How I get square mitered corners....usually
Posted: Wed Dec 07, 2011 11:47 am
Here's a collection of basic frames I've built over the last 6 or 7 years to display our travel photos at home. All of these, with one exception are what I call gallery frames....kind of a reversed shadow box type construction. While not every corner is perfect.......
All of the prints in these are 8x10s (kinda give an idea of overall size)
[ATTACH]15083[/ATTACH]
The center one is a 16x20 print
[ATTACH]15082[/ATTACH]
This is a more 'traditional' frame with outside dimensions of about 33x43"
[ATTACH]15081[/ATTACH]
Here is my collection of critical frame building tools. The MOST important tool of the bunch is my ancient Starrett combination square.
[ATTACH]15080[/ATTACH]
I guess the length stop on the far end of my miter saw would have to rank right up there with the Starrett. If the opposing pieces ain't IDENTICAL lenghts....it ain't gonna be square. Not shown is my 510 with the jointer attached to get the straight edges required, and my lunchbox planer to get all the stock to the same thickness.
One thing I've learned about getting identical lengths using the stop is to try to use the same force on each piece when butting the first mitered end against the stop. The softer the wood, the easier it is to smush the soft point of the outside edge and get a longer piece. I'll also do a test frame from scrap stock as described by pennview:
The band clamp is also a wonderful invention. I make sure I use the corner supports to keep from smushing the outside corners and try to not over tighten to avoid springing the frame pieces out of square. Another thing to check after tightening the band clamp is to make sure all sides of the frame are flat on the bench surface.
I used my Porter Cable biscuit joiner with #20 biscuits on each corner of the frame in the last picture I posted. This should help to prevent corners from gapping over the long run. The glass made this sucker pretty darned heavy, and a glue-only joint is not the strongest joint in the world as a mitered corner is mostly end grain to end grain.
For me, set up is the most critical step in the whole process. Using the miter saw works best for me, but the same concepts will apply using whatever version of a miter gauge on a table saw, a radial arm saw, or a miter box with a back saw......I've used em all thru the years.
One other thing I might mention is that I also try to assemble my frames as soon as I can after cutting the last corner. Even a slight change in humidity can make some of the pieces crawl around a bit....don't care how dry the wood is....and even a tiny bit can screw up the fit of the corners.
One more 'one other thing'...... If you mount glass in the frame, make sure there is a slight gap between the glass and the frame....exactly like doing raised panels. Let the wood do it's changes with temperature and humidity without putting anything in a bind.
All of the prints in these are 8x10s (kinda give an idea of overall size)
[ATTACH]15083[/ATTACH]
The center one is a 16x20 print
[ATTACH]15082[/ATTACH]
This is a more 'traditional' frame with outside dimensions of about 33x43"
[ATTACH]15081[/ATTACH]
Here is my collection of critical frame building tools. The MOST important tool of the bunch is my ancient Starrett combination square.
[ATTACH]15080[/ATTACH]
I guess the length stop on the far end of my miter saw would have to rank right up there with the Starrett. If the opposing pieces ain't IDENTICAL lenghts....it ain't gonna be square. Not shown is my 510 with the jointer attached to get the straight edges required, and my lunchbox planer to get all the stock to the same thickness.
One thing I've learned about getting identical lengths using the stop is to try to use the same force on each piece when butting the first mitered end against the stop. The softer the wood, the easier it is to smush the soft point of the outside edge and get a longer piece. I'll also do a test frame from scrap stock as described by pennview:
pennview wrote:.... I use a scrap frame and make test cuts until the angle is exactly 45 degrees. This means trimming the end of each piece in the frame for a total of eight cuts. If the angle isn't right, tweak the miter gauge and then make eight additional cuts until the angle is perfect.
The band clamp is also a wonderful invention. I make sure I use the corner supports to keep from smushing the outside corners and try to not over tighten to avoid springing the frame pieces out of square. Another thing to check after tightening the band clamp is to make sure all sides of the frame are flat on the bench surface.
I used my Porter Cable biscuit joiner with #20 biscuits on each corner of the frame in the last picture I posted. This should help to prevent corners from gapping over the long run. The glass made this sucker pretty darned heavy, and a glue-only joint is not the strongest joint in the world as a mitered corner is mostly end grain to end grain.
For me, set up is the most critical step in the whole process. Using the miter saw works best for me, but the same concepts will apply using whatever version of a miter gauge on a table saw, a radial arm saw, or a miter box with a back saw......I've used em all thru the years.
One other thing I might mention is that I also try to assemble my frames as soon as I can after cutting the last corner. Even a slight change in humidity can make some of the pieces crawl around a bit....don't care how dry the wood is....and even a tiny bit can screw up the fit of the corners.
One more 'one other thing'...... If you mount glass in the frame, make sure there is a slight gap between the glass and the frame....exactly like doing raised panels. Let the wood do it's changes with temperature and humidity without putting anything in a bind.