So, what material(s) do you use to make drawbore pins? More importantly, HOW do you make them? I have been labouriously riving them out of oak and driving them through a shopmade dowel plate, which works okay, but doesn’t make for an overly smooth (or often straight) pin.
Chris @ www.flairwoodwork.spaces.live.com
– Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. – Albert Schweitzer
Replies
I use white oak and the LN dowel plate. Have not made many, so have not thought of any alternatives.
Mike
Chris,
Like Mike I use the LN dowel plate to home-make the dowels. I make them out of a number of woods including oak, although those more splelky timbers tend not to produce a nice smooth round unless one is very careful.
To be honest, to get a decent dowel one has to almost size the start-pieces to dowel size before using the dowel plate!
I make sure I use a piece of wood that has straight grain with no wiggle, pin knot or split.
I cut square bars to 1mm oversize (i.e if the diameter of the dowel is to be 8mm I cut 9mm X 9mm bars).
The four corners are then planed off to make an octagonal dowel, still oversize.
The bars are cut into pieces no more than 2.5 time the length of the needed dowels. (Thin dowels such as 5mm are 1.5 X the intended final length).
A blunt point is made on one end, preferably with a pencil sharpener. (I got a collection of 6 metal ones, for various pencil diameters, from an art shop). A pencil sharpener makes an even cone, which makes starting the dowel through the middle of the dowelplate- hole automatic. An uneven point, such as one made by whittling, risks de-centering the wood so you end up with a "flat" down the length of the dowel.
The blunt point goes in the dowlelplate hole and is tapped through with a small plastic-faced mallet, keeping the dowel-piece as square to (upright in) the dowelplate hole as possible.
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This is a time-consuming proces but does produce good quality dowels with no flat or ragged sides.
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I envy the green woodworker, who may use an oversized splinter rived off a small plank. The undersized hole that the dry splinter is banged into merely deforms to match the splinter's shape. As the greenwood dries, it grips the splinter even more firmly.
Some greenwood lads use a bit of willow, as this also bends easily when the drawbore is first made (with slighty off-centred holes in, say, motsise and tenon) but also as the offset increases during drying-out of the greenwood.
Lataxe
Mike and Lataxe,
Most of my pins turn out a little wiggly looking. My shopmade dowel plate is a piece of 1/8" steel in which I bored an appropriately sized hole in and drive the dowel though. I cut the stock a shade wider than the pin's final diameter and chamfer the edges and also the leading end with a pencil sharpener. Do you feel that the thickness of the LN plate has anything to do with the straightness of the product?Chris @ http://www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Chris,If you have a look at the LN description of their dowelplate you'll notice that it has "6 degree clearance tapers" at the exit side of the holes and only the first little bit of the hole has straight sides, which allows the top to be stoned to re-assert sharp edges around the entry side of the holes. As the LN blurb says, the plate is so hard, one is unlikely to need to sharpen it in a lifetime of normal use.http://www.lie-nielsen.com/catalog.php?sku=DPSo, the thickness of the plate doesn't seem to be an aide in keeping the blank straight as it gets knocked through - only the top little bit of the hole is cutting-then-gripping the wood. What seems to matter is a straight blank to start with, of even size and with that pencil-sharpener cone at one end. Is your home-made hole perfectly round though.....? But as Ray's post points out, a dowel need not be neat to do the job of drawing together and holding a joint. It's just that our modern aesthetic tends to want to see a regular round end rather than a raggy-looking one.These days, most of mine get covered with a square plug anyway, which plug is delibrately quite rough-looking on it's end (a pyramid cut with a chisel) or a nice G&G style "square blob". However, I still can't help wanting the dowel underneath to be a good fit all round. Perhaps it isn't that important for the strength of the joint, though? Lataxe
Lataxe,
Most of my drawbore joints so far are in bread boards (the kind you cut on), so they are high visibility. They are also through drawbores, so I want a good fit on both sides. Perhaps an ugly pin covered by a nice plug is the answer.Chris @ http://www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
I do not use them very often and when I have used them they have a square head for decoration. I plane the pins square (or cut on my small bandsaw) and then turn the round part of the peg on my really cheep mini lathe. The little mini work great for what it is. I like using it even though I have to push the chuck to get it started spinning. A little break from the norm is why I bother doing it that way.
I use dowels of the same species as the stock .I put a slight point on the end in a pencil sharpener.
mike
chris,
Interestingly, most of the old ones I've withdrawn for repairs have been whittled, still showing the small flats or facets along their sides. Typically that are tapered along their length as well, making it easier to drive them, and less likely to split the mortised member they are driven thru.
I've seen some pins that have a peculiar characteristic shape to their ends (the end that is on the show surface of the leg). This is a taper about 5/8" long that has apparently been squeezed into the pin, by something like a pair of pliers, acting like a swage, to size the pin to the hole that has been drilled. Frequently, these swaged pins look as if the two halves of the swage were not aligned exactly, leaving the end of the pin looking like two C's facing one another slighly off center, rather than like an 0. If the pin is significantly harder than the wood of the joint, this will deform the hole to the distinctive shape. I'm still looking for a pair of those pin swages, tongs or pliers. They would be a real whatsit for a tool collector.
Ray
Chris:
Perhaps a bit long-winded way to answer your questions, but here's my $.02.
True drawbore-pinned joints are, IMHO, better suited to architectural applications, like timber framing. In those uses, the pins were riven from green wood (typically white oak) so the pin could bend around in the offset holes and act as a spring to tighten the joint. Later, when the pin dried, it hardened in its crooked state so it was virtually non-removable, short of drilling it out.
Furniture joints are usually so small, you really can't get enough spring in the pin to allow it to conform to the non-linear path of the offset joint parts. It simply crushes the wood fibers instead. And using green wood pins is a bit of an issue as well. So I rarely draw bore furniture joints -- seems like a lot of extra work for less than ideal results.
That said, I do make a TON of pinned M&T joints. Most of my work these days is Arts & Crafts, so the pins are usually 1/4" or 3/8" square. I just cut 'em 4' at a time on the TS with a fine blade and they are sized to fit the corresponding bit sets for the mortiser. I sometimes drill the holes on the machine and other times, drill them "by hand" after normal assembly. To do the latter, I drill a round hole with a normal drill bit and chase the hole by driving the mortise bit in a little at a time with a mallet, cleaning up the waste as I go. (I just finished a piece with 52 of these hand-drilled square holes.)
Traditionally pins for these joints were made from square stock with the corners whittled away with a small knife, and driven into round holes. (Or so I learned in my days of museum work oh-so-many years ago.) If the maker wished, he could leave the last bit square. When driving the pin into the hole, the squared-off "head" would cinch tight in the hole, squaring it off a bit, so you didn't need glue. (If you look closely at antiques, you can often see that the hole was round and the peg was square. The proverbial "square peg in a round hole." I've even seen triangular heads.) Otherwise, the head was whittled round, but left just a bit larger than the rest of the pin - which was shaped to be not particularly snug in it's hole - again to act as a "head". Think wooden finishing nail. Kept the apprentices busy. ;-)
Same deal for a true drawbore. The pins were tapered, and only the head fit particularly tightly. Otherwise, you'd never be able to drive it into the offset hole without spoiling the offset on the tenon. Modern shortcuts ignore the practical requirements of this joint in exchange for avoiding the alternative -- doing actual (sometimes fussy) hand work requiring some level of practice and skill. ;-)
Mike Hennessy
Pittsburgh, PA
Mike,
Thanks for your two bits (worth 25-times what you thought!). I've never heard of or thought of driving a hollow mortising chisel by hand. That is what you do, right? Are your pegs blind or through? I like your idea - it seems very simple, though not a drawbore. Because the pins don't need to be flexible, you can use whichever material you like.
Driving slightly oversized whittled pegs into round holes would probably work best if the pin is harder than the other wood, right? If they are the same hardness, I suspect the pin would break if there was no room for compression.
It is a real art making drawbore pins that look clean from both sides.Chris @ http://www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Chris,I've used the Mike method to make through square 'oles with a mortise chisel and a hammer. I found it difficut to avoid breakout on the far side so went in from both ends. Even with a a round hole pre-drilled as a guide, I still found it difficult to make the two square holes align perfectly where they met in the middle.If you take the bit out of the mortise chisel and put in a round bar that is just a tidge less in diameter than the round guide hole you've drilled, it does help to align the square chisel holes central to the round holes and hence with each other.I confess to having reverted to a round hole and dowel capped by the square plug, which needs only 3-5mm in depth to stay put whilst not interfering with the function of the dowel. The non-show side is left uncapped.Perhaps it's also the case, as Mike mentions, that joints in "drywood" furniture don't really justify (bent peg) drawboring so much as (straight dowel) pinning.Lataxe
What Lataxe said. I just drive the hollow chisel through about 1/4" at a time, withdrawing it after each 1/4" or so to clear out the chips that will clog the chisel big time if you try to take too much at one shot. (I use the "dumb end" of the drill from the set, inserted from the back end of the chisel, as a ram to punch out any chips that get lodged.)
Most of my through holes, like for breadboard ends, can be done on the mortiser, since joints in the carcass are rarely seen from both sides and can be blind. But if you wanna do a through hole by hand, I'd work it from both sides. And, as Lataxe implies, it's harder than you'd initially think to get that square chisel to follow a round hole exactly. It tends to wander towards whatever corner bites the most. Interesting suggestion about using a pin through the chisel to guide it in the hole, but it seems to me that that this would cause the bit to jam, since there would be no place for the chips to go. Still, I think I'll give it a try.
As for the pins being harder than the wood, it doesn't make much difference what you use. Both the pin and the joined piece will compress and deform somewhat, with the softer component compressing a bit more. The pins are cut long to start with and the oversize section is only driven in a tiny bit until it jams tightly, and then it's trimmed off flush. However, IME, you gotta be careful with brittle woods like, say cocobolo, since it's a PIA if the pin shatters when it's 1/2 way in. DAMHIKT. ;-(
And just to reiterate what I mentioned in my first post, I don't think draw bored joints do much for you in glued furniture joints. You'll get much more clamping force from your clamps than you will from a 1/4" wooden pin! And modern glues will hold the joint tightly as it was clamped. Draw bores were used in P&B construction since you can't very well clamp and glue an 8"X8" beam 20' long. But if you do make through draw bores, don't fixate on the pins fitting perfectly from both sides -- or even one side! Take a trip to a museum and look closely at some old handmade pieces. You'll quickly notice that the pins definately do NOT look like they were turned on a machinist's lathe. Perfect pins in perfect holes = power tools. It's one of the first thing I look for on old furniture to help figure out exactly what I'm looking at.
Mike HennessyPittsburgh, PA
chris,
If you are driving a square peg into a round hole, I've found that sizing the peg accurately pays off. An undersized peg leaves gaps at the flats of the peg. And oversized pegs tend to split the cheeks of the mortise if they are at all thin. Like Mike, I usually don't drawbore pin, unless I'm replacing one on old work. For whatever reason, the furniture form where I've seen drawbore pins used most frequently is in table frames. But for our purposes, clamping up the joint and pinning right after assembly allows one to remove the clamps immediately (as long as the assembly is handled gently), and move on to the next job. Frees up clamps and shop space, especially when doing multiples, like a set of chairs.
Ray
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