Paul Sellers
Established Member
Hi Pam,pam niedermayer":130hu6xa said:Tony":130hu6xa said:Which other tools?
Why is it not a good idea?
Why do yo think the mortise chosel geometry is the way it is? To lever out the waste
There are the swan neck tools designed for levering out chunks of wood, sculpting the bottom. There are also 3 Japanese tools that you can see at the Hida site. Go to http://www.hidatool.com/shop/shop.html and choose Woodworking Chisels, scroll down about 1/3 of the page to the Takahashi and Fujihiro cleanup chisels.
It's not a good idea, except for the oval handled bolster version, for exactly the reason for this thread. With socketed handles, they can break. Also, you put great pressure on the edge (the oval handled bolsters I've seen have sort of rounded edges that are strong). With Japanese chisels it's simply the best way to trash edges.
Which mortise chisels geometry are you talking about? The trapezoid shape is, I think, more to cleanly cut the mortise without having the sides get in the way. The arrises on Japanese chisels are very sharp, cut like a dream. I once had several square mortise chisels that did a great job of splitting the wood.
Pam
You are right about swan neck chisels being used to clear out the bottom of mortises, but swan neck chisels were used for the very deep mortises associated with the installation of mortise locks after face or rim locks became obsolete. I am sure some used them for levering regular mortises but in reality the whole system of mortising is a series of actions whereby the person strikes the mortise chisel in it's perpendicular position to the wood and then immediately levers in quick succession with the same chisel as he or she traverses the mortise hole from one side to the other, which actually deepens with each subsequent mallet-lever, mallet-lever action until the mortise is rough-cut. He then turns the chisel around and repeats the same mallet-levering action in the opposite direction which actually levels the depth of the hole. It's not scientific at all. Swan neck chisels were not generally available in all width sizes and actually the most common sizes were between 1/2" and 5/8" which was fine if the holes were bigger but useless of course if smaller.
Also, it is not normal for any chisel handle to break. I think that this incident was an exception and not the norm. I cannot ever remember breaking a chisel handle in forty three years of working with wood every single day. Socketed chisels are no more likely to break than any other and I would also add that sensitivity doesn't happen by accident, you have to cultivate it. It may well have been some other failure rather than design. Most people, no matter what they are doing, lever with chisels, chisels of every different kind.
Paul Sellers