miter saw angle for outside corner molding?

Patti Pittman

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6
Hi,

I need help figuring out the correct angle to cut outside corner molding when installing it around a hall entrance. The corner molding is 90 degrees (to cover up where the wall corner meets, looks like this: http://mouldinginstallation.com/how-to-remove-corner-molding/corner-molding-0-jpg/), and I'd like to do one side, and the top of the hall entry. Flawed thinking...cutting at a 45 degree angle, like when making window frames, does not work. I do not think this would be a compound cut, but the angle has me perplexed, being two-sided.

Thanks for suggestions.
-Patti
 
if i understand you correctly you are trimming out a alcove in the entry way so you would cut a normal 45 just need to position the trim in respect to where its going patti,, take a small piece and try it till you can see the picture your after.. oh and welcome to our forum, we are a united group of some great talent:)
 
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A 45 degree cut would work fine, if you lay the trim flat. But, covering 2 walls with the 90 degree corner trim throws off the angle.
 
Well its 1/2 the angle of the corner... whatever that is. I believe, based on the description, what you're finding is that the corner is not in fact 90 degrees but some ~not quite but almost 90 degree angle. This is fairly common when doing trim work (at least it was in my house :rolleyes:) so you have to figure the angle and then bisect it.

Doing one side at 45 and then matching the other will "work" but tends to leave the side with the longer angle proud a little (ok if its paint grade, just bevel it, caulk it, paint it and call it a day), not so happy if its stain grade.

The easiest way is to use something like this: http://www.leevalley.com/US/wood/page.aspx?p=48337&cat=1,43513
Worth the $20 if you're doing a lot of trim and aren't really good at eyeballing it/fitting to match.

More generally useful is something like this (there a myriad of variations, this is not what I have, I have something almost but not quite the same I picked up at an estate sale for $1): http://www.amazon.com/Starrett-505P-7-Miter-Saw-Protractor/dp/B003CJSQ4S/
Where you can measure the outside angle and then divide it in half to get the correct angle

Round corners are more interesting, I had a lot of those when I redid the trim in my current house. They look best (to me) with 2 small blocks between the long trim pieces to compound the curve. The angle to cut is the all angle divided by the number of cut sides so in this case we have the 2 long trim pieces and 2 short trim pieces to go around the corner so its "90" divided by 6 (=====s1 2s3 4s5 6s=====) or 15 degrees. I cut a whole little box of the short pieces (about 1/4" wide at the back/narrow part) and just fit them as the went in place on each corner as every corner was slightly different.

A decent book that got me through our house is: http://www.amazon.com/Tauntons-Trim-Complete-Expert-Advice/dp/B002B55XIG
I'm not claiming there aren't better ones, just that that one was good enough to get me by :D

http://www.amazon.com/Tauntons-Trim-Complete-Expert-Advice/dp/B002B55XIG
 
HPIM0222.jpg

If the attachment works out, here's a photo of the hall. I suppose I could chop at random, since I messed up the trim on the first try by getting the cut wrong...I can tell you that a 45 degree cut on 90 degree corner molding will leave a big gap on both sides of the cut.
 
What I want to do is trim out the left side and top of the hall, using 90 degree corner molding. I need to use corner molding to cover the gap, which is not consistent, on the left side of the hall.
 
If I'm seeing your photo correctly, you're using crown molding. The best way to cut crown is to place it upside down on your miter saw; i.e., the top of the crown on the table of the saw and the bottom on the saw fence. Leave the saw blade 90° to the table. Set the miter saw angle to half of the angle of your corner; i.e., 45° for a 90° corner. This works whether it's an inside or outside corner; saw blade moved left for inside corner or right for outside corner.
 
If I'm seeing your photo correctly, you're using crown molding. The best way to cut crown is to place it upside down on your miter saw; i.e., the top of the crown on the table of the saw and the bottom on the saw fence. Leave the saw blade 90° to the table. Set the miter saw angle to half of the angle of your corner; i.e., 45° for a 90° corner. This works whether it's an inside or outside corner; saw blade moved left for inside corner or right for outside corner.

bill she is using normal outside corner wood trim,, not crown molding.. i have done what your trying to do with 45 degree cut take a piece and cut it with a support block under it to get the 45 to carry threw correctly.. there maybe a out of square corner your dealing with which leads you to have more troubles with this.. just use a scrap piece pattie,, maybe someone could make a quick sketch up pic for you to see what i am trying to say:)
 
bill she is using normal outside corner wood trim,, not crown molding.. ... ..maybe someone could make a quick sketch up pic for you to see what i am trying to say:)

Oops...I shoulda read more carefully - me and my one and a half eye! In the photo, it looks like crown is being added at the top of the wall and intersects an odd angle.

Someone??? SketchUp pic? You sound like a good candidate! :thumb:
 
a sketch would be great! Yes, I'm using normal outside corner wood trim. Another visual, http://www.woodworkersshoppe.com/Knotty_Pine_Paneling copy.jpg (this is not my house! Darn!) Anyway, to the right of the vent, you'll see how they intersect the trim. Doesn't it look like it's 45 degrees where it meets, on both sides?

side note, I was able to reuse all of the crown after I installed the pine plank paneling, so one less thing to learn about.

another side note...must have root canal, it may be a bit before I can respond again. Many thanks!
 
patti not to sound like a brokern record but that last pic is trim cut at 45 degrees, hopefully bill could draw up something for you as i am not up to it right now bill... and by doing so it could be blown up big so you can see what is going one.. also look up cutting outside corner trim methods for some info on you tube perhaps and maybe a pdf of a article on it..
 
OK, unless I'm totally messed up again, here's they way I'd do outside corner molding:

Cut a backer block to the angle (45° here).

CornerMold0.jpg

Rest the workpiece on the backer block and make your cut.

CornerMold1.jpg

This should work for any cut close to 45°.
 
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I did it! After looking at Bill's visual, I see that you cannot clamp the corner trim, pointy side up, and expect to get a 45 degree angle on the cut (which is what I had done). Angle matters. I clamped the trim as shown in Bill's photo, and by golly it worked like a charm! I gloated the rest of yesterday afternoon, so happy with my accomplishment. A BIG THANK you to everybody for helping me figure this out!
 
Kinda late on this post & I haven't made many molding cuts, but whenever I did, I found that by setting up the molding in the miter saw the same way as the molding would be used & cutting it in this position it would result in the cut I was looking for. Bill's pictures presents this perfectly.
 
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