This is not a dovetail, so what in the world do you call this?

[Bill Baethke]

I ran across this interesting drawer joinery that is new to me. The seller claims this is from a turn of the century captains desk. Does anyone know about this joint?

[Derek Cohen]

Those are pin and cove dovetails, or the Knapp Joint. They were patented by Charles Knapp in 1867, and the first known machine made drawers.

Regards from Perth

Derek

[Bill Baethke]

Thanks, Derek. I guess this doesn't belong in the Neanderthal forum then. I assumed since it was pre 1900 it had to be hand tooled, but I couldn't figure out how it was made. I thought maybe it was designed to combat humid conditions on a ship. I appreciate your answer.

[Rick Malakoff]

A little more information here.

http://www.antiquetrader.com/antique...ovetail_joints

[george wilson]

I know a guy who,as a joke,makes accurate as can be infill planes with those joints holding the steel bottoms onto the brass sides ! I mean,it is NICE WORK,TOO!!!!

Personally,the first time I ever saw those joints,I thought they were ugly,somehow. I was 18 at the time,so I MUST have made the correct judgement!!

[Patrick Chase]

I know a guy who,as a joke,makes accurate as can be infill planes with those joints holding the steel bottoms onto the brass sides ! I mean,it is NICE WORK,TOO!!!!

Wow, that is one time-consuming joke. It's a comparatively easy joint to execute accurately by machine since most of the surfaces are circular, but even so...

Personally,the first time I ever saw those joints,I thought they were ugly,somehow. I was 18 at the time,so I MUST have made the correct judgement!!

They're ugly IMO. It's a classic example of a design that was entirely determined by manufacturability. It's no surprise that the Knapp joint died a near-instantaneous death when somebody figured out how to machine conventional dovetails.

[steven c newman]

I remember an old FWW article, about building a "Campaign Chest" out of Bermuda Cedar? Used a special kind of dovetails, too. Called them "Bermuda Dovetails"....and they were not machine cut, either...

[Jim Koepke]

I have cut a joint based on dovetails (saw it in FWW) with heart shaped pins and call them lovetails:

lovetails.jpg

Some were used to decorate the joinery on a cabinet in our laundry room.

Here is my post on making them:

http://www.sawmillcreek.org/showthre...-and-Dovetails

The layout starts in post #7.

jtk

[Bill Houghton]

If I recall correctly, Foine Wooddorking did an article on that style of drawer joint, and even included a discussion of a (rather complex, as I recall) method of replicating it in the home shoppe.

[Bruce Haugen]

image.jpeg

I assume you're referring to Stephen Thomas' "loopy plane."

I know a guy who,as a joke,makes accurate as can be infill planes with those joints holding the steel bottoms onto the brass sides ! I mean,it is NICE WORK,TOO!!!!

[Lee Schierer]

They are also called pin and crescent joints and you can make them using a router template.
pin & crescent.JPG

I found some interesting reading here. Here is a portion of what I read.

" Several inventors were hard at work on the problem in the 1860s and most concentrated on trying to duplicate the hand made dovetail using a machine – that is until Mr. Charles B. Knapp of Waterloo, Wis., applied himself to the task. He did some creative thinking and solved the problem not by duplicating the dovetail joint but by inventing another type of joint entirely that was at least as good as the dovetail and could be made by machinery. The joint he came up with has several colloquial names – scallop and dowel, pin and scallop, half moon – and all describe the new joint, which looks like a peg in a half circle on the side of a drawer. If you look at much old furniture, you undoubtedly have seen this unusual-looking arrangement and wondered what the heck it was. Now you know – it is a Knapp joint.

And knowing that you also get some very valuable information about the age of the piece on which you saw the joint. Knapp patented his first joint making machine in 1867. In 1870 he sold the rights to an improved version of the patented machine to a group of investors who formed the Knapp Dovetailing Company in Northhampton, Mass. The investors proceeded to make further refinements in the machine and actually put it into production in a factory in 1871 where it proved to be a technological miracle. A skilled cabinetmaker could turn out 15 or 20 complete drawers a day. On a really good day, the machine could turn out 200 or more and work more than one shift, if necessary. The drawer department had finally caught up with the rest of the factory."

[Mike Henderson]

I remember an old FWW article, about building a "Campaign Chest" out of Bermuda Cedar? Used a special kind of dovetails, too. Called them "Bermuda Dovetails"....and they were not machine cut, either...

Bermuda dovetails are much more complex than a Knapp joint. And Bermuda dovetails are made by hand.

Mike

[Peter Christensen]

My father repaired antiques for the last couple dozen years of his woodworking career. I was working in the shop during the summer break in high school, mostly to keep my mother from killing me, stripping furniture. A chest came in with those joints that was missing a drawer. My father made the new one by drilling into the edge of the drawer front with a spade bit and then drilled out the spade bit's point part of the hole for a matching dowel. For the side he band sawed the drawer side scallops and drilled a hole for the dowel. When done it was a good match for the original.

[Patrick Chase]

Totally a nitpick, but...

Those are pin and cove dovetails, or the Knapp Joint

I realize that you're simply describing common and preexisting terminology here, but isn't "pin and cove dovetail" a misnomer?

As I understand it the key feature of a dovetail (in woodworking as well as other applications) is that it implements mechanical interlock by means of an outwardly tapered tail, i.e. something that looks sort of like a dove's tail. The Knapp joint doesn't have that, but instead interlocks by means of the pin and matching hole.

[Derek Cohen]

Hi Patrick

That is what the joint was called. I have not seen one taken apart. I assume that it is essentially the same thing as if one dowelled the sides. The pin would refer to the dowel and the cove to its formation (I assume).

Regards from Perth

Derek