Benchtop Mortising. Acceptable results?

[Greg Peterson]

Chopped/drilled a number of mortises into pine lumber and have some questions about acceptable quality of the cuts.

Along the grain I found making two passes helped to clean up the cut, but still did some light touch up with a chisel afterwards. End grain was fairly rough, as to be expected in such a soft wood.

Just checking to see if there is a fair amount of time spent cleaning up mortises created from the benchtop units.

Thanks.

[Shawn Pixley]

How much care did you take getting the mortiser set up? I first got mine dialed in, but once that was complete, no clean-up is required. Did you sharpen the chisels? Like chisels and plane irons, they work best when extremely sharp and polished.

Pine may be softer and tend to bend rather than cut. I first set up on poplar and the chech on scrap of hardwood i am using.

[Rod Sheridan]

This is what my mortices look like without clean up.


Regards, Ro.

[George Bregar]

This is what my mortices look like without clean up.


Regards, Ro. Bout right. Mine too.

[Neil Brooks]

Mine, three.

And ... absolutely agree that ... if you haven't put the time into prepping your chisels ... you should.

Made a HUGE difference with mine (Grizzly).

[Matt Day]

I sometimes have to clean them up (a few real quick passes with a chisel to take down an edge or something) but that is usually user error. Make sure you don't take too deep a cut with each plunge. For instance, if you have a 1 1/2" deep mortise, rather than making each plunge 1 1/2", split it up into multiple 1/2" or 3/4" plunges. If I go too deep the bit will twist or move a little as it goes deeper - I think because of the grain.

After sharpening/honing, your cuts will be much better as the others have said.

[Brent Ring]

My sides are always just fine, given all the other comments about sharpness. My problem is that I end up making them too shallow and have to clean the bottoms more than anything else. Does everyone else have to clean the bottoms of their mortises as well? I always have some spirals at the bottom that need to be chipped out.

[Rod Sheridan]

Hi Brent, if I have space, I simply make the mortice deeper than required, otherwise it requires cleaning out.

Regards, Rod.

P.S. You always want the mortice deeper than the tenon to prevent hydraulic lock.

[George Bregar]

What Rod said...I always get some scalloping but it doesn't matter.

[Greg Peterson]

Thanks for the picture Rod. I would say that cleanliness of my mortises, given they are being cut into high grade 2x4's, is about right then. The machine is dialed in pretty well. Could probably get the chisels a little sharper, but then again it's almost always possible to get something sharper, at least for me.

I agreed to make this project out of 2x4's at my brothers request. My first venture into mortise and tenon, so I'm learning as I go along. I tried to talk him into using some higher grade wood but he considers a table made of wood crafted from 2x4's an upgrade to what he currently is using in his studio. I didn't protest too much because I figured if I could make a table out of premium grade 2x4's look acceptable, future projects will benefit from the experience.

I'll post pictures when completed.