Re: Getting rolling - dadoes, mortises and tenons
Posted: Fri Feb 24, 2012 5:56 pm
Continuing on now with the work on the internal partition joinery.
On my box, the top of the tenon is located 3/16" below the top of the dado. To mark out of the mortise inside the dado, I take a pair of gauge blocks and stack them vertically at the end. Then I push down with a chisel to define the top of the mortise:
The tenons on the partitions I have set at 1" in height. I therefore add 1 more inch of gauging blocks to the pair already in place, then lay a gauging block into the dado and press the whole shebang tight:
Then with the horizontal gauge block clamped in place, I pull out the vertical stack of gauge blocks and make a second chisel mark to define the bottom of the mortise:
The sidelines of the mortise are 1/16" (1mm) in from the dado side walls, so I use a 1/16" gauge block to guide a marking knife along. The result:
If you notice there are two upper lines knifed in - I had made an error with the spacing of the first mark, so I'm glad I double-checked before moving into cut out.
Speaking of cut out, these mortises are in the middle of the panel so my hollow chisel mortiser can't quite get to them. Over to the drill press then:
Then some freehand chisel paring work:
Once the mortise was cleaned up, I went and grabbed the 1:8 paring jig. In this case, the depth is actually 0.375" not 0.5". I could have recalculated and made another jig for a slope of 1/16" over a run of 0.375" (a 1:6 ratio), however I chose instead to just make one type of tapered wedge and in order to use a 1:8 paring jig in this case, all i had to do was move it slightly inboard of the line. I just did this offset by eye, however I use a square to make sure the edge of the jig is square to the board:
Then I pared away the tapered mortise wall:
This one is done, save for final fitting -see how the pared wall is slightly in from the marked line?:
Some things I fuss more than others. I'm less concerned with very tiny differences in how the trimmed wedges may look on the surface of the board than i am about getting a good mechanical joint. If the difference was more pronounced, I would have made a separate paring jig.
Then i used a combination of router and table saw to process the tenons and so forth on the ends of the partitions:
Finally, I decided to try a partial assembly to take a gander at how things were shaping up:
For more on the trial fit and consequences, take a look at the thread 'Preliminaries: What Goes in the Box' where I'll delve in a little further...
On my box, the top of the tenon is located 3/16" below the top of the dado. To mark out of the mortise inside the dado, I take a pair of gauge blocks and stack them vertically at the end. Then I push down with a chisel to define the top of the mortise:
The tenons on the partitions I have set at 1" in height. I therefore add 1 more inch of gauging blocks to the pair already in place, then lay a gauging block into the dado and press the whole shebang tight:
Then with the horizontal gauge block clamped in place, I pull out the vertical stack of gauge blocks and make a second chisel mark to define the bottom of the mortise:
The sidelines of the mortise are 1/16" (1mm) in from the dado side walls, so I use a 1/16" gauge block to guide a marking knife along. The result:
If you notice there are two upper lines knifed in - I had made an error with the spacing of the first mark, so I'm glad I double-checked before moving into cut out.
Speaking of cut out, these mortises are in the middle of the panel so my hollow chisel mortiser can't quite get to them. Over to the drill press then:
Then some freehand chisel paring work:
Once the mortise was cleaned up, I went and grabbed the 1:8 paring jig. In this case, the depth is actually 0.375" not 0.5". I could have recalculated and made another jig for a slope of 1/16" over a run of 0.375" (a 1:6 ratio), however I chose instead to just make one type of tapered wedge and in order to use a 1:8 paring jig in this case, all i had to do was move it slightly inboard of the line. I just did this offset by eye, however I use a square to make sure the edge of the jig is square to the board:
Then I pared away the tapered mortise wall:
This one is done, save for final fitting -see how the pared wall is slightly in from the marked line?:
Some things I fuss more than others. I'm less concerned with very tiny differences in how the trimmed wedges may look on the surface of the board than i am about getting a good mechanical joint. If the difference was more pronounced, I would have made a separate paring jig.
Then i used a combination of router and table saw to process the tenons and so forth on the ends of the partitions:
Finally, I decided to try a partial assembly to take a gander at how things were shaping up:
For more on the trial fit and consequences, take a look at the thread 'Preliminaries: What Goes in the Box' where I'll delve in a little further...