Hollow Mortise Chisels

[Ruffnek]

I got a set of Imperial Hollow Mortise Chisels and bits from Lee valley a few weeks ago to replace the ones that came with my Delta benchtop mortiser, model 14-651.

Those Delta mortise chisels worked...after a fashion. The biggest problem with them was clearing the chips, plus they didn't cut all that well even new. (anybody want a set of used Delta Mortise chisels and bits...minus the 1/4" (the chisel bent and the bit broke).

I got the Imperial set (Japanese) based on a review by Terry Hatfield over at SMC and I am very pleased with them. For the past two days, I've been cutting mortises to build a plant hanger for Karen's "Topsy-Turvy" tomato planter and a small table I am making for my boss. The chisels cut through the PT Pine and the Soft Maple like butter. I've had absolutely no problems with chip ejection. This was with the 1/2" chisel and bit.

The only minor issue is that the bit shanks are too long for my mortiser. I had to hacksaw about 1" off of the shank...no problem...and it worked great. I use a nickel to adjust the bit-to-chisel distance. I also bought a set of cone-shaped hones but haven't had to use them yet.

[sawduster]

I also bought a set of cone-shaped hones but haven't had to use them yet.

Eventually you will and be glad you got them. Sounds like a good buy.

[dcarter636]

What a coincidence, we stopped by our local Woodcraft to get a 1/2" hollow chisel bit last evening. I was adequately impressed with their Chinese no-name 1/4" bit that I figured I'd try another one for the crib leg mortises.

Those fine diamond cone hones make a clear positive difference in my experience. I hand hold and oscilate them cw-ccw a few dozen times to see a much finer and more durable edge on the hollow chisel.

What do you do with the nickel?

[sawduster]

I believe he's using a nickel to set the space between when the bit starts cutting and when the chisel makes contact with the wood. I've always used a dime.

[rrich]

I use a dime rather than a nickle.

The trick is to set the auger part of the set to be a dime thickness below the hollow chisel.

Reduces burn out and makes cutting the mortise smoother and easier.

[brburns]

I use a shim, but it's close to a dime thickness (maybe just under). I have the Deta chisles that come with the DP mortising and was not impressed with them. I have since cleaned them up, removed most of the tool marks on the sides of them and used the cone shaped hone to sharpen them. It helped allot, but still not great.