It is not critical for your mortises for your stretchers in your bench to be a perfect tight fit for the tenons. So don't sweat it if the tenons are not square. If you draw ore the joints you will get a strong, sturdy joint.
Contributor
It is not critical for your mortises for your stretchers in your bench to be a perfect tight fit for the tenons. So don't sweat it if the tenons are not square. If you draw ore the joints you will get a strong, sturdy joint.
[OP]
Member
I'll just say it's a good thing the apron is going to hide my first one. Yikes.
Contributor
Work your way around the table and then re look at the first one. It should be OK, especially if you are drawboring them (good idea) as Joe says. If you are really still unsatisfied with the first one, you can trim the mortise out a little to clean it up and then glue a thin shim on the tennon (on the correct side) and slowly skin the fat side of the tennon down to the correct thickness. That can be done with a chisel, router plane, shoulder plane, flat rasp or saw if you can hold it to the line. Plane shavings (curls) make especially good tennon shims for minor increment changes or you can glue up an over fat shim to the side of the tennon and then recut it with a saw and start all over with that side.
David
Contributor
On big mortises I cut them differently than I cut small mortises. I generally cut mortises right to the line, but large through mortises I often cut in from the line then pare toward it. I Don't leave a lot, just 1/32" or so on either side so that I can tune the fit.
Last edited by Brian Holcombe; 08-13-2017 at 7:03 AM.
Bumbling forward into the unknown.
Contributor
Have tried the bevel chisel routine.....have an 8mm from Aldis.
Biggest thing I do is do the tenons first. then trace around the tenon to mark out the mortise....I try to leave those lines.
Chopping is a matter of tap, move, tap, move. One whack of the mallet/hammer, move the chisel forward a bit, and whack again. After a couple, clear the chips. This will leave room for the bevel to push the chips out of the way. When you get to one end, make sure the chisel stays vertical, no leaning allowed. Do not wiggle the chisel side to side, either. Clear the chips, and repeat....doesn't take all that long. Do a dry fit to check on the fit, and the depth.
Clear chips by laying the bevel down. push the chisel a bit to raise the chips right out. No need to pry.
Member
I don't use Sellars' technique, but it's probably worth noting that he demonstrates chopping mortises with a bench chisel, which is exactly what the OP needs. IMO there are more efficient ways to go about it if you used pigstickers.Originally Posted by Nicholas Lawrence
Contributor
IF you had any, of course....
[OP]
Member
I'm sure I'll end up with mortise chisels eventually, but yeah, for now I just have the bevel edge.
I've got the first four chopped and the tenons cut to fit. Certainly not perfect, but number four is markedly better than the first one was.
I guess the good news is my sawing is better than my chopping. Really liking these Japanese saws.
Member
It's a surprisingly fast learning curve to get to where you can produce perfectly usable results. What isn't so easy to develop is speed. People who've been doing it for a very long time can bash out a good mortise in a minute or so, where it would take somebody like me significantly longer.
The Sellars video is here. It's important to keep in mind that the "end-in" technique he uses is reasonable for a bench chisel, but IMO not optimal for a pigsticker. His failure to adapt his technique to each type of chisel is probably why he finds the bench chisel to be faster :-).
Last edited by Patrick Chase; 08-13-2017 at 6:40 PM.
Member
It should also be noted that because the plastic guard worked as a guide for placing the chisel, Paul could chop and pry out the waste relatively quicker. Without the guard, he would have spent a bit more time each time he raised the chisel and re-placed it on the mortise.
I have seen his perfectly clean mortise & tenon work and so I am sure he did the video in a less careful way just for demo purposes, because I don't like the way he pried the last bits of bottom waste with the mortise chisel, bruising the ends of the finished lip. In other clips, he was a lot more careful in the prying.
Simon
Last edited by Simon MacGowen; 08-13-2017 at 7:43 PM.
Member
Even if you could get the bottom perfectly "clean" it wouldn't matter, because the glue joint between it and the end of the tenon is end-to-long grain and therefore quite weak. Basically all of the strength of an M&T comes from the long-to-long grain interfaces between the cheeks.
To be clear, I have no concerns about the mortises Sellars produced in that video. My critique was that the pigsticker would have been faster if he'd taken the time to optimize his technique for it.
Member
I mean clean lips, not the bottom.
Member
Maybe he was going to put tiny matching haunches on the tenon :-)
Seriously, most of the time the end lips don't impact structural integrity either, though obviously they will if they meet a shoulder-less tenon face. I've seen people with far more skill than I rapidly bash out mortises with rather ugly ends and bottoms, but immaculate cheeks. IMO they're onto something :-).
[OP]
Member
Taking smaller bites and paying closer attention to chip removal helped a lot on this last one. They seem to be getting incrementally better, although I'm painfully slow and working on sawhorses is killing my back.
5 down, 3 to go.
Member
Both the bevelled edges of your chisel and the secondary bevel on the edge make for instability and sloppy mortises. You can make mortises with a chisel like yours, but it isn't as easy. In the long run you will want a mortise gauge, set to the width of the chisel and used to mark both timbers, and a mortise chisel with a flat bevel.
Since you are working on saw horses, I recommend sitting on the piece you are mortising. This will keep the piece steadier and be better for your back.
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