driving the pins

driving the pins

The post about making the pins for drawbored mortise & tenon joints brought a couple of comments, and a couple of questions. First & foremost, the moisture content of the pins – bone dry…gotta be. I shave mine dry. I split excess straight-grained oak into pin blanks and then store it around the shop. They are small-cross-sections, so dry quickly…but in any event, I always have several piles of them around – from green to dry.

They do have to fit the holes, but the taper in their length makes this easy enough to acheive. It doesn’t hurt to have a piece of scrap stock with a test-hole bored in it, and check your first dozen or so pins in that hole…typically beginners make the pins too stout.

Alexander points out that using a shaving horse & drawknife to make them makes the taper easier to achieve.  But JA is working from stock that is easily 3 times the length I use. It’s a trade-off.  As far as my method requiring experience and skill, well…I am reminded of a quote I once heard the folksinger Claudia Schmidt repeat:

“Good judgement is the result of experience. Experience is the result of poor judgement.”

(I figured it’s from Yip Harburg [If I Only had a Brain] but on the web I’ve seen it attributed to Twain. Don’t think it’s him…but maybe need to look at Puddn’head Wilson again)

Hmm. I adopted this method of shaving pins when I saw it in a sixteenth-century woodcut. I find it really works, and splitting the stock is very easy in such short lengths. You can often split it down to nearly the size you need.  I say make your pins that way, and you’ll get good at ‘em. Shaving them from long stock with a drawknife will get you good at shaving them from long stock with a drawknife…either way, make them dry, make them tapered.

It is not a wet/dry joint like in Alexander’s post & rung chairs. The action of the drawboring is what makes the joint work, not a moisture content differential. for more on the drawboring, see http://pfollansbee.wordpress.com/?s=drawboring

(on the right-hand side of this blog is a search button, way down towards the bottom. Let’s see if the above link works to get readers to the previous entries on the subject.)

drawbore pins

drawbore pins

 

I do use drawbore pins to pull the joint together first, this allows me to check the joints and make sure everthing is as it should be, before I put any wooden pins in. Some folks think these steel pins will wreck the drawbore, but I’ve never had a problem with them. Alexander found these pins at Sears many years ago, and handled them for me. Cheap & effective.

 

joint ID

joint ID

I also often use a numbering system for making certain that the correct tenon is in the mortise. Here just the mortise chisel chops Roman numerals to ID the joint.

 

Here’s the inside of a recent stool showing the trimmed pins, the fore plane surface on the inside face of the rail; and the inner shoulder of the rail not quite hitting the stile. Also these pins are staggered in height, so as to not interfere with each other.

interior of stool frame

interior of stool frame

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