thanks all for the great advise. I kind of figured that I'd get about the same amount of responses on either side.

Yes, my initial reason for MDF was that since it "doesn't shrink", coping wouldn't be needed to hide the gaps caused by shrinkage. Shawn good to know that even MDF shrinks.

I know how to cope, or at least I used to. I recall it being a pain in the neck, time consuming, and didn't really give a superior joint. I found I could get a pretty tight joint with a miter as long as I cut the angle of the wall and not just a 45 every time.

Anyway, over the weekend I found a great deal on some poplar molding, so even though I'd rather use MDF, the deal will end up breaking the tie.

[Dave Schreib]

I've never seen a house advertized as having "Real MDF moldings".......;)

My ad will say "real caulk and putty molding with a little bit of pine."

[Jim Rimmer]

I have an assortment of 5-6 ft long pieces of crown that are unusuable because I made one (or more than one) of those mistakes. Good luck.
I have made shelves for LOML with a 1x4 on the back and 1x6 as the shelf and then put crown mold underneath. Good use for those short pieces. I routed an angled plate groove in one shelf. I have made 3 or 4 of different lengths and have requests from relatives for more.

[John M Wilson]

This is probably old news to the skilled professionals installing crown, but for a newbie like me, it saved me a ton of improper cuts. One of the on-line tips I read before doing an install job on my brother's house was to cut 4 small pieces of crown as an example: inside left, inside right, outside left, and outside right. Label these small examples, and carry them with you when you are measuring the pieces for the wall. When you get back to the saw, you can tell right away if you have your miter set properly, and the stock on the correct side of the blade. Just passing it along...

[Ben Hatcher]

My ad will say "real caulk and putty molding with a little bit of pine."

Isn't wood just a cheaper alternative to plaster?

All you'll see of the finished product is the paint. To me, it doesn't really matter what's behind the paint as long as it holds it in the right shape.

[Dave Schreib]

I have made shelves for LOML with a 1x4 on the back and 1x6 as the shelf and then put crown mold underneath. Good use for those short pieces. I routed an angled plate groove in one shelf. I have made 3 or 4 of different lengths and have requests from relatives for more.

that's a good idea. Thanks