Drawbore Pins

[dunbarhamlin]

Wanted to drawbore some M/Ts, so was looking on the S/H market for drawbore pins - I'm sure just a year ago they were being given away with penny nails, but this time when I looked, didley squat.

On the PLUS side - I've found there are TWO modern makers.
Ray Iles has them ready to go, with either carver or octagonal handles (approx forty quid a pair depending on handle).

And Dave Jeske will make them to order, and is contemplating making them a standard offering. (Competitive especially considering they're a custom order at the mo and the cost of intercontinental bore stick missives ( sorry))

So I have Ray's in my sticky paws already.
(And Dave's sorting a pair of small ones)

Suppose for completeness, be useful to mention a source for suitable drifts/alignment pins to make some myself - alas, I couldn't find these either - any know of a UK source?

Cheers
Steve

[jay]

Not really a traditional method for Mandolin construction, but hey... I found drift pins in a local tool shop last year - sadly now closed down so not much help, but they are out there.

So are Ray's pins a funny shape for better twisting or straight and circular with a point on?

--edit--
Searching Google for the term 'drift punch' seems to yield better results, 'taper punch' is better yet.

[dunbarhamlin]

;D hahaha I'm sure someone has tried it. I do have a mandobass pencilled in for myself when I can get time - but sorry to disappoint, not even that will have a drawbored neck joint (though it would certainly be solid enough!)

No, using them for some furniture.

Ray's pins are fab - just as one might expect.
The taper is indeed eccentric. (Got a pic somewhere - though sure sure it'll show it clearly - hang on)

[dunbarhamlin]

Hmm, doesn't clearly show the pin shape, but anyway:



(I really do need to sort out the camera thing - this pic is from Ray)

[jmk89]

I made mine using taper punches and following Christopher Schwarz's step-by-step article: www.wkfinetools.com/contrib/cSchwarz/z_art/drawBoring/drawBoring4.asp

[mrgrimsdale]

I've got one left from a set of 3. 5/8" dia. Blacksmith made. End turned over so you can hammer it back out of the hole. Most often (only) used for string to newel post because of the uncrampable angle.
Look a bit over engineered those Ray Iles jobs! Blacksmith would do it a lot cheaper I'da thought. Just a bit of mild steel with a taper hammered for about half the length, plus bend in place of handle



cheers
Jacob

[dunbarhamlin]

Now that is cool.
The thought of a local blacksmith sounds fab - unfortunately ours closed down a few years ago, otherwise I'd certainly be a customer.
For tools that'll serve well until the Treasury Solicitor auctions them off in forty years, I think forty quid the pair is OK, and it's still supporting (relatively) local craftmanship.
Cheers
Steve

[argus]

May 27, 2008 1:22:54 GMT dunbarhamlin said:

Wanted to drawbore some M/Ts, so was looking on the S/H market for drawbore pins - I'm sure just a year ago they were being given away with penny nails, but this time when I looked, didley squat.

I don't know where the metal pins have all gone .... they used to be plentiful and cheap in various odds and sods boxes.

Thirty or forty quid a pair for nice new ones is a bit expensive unless you use them all day every day.

One alternative (if you have access to a lathe or a friendly turner) is to turn tapered wooden pins to suit your needs from odd off-cuts of hard wood. This will usually help with alignment and tightening the shoulders of the tenon.

Knock 'em in, knock 'em out and when they're a bit ragged, toss them on the fire and make some more.
.

[mrgrimsdale]

People 'inherit' them one way or another but don't know what the are and can't see any use for them, so chuck em away. If you got a set like my one you might think they were marquee tent pegs or something.

cheers
Jacob

[mrspanton]

I have made hundred's of draw pegged mortice and tennon's joints and have never used any of those steel pins. How or why do they make the process easier. I just rely on the strength of the oak or ash peg to do the business. I make my pegs to be taper'd gradually the full length from fat to thin at the point, not a parralell dowel with just a small point like a pencil. If I'm missing something please tell me. (unless its to hold eg a post firm up to to a plate while you scribe out the positions for a brace, or something like that)? But then you could use a sah clamp to do that. Or a ratchet lorry strap on a big joint
cheers Jonathan

[engineerone]

must confess i understand jonathon's view better than the need for drawbore pins.

can't imagine local makers using metal bars when a gently tapered pin itself would do the job to perfection.

paul

[mrgrimsdale]

If I'm missing something please tell me. (unless its to hold eg a post firm up to to a plate while you scribe out the positions for a brace, or something like that)? But then you could use a sah clamp to do that.

Well you've said it. Metal pins just give you a bit more control - and you can be sure of getting them out again iwithout breaking them etc. And you can't use a sash cramp on anything off square such as a diagonal brace - or a stair string/newel post joint.
If you had them you'd probably use them but I agree you can do without.
Not sure about those expensive machined one though - looks like another tooly fantasy - and the handles would get in the way

cheers
Jacob
PS I first used draw-bore pins many years ago when I was steel erecting - same thing but with a spanner at the other end, called a 'bodger'. You'd get one or 2 bodgers into bolt holes and pull the steelwork together and then put bolts in the other holes before removing the bodgers.

[Alf]

Belatedly I'm reminded that I have what I think are three coachbuilder's drawbore pins. I'm more than a little hazy about what coachbuilding actually entails, but I imagine curved parts and such leave clamping out of the options. Anyway, they're about 6 inches long with T-handles - don't have a pic handy and can't honestly promise to get one. Depends if I can find them...

Cheers, Alf

[mrspanton]

Jun 3, 2008 5:29:17 GMT mrgrimsdale said:

Metal pins just give you a bit more control - and you can be sure of getting them out again iwithout breaking them etc. And you can't use a sash cramp on anything off square such as a diagonal brace - or a stair string/newel post joint.

But surely when you asemble the joint you do it with your oak peg, and its done, finsihed?? the mechanical power of the peg in offset holes exerts enough power to pinch the joint up if it was done right first time without need for any other mechanical aid's. Unless your doing a test fit and want to fanny about saw carving and other adjusment's? A ratchet strarp would work to pinch up angled component's if it was really necessary (the Americans call them come along's) It stands to reason, if you pinch the joint up, what possible benefit is there in using a draw pinned fixing? You might as well pinch it up tight, drill through the mortice/tennon assembley with a single hole and insert a parallel peg the exact same diameter as your drill bit, when you release the strap etc the stresses will gradually be transferred to the peg, the tennon shoulders and the area above its peg hole; in fact this could possibly actually be a better method because the joint isnt being pinched up just with the area of wood above the end of the tennon, which can and sonmetimes does pop out or snap the peg if you set it out wrong (too much offset on hard wood's), using a strap or clamp would spread the pinching pressure onto more of the overall structure. I should of mentioned when I do draw pegging they arent glued.

[jay]

I think you're confusulating drawborn construction with, well - not sure what; but some other peggy holey thing. The rhyme and reason of drawboring a tenon and mortice is to create an elastic joint that thrives on shrinkage and swelling and twisting and wracking and all the nasty things wood does after three months / years / decades / centuries. It allows a loose fitting joint (necessary in green timber as a precision joint will be broken apart under immense and continuous forces exerted as the timber seasons and possibly attractive if you want to do carcase work quickly using hand tools - there's an art to good sloppy joints, don't be turning your nose up) to be pulled tight and become extraordinarily strong and long lasting.

You don't want forces spread evenly about your structure - you want them under tension, keenly focussed right where you're working and actively pulling the joint together. Spreading forces about the rest of your frame is wasted effort.

Pins are optional (though less so when knocking together a barn in green oak). But they do allow a greater offset between tenon and mortise holes (offsetting is essential to gain the pull and elasticity; the greater the offset the better), you can jab a pin through despite seeing less of the hole and use the strength, and leverage from twisting the concentric pin to pull the joint together and bang in the peg in the neighboring (two pegs per joint) hole (snapping pegs is why you need the pin). The pin will also 'chamfer' the edges of the tenon's hole as you bash it through - making it easier to follow up with the peg.

[mrgrimsdale]

Perhaps joiners are just a bit cautious cos they don't get the practice and that's why they need pins instead of going for naked wood. And snapping pegs is why you need the pin, as jay says
In ordinary joinery it's only really ever done on stair string/newel. So you don't get to do many compared to a timber framer. Ditto furniture unless you have a lot of angled joints. Though you get those trad table tops with loose tenons joining the boards with a pattern of 4 or 6 draw bored dowels - very attractive and functional - one place where you really need it pulled up tight.

cheers
Jacob

[jay]

Pins do a little bit more for you than just allow you to test a joint and avoid losing bits of broken pegs wedged into inaccessible joints if you overcook it. You can make-do without, but pins give you more leverage to pull together and peg a joint with intentionally greater offset between the holes without the risk of mangling the peg as you try to force it through. Offset is your friend, pins act as matchmaker.

[mrspanton]

Jun 3, 2008 22:00:58 GMT jay said:

You don't want forces spread evenly about your structure - you want them under tension, keenly focussed right where you're working and actively pulling the joint together. Spreading forces about the rest of your frame is wasted effort.

I disagree with that. The whole point of assembling a structure with a varied set of components and joints (including pegged mortice and tennon's) is to transfer and spread live and dead loads evenly throughout the entire structure so that you dont get any weak spots where theres a concentration of loads or stresses at any one point that could cause failure. Joint design has evvolved over many hundreds of years to get the best ways to do this. EG the english tying joint .
As I said I've sucessfully made hundreds of draw pegged joints and I never used any iron pins. I honestly cant see any benefit in using a iron pin then remove it and replace with an oak one. If you set the joint out properly, use gradually tapering pegs, and dont overdo the offsetting the joint will work perfectly. You can have too much of a good thing, too much off set will damage your joint. Mr Newman (english scribe framer) recomends 3 to 5 mm with an 3/4 inch peg, no more than 1 to 3 mm for a 1 inch diam peg. Mr Sobon (american square rule/scribe framer) recomends 1/8th or less for hardwood's to 3/16th's of an inch or less in softwood's. And these are on joints with any thing up to 10 or 12 inch square timbers or better. Too much offset puts too much stress on the relish of the tennon and will pop it and your component is ruined. The relish will pop before the peg will break unless you had a dodgy faulty peg or it was too thin for the load's it would have to carry.
There is a schol of thought that it is better to pinch up the mortice and tennon THEN drill through both with one hole and THEN peg it which is what I thought this thread was on about . But Mr Sobon is of the view that this isnt a good method, the joint may loosen slightly as the clamp is removed. And you need heaps of sash cramps or ratchet strap's. He does mention jacobs drift thing, drift wedge which was traditionally used to draw the timbers uo to begin with, to align the holes so the peg goes cleanly through all 3 holes (mortice/tennon/mortice) without snagging or distorting.
Did U fasten the steel work together with draw pins then jake

[mrgrimsdale]

Did U fasten the steel work together with draw pins then jake

Pins to draw it up into alignment - which is why they are called draw bore pins I assume, and then the bolts in the empty holes. Amazing amount of leverage possible with 2 bodgers in steel work - sort of ratchet effect like a turfer.
I wouldn't argue with your timber framers stuff though as it seems to come from the horses mouth horses for courses etc

cheers
Jacob

[jay]

Jun 4, 2008 8:40:10 GMT mrspanton said:

I disagree with that. The whole point of assembling a structure with a varied set of components and joints (including pegged mortice and tennon's) is to transfer and spread live and dead loads evenly throughout the entire structure so that you dont get any weak spots where theres a concentration of loads or stresses at any one point that could cause failure. Joint design has evvolved over many hundreds of years to get the best ways to do this. EG the english tying joint .

And there was me thinking the drawbore pin evolved along with the joint.

Wood is nature's own carbon fiber; flexible in one direction, rigid in another. Drawboring takes advantage of this by stretching the length ways fibres of the peg (pegs should be split along the grain) around an offset arrangement of holes in timbers whose fibres are running at 90 degrees the other way. The peg has no trouble flexing to accommodate this arrangement and the elasticity in the fibres pull and hold the mating surfaces of the joint (the shoulders) together. The grain direction in the tenon and mortice sides keep them and the joint rigid. There's plenty of overhead and no terrible danger of splitting the tenon just because you're using a pin to temporarily pull the joint together (pins are sized, which limits how much force you can apply). If the tenon pops it's just as likely that you're probably using too large and inflexible a peg. And yes, you can mangle pegs in the same way you can mangle and split the ends of posts when hitting them into the ground; and they can be a bugger to get out again if the bore is blind on the far end.

You're not creating a weak point. The general forces and exertions your joint has to live with are placed on the shoulders of the joint, same as they ever are. The peg is simply an elastic device under tension for keeping the joint together.

Again, you don't need a pin; but a pin is an aid to making a better/easier joint. You don't remove the pin - there are two (or more) pegs to a joint - you jab the pin in, twist and then peg its neighbour. If you're just aiming for a single peg per joint then there is less value in using the drawbore pin (though it will still go a little way to preparing the path of the peg).

[mrspanton]

Jun 4, 2008 13:46:46 GMT jay said:

And there was me thinking the drawbore pin evolved along with the joint.

Wood is nature's own carbon fiber; flexible in one direction, rigid in another. Drawboring takes advantage of this by stretching the length ways fibres of the peg (pegs should be split along the grain) around an offset arrangement of holes in timbers whose fibres are running at 90 degrees the other way. The peg has no trouble flexing to accommodate this arrangement and the elasticity in the fibres pull and hold the mating surfaces of the joint (the shoulders) together. The grain direction in the tenon and mortice sides keep them and the joint rigid. There's plenty of overhead and no terrible danger of splitting the tenon just because you're using a pin to temporarily pull the joint together (pins are sized, which limits how much force you can apply). If the tenon pops it's just as likely that you're probably using too large and inflexible a peg. And yes, you can mangle pegs in the same way you can mangle and split the ends of posts when hitting them into the ground; and they can be a bugger to get out again if the bore is blind on the far end.

You're not creating a weak point. The general forces and exertions your joint has to live with are placed on the shoulders of the joint, same as they ever are. The peg is simply an elastic device under tension for keeping the joint together.

Again, you don't need a pin; but a pin is an aid to making a better/easier joint. You don't remove the pin - there are two (or more) pegs to a joint - you jab the pin in, twist and then peg its neighbour. If you're just aiming for a single peg per joint then there is less value in using the drawbore pin (though it will still go a little way to preparing the path of the peg).

I can see that.
I think we've been at cross purposes . When I mentioned "srtucture" I was talking about an entire frame eg a building, assembled from a number of components, I wasnt just talking about the structure of one mortise and tennon joint. There are ideal proportions-of posts/beams/braces/peg sizes mortice widths and depths etc-arrived at through centuries of trial and error (which frames lasted the longest ;D) plus compromises between ease of setting out and execution VS time/cost, what quality of oak was available etc etc. Some modern framers Eg Steve Chappel, have extended this by using structural engineer type calculations as a way to determine ideal positions for joints, dimensions of posts beams and brace's etc. A good frame has all these in a logical balanced holistic whole (and looks attractive as well ). But EG if a brace is set in right next to a scarf, or the mortice is too shallow, or the pegs are too thin, or the peg offsets are too big, rafters spaxced too far, or the plates or posts are too thin, or the braces too short etc etc then you may well get a weak sopot that will overload, rupture and cause cumulative failures even eventual collapse. EG Charlton barn was in serious trouble. It had been standing 600 year's or so. But poor roof maintenance and general decline meant that the stone footings beneath the main jowl posts were subsiding. Consequently the jowl posts in some cases were in mid air no longer resting on the stone's; the loads they had carried were being taken by other parts of the frame-the tying beams were failing, rafters starting to spread, and studs bulging (as they took much more than there fair share of the 200+ tons roof load); this was putting undue stress on joints that werennt intended to take those amount's, meaning that they in turn would sooner or later fail as well. If they had left it the frame would eventually of ruptured and collapsed. You see a lot of barns round here where the braces and sometimes the tying beam itself were removed from tying joints to get enough room to store combine's and other big machinery. To stop the rafters sinking and the walls spreading they usually added a 12 x 2 higher up with black smithed iron strapping or bolts or something, and some time's added angled knees (bolted in). I often wonder if on some ocasion some old booey a bit worse for wear from ale took his saw to the beams and ended up collapsing his barn ;D It makes me laugh to think of that, like a will hay type thing or laurel and hardy ;D
Have you ever cut english tying joints? They are pure genius. It is the best way yet devised to join plate, post, rafter and brace into one whole structural connection

[gazza]

Jun 3, 2008 5:29:17 GMT mrgrimsdale said:

PS I first used draw-bore pins many years ago when I was steel erecting - same thing but with a spanner at the other end, called a 'bodger'. You'd get one or 2 [b]bodgers

[/b]into bolt holes and pull the steelwork together and then put bolts in the other holes before removing the bodgers. [/quote]

Had a good old laugh to myself when i read that Jacob ;D
Done a bit of steel erecting myself years ago, although we called them Podgers
Have a Karma on me mate ;D ;D

I think a "Bodger" is a chair maker, Eh MrSpanton ?

For anyone who is interested, try looking for Drifts, Podgers, Tapered (pin, dowell pin, alignment pin, punch) to name a few.
Cheers,
Gazza.

[mrgrimsdale]

Jun 5, 2008 22:34:18 GMT gazza said:

Jun 3, 2008 5:29:17 GMT mrgrimsdale said:

PS I first used draw-bore pins many years ago when I was steel erecting - same thing but with a spanner at the other end, called a 'bodger'. You'd get one or 2 [b]bodgers

[/b]into bolt holes and pull the steelwork together and then put bolts in the other holes before removing the bodgers. [/quote]

Had a good old laugh to myself when i read that Jacob ;D
Done a bit of steel erecting myself years ago, although we called them Podgers
Have a Karma on me mate ;D ;D

I think a "Bodger" is a chair maker, Eh MrSpanton ?

For anyone who is interested, try looking for Drifts, Podgers, Tapered (pin, dowell pin, alignment pin, punch) to name a few.
Cheers,
Gazza.[/quote]Well blow me down - podger it is
Doesn't mean they don't call them bodgers in deepest Derbyshire though!

cheers
Jacob

[mrgrimsdale]

Another Derbyshire building site word was "pudlet". Was a few years before I found it was supposed to be "putlog" which I've also heard spoken as 'putlow' and seen spelled as 'putlough':
short horizontal piece of scaffold going in to a hole in the masonry.

cheers
Jacob

[nickw]

There's now a new supplier of drawbore pins around. Should keep Jacob happy. ;D