Been reading books on Shaker furniture, and there is common statement that cabinet door frames often had through mortise and tenon joints. Craftsmanship was very important to the Shakers so it seems likely the exposed mortise and tenon fit together neatly without tearout.
The Shakers apparently used mortising machines, perhaps even invented them. I have a Powermatic 721 (I think) mortiser with which I often use Delta 1/4 and 3/8″ chisel and bit sets. The bit always seems to drill a slightly larger diameter hole than the width of the chisel, so a through mortise wouldn’t be that neat and crisp.
A mortising chisel and some practice should yield very neat and crisp through mortises, but will add to project time and not sure customers will be willing to pay for extra time.
Will better made mortising chisel and bit sets make holes without rounded sides? If so, willing to recommend any manufacturers? Thanks.
Replies
The only way that can happen is if you have the bit projecting too far out the end of the chisel and the quill has runout. The wobbling bit will cut a hole too big for the chisel to come along and square up completely.
Edited 12/14/2009 8:25 am ET by Marsupial
Don, I don't know how you could get a bigger hole with the drill bit than the chisel unless something is awry.
I will say this. There's a big difference in quality in mortising machine bit sets; actually in the machines, too. Some are rickety.
But with a decent machine and bit, and with clamping your piece to the fence, you can get perfect mortises. I know this is tedious, but for the exposed through mortises, it may be your best alternative.
Denny
Perfect fitting through mortises are not the easiest thing to accomplish. I agree with denny about the quality of the machines and bit sets. Unless you are willing to spend 1000's on a mortising machine, you will need to do some clean-up by hand, but I find it enjoyable to put a freshly honed chisel to work. Also, if customers want a handcrafted, heirloom quality, piece of furniture, they should realize that it will cost more than the import junk that feature fake, tacked on, through mortise and tenons.
I have an "ikea" - why not do regular stopped tenons, and then inlay a stub of end grain on the outside edge of the stiles? ;-)
I have had the very same thing happen to me. It was the result of less than top shelf chisel & bit sets. I was able to solve the problem by putting the chisel set in the mortiser Running it and holding a diamond hone flat against the side of the tip of the chisel. The turning bit was ground down flush to the outside of the chisel. It was a way to salvage a cheap chisel set, but next time I will buy better chisels.
Don , I have been using the 719 (I think) for quite some time now along with the bits that were supplied with the machine, essentialy the same machine with no tilt function. Sounds to me like some new bits are in order. I do not know the brand of bits that came with my machine, I do know they have performed flawlessly. As for through mortises try setting the depth of the mortise a little more than half way and flip the piece over and finish mortise.
Edit, stock must be square.
I have used this method many times with good results
Tom.
I've been using a couple (US)
I've been using a couple (US) nickels (about .074") to set the gap between bottom of chisel and bit, and saw suggestion somewhere to use a (US) dime. I'll try to give that a try tomorrow and reply with results.
Don,
Try this to set the
Don,
Try this to set the bushing to the chisel. When the set screw for the bushing is loose you will notice that there is some up and down play in the bushing due to the fact that the set screw hole in the bushing is largerthan the set screw. Loosen the bit and the chisel, pull the bushing down and lightly tighten it. push the bit up to the chisel till it stops and tighten. Now loosen the bushing and push it up using the play in around the set screw, now tighten. The distance between the chisel an bit should be correct now.
Tom
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