# Help with stair trim



## Dankristen01 (Aug 23, 2020)

Hi all, new to this forum and look forward to learning alot. I need help with cutting trim that goes along my stair stringers. I took pictures of where I tore the old stuff off, I'd like to replace it with quarter round and can't for the life of me figure out or understand how to cut the appropriate angles. Any advice / help would be greatly appreciated. I do have a miter saw and have plenty of experience doing regular baseboards, this trim just has my mind boggled. 

Dan


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## BigJim (Sep 2, 2008)

Lay a piece of trim on the skirt and mark the top on the wall out past the angle of the skirt. Now lay that piece of trim on the other plane of the skirt angle and mark the top of the trim on the wall at the angle.

See where the top intersects at the angle of the trim on the wall? You want to lay a scrap piece of flat scrap the same width as the trim piece on the skirt, let it go out past the intersecting angle point. See where the two lines on the wall intersect at the angle. Make a dot on the top of your flat piece where the two lines on the wall intersect, now before you move the trim piece, make a mark on the bottom of the flat piece at the intersection point of the skirt. 

Flip your flat piece over and draw a line from dot to dot and that is your angle. Go to the miter saw and cut along that line. See what the angle is on your saw. Flip the flat piece over and lay it on your saw as that will be the way your actual trim will lay to be cut. 

See how you will need to cut in the other direction as you just cut the back of the flat piece. Do the other pieces the same way but they may be a different angle so cut the flat pieces and dry fit them to see if you need to adjust the cut a little.


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## woodnthings (Jan 24, 2009)

*Jim, I can't follow your post but .....*

Am correct that "bisecting" the angle is what's needed to create equal angles? I do know that if you cut a different angle on either piece, the cut length will be slightly different and they won't mate exactly. 

Maybe that's what you were saying in the post, I donno? Maybe it was an on-site method without using any measuring devices like a protractor or angle gauge?


Help me understand if you would? Thanks. :vs_cool:


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## BigJim (Sep 2, 2008)

woodnthings said:


> Am correct that "bisecting" the angle is what's needed to create equal angles? I do know that if you cut a different angle on either piece, the cut length will be slightly different and they won't mate exactly.
> 
> Maybe that's what you were saying in the post, I donno? Maybe it was an on-site method without using any measuring devices like a protractor or angle gauge?
> 
> ...


Bill you are right, two different angles will make one angle longer. What I was saying was not really clear enough. When cutting that angle sometimes it can be off just a hair, so you sometimes have to shave a little off one or the other to make a totally tight joint. 

I never used angle finders when trimming, I just marked the two points at the intersections and connected the dots. 

You can even connect a 2X4 to a 2X6 or what ever using that same method on an angle, just make a mark at the intersections and connect the dots, they will match up, but connecting the 2x4 to the 2x6 the angles will be different lengths. I hope I am not making this more confusing.

Example: 2x4 and 2x6 on a 90 degree run, the cut will not be 45 degrees.


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## _Ogre (Feb 1, 2013)

a 99¢ protractor and a ruler or straight edge will do that
the angle read off the protractor, 50°, needs to be subtracted from 180°
in this case 180°-50°=130° is the angle of the skirt board, 
half of that 65° is what you need to cut you quarter round


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## woodnthings (Jan 24, 2009)

*OK then, throw in different widtth boards ....*



BigJim said:


> Bill you are right, two different angles will make one angle longer. What I was saying was not really clear enough. When cutting that angle sometimes it can be off just a hair, so you sometimes have to shave a little off one or the other to make a totally tight joint.
> 
> I never used angle finders when trimming, I just marked the two points at the intersections and connected the dots.
> 
> ...



Just as I thought, a quick and dirty method for on site trim, no gauges or protractors. I knew it!
:wink:


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## Dankristen01 (Aug 23, 2020)

Thx guys, much appreciated!


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## DrRobert (Apr 27, 2015)

A Starrett miter saw protractor is nice b/c it gives you the actual angle to set the miter saw at - no math.


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## woodnthings (Jan 24, 2009)

*Like these on Ebay ....*



DrRobert said:


> A Starrett miter saw protractor is nice b/c it gives you the actual angle to set the miter saw at - no math.



The one shown is likely a clone of the Starrett:
https://www.ebay.com/itm/Replaces-f...001739?hash=item48e7680ecb:g:OOAAAOSwgaxcoYWm



This is the real one:
https://www.ebay.com/itm/Starrett-ProSite-Miter-Saw-Protractor-505P-7/174398826923?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D225086%26meid%3D3927a87e951c40e48f6dd84545cec1ea%26pid%3D100005%26rk%3D2%26rkt%3D12%26mehot%3Dpf%26sd%3D313120001739%26itm%3D174398826923%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV2bDemotion%26brand%3DStarrett&_trksid=p2047675.c100005.m1851


I have both and they're virtually identical. :|


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