Wedges, I've on the past couple projects used some half round wedges for some through tenons, On my latest project I have included rectangular tapered wedges, at a 1:8 ratio. 3" to 4" in 8 inches of length on the 2 inch thick wedge. After watching this video a few days ago and seeing the failed wedge get sucked in the the mortice in failure, I decided to give the traditional wedge a go. Specifically the white pine wedge in the photo at the end of the video.
My partner just left for New York last week to finish part of the frame we are working on there with Tim Rau of Pleasant View Restorations. Tim specializes in "Dutch Barns." We have consulted on a few together and he is taking another one down now for restoration and resale. There aren't many of these left and he may keep this one too for himself as I think he has 2 of them already on his family's farm south of Albany.
There is much debate about the "wedge and peg" reasoning in these frames. The common understanding is the wedges are used to draw the large "anchor beam" tight into its receiving post and then the pegs further secure it fast. There is evidence that some are also draw bored as well as wedged (??) Some also are absent the pegs and only rely on the double wedges for securing them to the post...
Mostly in the Dutch barns where this construction was employed, the so called ankergebint, both wedges and pegs got used, anyway historically. I don't know of an explanation for what seems a redundancy but in the stress testing videos I can say this, orienting the wedge to run parallel with the post doesn't seem as good an idea as a wedge or wedges that are pressing across the grain of the post though I admit to having done it that way myself. Also, and what I have never done, it doesn't seem pine or softwood is so compatible with this choice of joint. The wood used in the ankergebint construction is typically oak of none to high quality, usually from the farmland or local forest.
I am not sure how many of these you have been in in the New York state area, but I would like to know (your rough estimate?) how many comparatively had wedges and trunnel compared to no trunnel and only wedges from the ones you have been in. I am speaking of only American examples for this frame type, and your comparative examples of "softwoods" to hardwoods...We see mainly softwoods in the New York area, and one that may well be Yellow Poplar that I haven't yet examined.
As for overall comparable compatibility...both vertical (mainly furniture) and horizontal (primarily timber framing) is done in softwoods...and not hardwoods...My rough estimate is probably something between 60% softwood vs 30% conservatively (thereabouts) when all comparable joint configurations of this wedge form/style are compared. Point of notation...I am not just consider this joint from an American/European statistical commonality but overall use in timber framing cultures. I think many forget that the dominating number of timber frames built (historically and today) are east and south of the Anatolian peninsula and not in Europe. So when we speak of joint applications, durability and use, we should consider the entirety of the craft.
There is on the one hand, dutch barns, which I guess is what they've got to some degree or another over there in New York and that area, and there is Dutch barn which I was going on about and which really doesn't even exist as a type and is why I tried to be more specific by saying ankergebint which is a description of the construction employing the wedged and pinned joint and not the whole barn. But somebody brought the term up, I guess in the first sense that I mentioned, and that made me wonder where the term came from, and might that be helpful in understanding why the joint would be wedged and pinned. Could it be, I thought, that the term dutch barn has something to do with Dutch barns, in the second sense if you follow my meaning. As far as using the wedge that is parallel to the length of that post, I'm not the one to say how commonly it gets done that way or not, I was just giving my observation of what I saw going on in that demo.
D.W. you asked some great questions and those are many I (et al) have wondered about. Additional, we are getting to the point in "timber framing academics" where solidifying how we classify (or perhaps taxonomize would be a better term) the different frame styles now and through history, perhaps breaking down "form" (aka genus) and "style" (aka species) in a more clarifying fashion. I know this topic has come up a few times among academic architects and social anthropologists I know.
As for "type" which I have come to understand architecturally as "form and styles" there are very distinct Dutch, Germanic and related timber frames that are clearly identified not only by chronological placement but structural elements as well. "Ankerbalkgebint" is one such form, comprised of several styles with key feature elements such as"ankerbalk," often used (and debated) to identify them within historical time periods, and cultural placement. The "Ankerbalkgebint" is not just religated to Dutch and/or Germanic culture but further has developed (actually way before the Germanic forms) in other cultures as well, and of course, under different nomenclature. Yet one could reason that the Germanic forms are the most "distinct" in character and individual style, as a primary timber element within those frames.
The "term" itself is allusive to me, yet as I study deeper into the Germanic and Asian history of this form and style of timber framing, I am sure to discover more. You and many of us are still perplexed why the majority (not all) get both trunnel and wedge. As I spoke of earlier, the consensus thus far is that the wedge was employed to draw the joint extremely tight and then the trunnel bored and placed. The "horizontal" configuration of the joint as shown in the shared video I only find in furniture and in very rare Asian timber frame joints (actually I can only recall one from memory in a roof system and perhaps another in a ship's assembly??)
"Dutch Barns" (as they have become known as here in the United States) are indeed a very strict building form of several styles within the historical Dutch - Germanic Timberwrights that settled certain regions of New England, with a concentration in New York, Pennsylvania, New Jersey and outlying areas. Now rare do to neglect and alterations in their pure form, they are distinct and easy to recognize in "form and style" by those that study them in depth.
I think we can agree that the vertical wedge in building construction will fail earlier than wedges pressing across the grain of the post. It's telling that in the one video I notice that figure who is something of a celebrity in the woodworking scene mostly connected to folksy furniture, but I'm really not so familiar. Anyway, I know the joint as shown as the standard connection of the stretchers to the leg construction of traditional furniture makers workbenches allowing them to be easily disassembled and in that instance it makes perfect sense. This is the very construction of my own workbench in fact which will never get 4000 lbs. of tension applied to it.
It, (your link Tim), helps me understand one thing, "dutch" definitely doesn't come from the Dutch themselves. It seems more like an English conflation of the word Deutsch which is what the Germans use for the English word German. In fact both words, Dutch and German and totally English as far as I know, but I'm no etymologist, just an English speaker who speaks Dutch (Nederlands).
The Pennsylvania Dutch are actually Deutsch, and it was recorded wrong at Ellis Island, or so the story goes. Jack Sobon calls Dutch barns "Lowland European" barns.one of the New York Dutch barns I restored had German carpenter's marks, and was built for a Jacob Duesler (sp).
Any Dutch barn I have been in, or have seen photos of, has had both pins, and wedges. Also, they have been predominantly white pine, with oak (red and white) braces and door posts. Pitch pine, a hard Southern pine, was common in NY, and I'm told oak was fairly common in Northern New Jersey. Can you imagine raising an oak H bent with gin poles?
We have raise (and lowered) a few that way...It is scary the first few times...Now just use a "scaffolding tower" to do most of such things and of course it really helps to have the supper compact (and smooth operating) modern rigging blocks that we have...Our work in the Arborist industry (where a percentage of our timbers come from) have served our needs well in developing more advanced "rigging systems" for timber framing...
Your observations about wood species is exactly what we find...The last few "Dutch Barn" (more correctly "Germanic Barn" I agree) from New Jersey where hardwood, and I think that is where the "Tulip Poplar" one is??...The rest being mainly White Pine, Hemlock, etc...
Do you have any view, or theories why the "wedge and trunnel" system?
On a bit of a tangent...It sure would be a lot more work to create a wedge parallel to the post grain. And certainly seems like a more delicate joint. That video really demonstrates that it doesn't seem that the wedge is the weak point when oriented across the post grain. In the video, the "post" actually failed, which was surprising, as I expected the tenon relish to fail. What would be the reason to create a TF joint with the wedge parallel to the post?
In my opinion, the rationale regarding the wedge and trunnel system would be as follows: The wedged through tenon is a joint which I have always recognized instinctively as exceptionally strong, and practical observation has only strengthened that assumption. While I don't think that the pegs are necessary to the joints function, I think that they would be added because... "why not". It's certainly not hurting anything and an extra 3 pegs or so per joint is not an unreasonable amount of additional work for such a critical joint, even before power tools. Plus I think it gives an additional structural fail safe. Would it not cross a builder's mind that wedges are not too difficult to knock out? If it was me building those New World Dutch barns I would peg those through tenons for no other reason than peace of mind. In my mind, timber framing derives a lot resiliency through well placed structural redundancy.
Loc: the Netherlands
The wedged through tenon is a strong joint but does weaken the post. This is the reason given in at least one source on the joint I have read why it is not used in softwood building work, anyway in these parts, and only found in oak frames, which it seems is not so on the USA side and also no longer adhered to in new buildings as I have seen it here too. What to make of it? I don't know, but at the same time am not one to readily disregard the old-time localized body up built-up knowledge in exchange for what I see as a muddled globalized confusion irrespecutful of conditions in the particular instance. (Ok, call me a timber frame nationalist, I admit it.) I have to say I am skeptical of this "why not" rational for the wedge & pin combo. Usually variations in joint configuration are meant address particular aspects of placement, material and function along with habits, culture, environment. But take the wedge which is parallel with the post for example. One possible reason I gave earlier, another might be where the post, or lets say vertical member, because as Jay says it really is a joint more appropriate on a smaller scale, is small across grain and orienting the wedge in the length gives more bearing surface. I think the videos represent unrealistic situations and so we must disregard them outright. And back to my workbench but it could be any of the workbenches coming out of Scandinavia, where the vertical wedge makes perfect sense, in softwood by the way, when you consider the dimensions of the legs and stretcher configuration, the legs so narrow across the grain that wedging that way would be asking for trouble.
I think it's a good mental exercise in the very least to be able to justify the use of any joint. All the better when that justification has some historical grounding or established usage pattern that can be identified. What are we left with otherwise? Whim and an arbitrary selection process. Not much of a design concept if you ask me. Or even worse, pure exhibitionism of a flashy joint that really lets the viewer see what a craftsman it must have been who put this thing together. In other words it is the joinery to a large degree that defines the craftsmanship, is it one of authenticity or just ego. I'm sure that everyone doing this kind of work goes through this process to the one degree or that other one.
Perhaps an engineer could answer this question, how much pulling load is actually applied to the post, exerting pressure the tie beam joint? And with these hydraulic pulling machine they test with, how much more pressure is applied to the joint that will be seen in the life of the structure at worst cast scenario? Is it like testing tire load ratings and putting a load on a tire to the point is bursts where we would see failure in broken springs, or bent things before the tire blows? I am presuming these test are performed to build number that will lead to specifics, a broken joint is not necessarily the end goal, more degrees of failure at given pounds of pressure.
Peg and wedges, a belt and suspender approach, I wear both, btw. The belt holds things and the suspenders keep my pants up when in use and when the zipper is run down for other purposes, a perk, I guess.
I can see times where just pegs could fail with relish blow out then there is not back up plan, a wedge adds a back up plan in times of need. Were the original builders adding a wedge for the future, or unforeseen needs, like shifting foundations and the such?
Yes I get the point of the theoretical exercise of joint busting aside from it being a lot of fun in some way perhaps. Soort of like, nobody actually wears that crazy Paris cat-walk kind of clothing. But belt and suspenders? I could never really get my head around that one, still can't. It's why you have pocket-knives, for those times when your outfit includes over-all or suspenders and you leave your fixed knife or your multi-tool in its belt holder on the bureau. I look at the joints cross adaptation. Could it be that it began as a remedy addressing something very specific like the various forces exerted on a particular component of a horse driven mill in and around the late middle-ages, and from there just got taken into the barns that got built. Today we still got barns but no more horse driven grinding mills, well, an acquaintance is building his but this is an exception.
Having strong ties to the Textile arts and trades...they very much do where those "cat-walk kind of clothing"...actually quite often...just not in too many areas you will find many practicing Timberwrights ...Greenwich Village, Milan, Hamptons, Beverly Park, Marseille...to name just a few...have "nightlife" and social gatherings where these types of attire, especially for Women, are very common...
The "Belt and Suspender" metaphor was about perfect in my view, as they do work much better together if you carry stuff in your pockets...Actually, when you really look at all the folks that do where suspenders, especially cultural groups I have always worked with through the years like the Amish, River Baptist, Mennonite etc....all...wear belts and suspenders. I suspect for the same reason Tim shared (and their common cultural habits in attire.)
From the literary and conversational comparative the reason we have the "peg and wedge" setup...is very much for that same reason...Wedges are much better at really drawing a joint tight. Nevertheless wedges can work themselves out of place (in some applications) when in the horizontal position. This is why we find the vertical orientation so often in furniture, which actually must endure a great deal "human created" tectonic loading...A horizontally wedge on a "Trestle Table" will need more "tapping in" and retightening than its vertical wedged cousin...I should clarify from one of my comments above that when I said this joint was "rare" in timber framing...I meant in exactly this configuration...As for "vertical wedging" joints in general...they are extremely common and in many different styles and applications...yet outside the context and understanding of most "Western Timberwrights."
We are actually only getting to "scratch the surface" of testing and videos of them, when we are lucky enough to get folks like Ben and Joe of FTET...Joe is our current PE on the project we are working on currently. We spoke of this very video over lunch just a few months back, and there work testing these many joints is invaluable to the rest of us in the field working with timber frames...!! For those of our readers that really like this type of testing and timber frame examination, I would strongly encourage learning some other languages as it relates and applies to our craft. The Japanese (et al) not only "timber frame" way more than most other timber frame cultures (now and historically) but they produce literature and video of actual competitions to present different wall assemblies under load and failure. They do similar empirical comparative analysis of traditional joints like we get from our wonderful FTET gang as well, at many such events. They even have competitions where the only event is to see how well you can tune and use a Kanna (plane.)
Here are a few more video (tip of the "iceberg") that folks may find interesting...
I added this one as you can see the many examples of both horizontal and vertical wedging joints that are used...
This is an example of "Nuki Beam" testing (also a wedged joint and why I included it here in this post)...one of the most common "horizontal bracing" modalities employed in timber frames architecture, and perhaps the oldest in application and understanding, as it is highly resistant to "catastrophic failure" in tectonic loading. It is a very keen point of interest even today as there is a very clear rift that has formed between "big construction businesses" and their "industrial housing" methods as compared to the traditional builders still holding out that these "traditional systems" (overall) are much better in application. The draw back is that "Big Industry" can manufacture and sell these methods as profitably and fast as they can lesser "stick framing" and metal fastener methods...It is a normative "building culture" as much as it is actual aspects of good practise....
Point of interest to the many groups like it in Japan...
Mortise and tenon joint testing
Another spline joint with "vertical wedging" common and one I like to use on frames...
Yet, to actually implement a true "wedging force" I think the "wood element" being driven...whether square, rectangular, round, or having some other general geometric shape...must be forming an ever increasing "inclined plane"...(i.e. a wedge)
We know that a "screw" is a type of wedge as it maintains all those elements of having multiple "inclined plane" within its helix.
So...is a drawbore peg/trunnel actually a wedge??
There is wedging in the beginning, yet after that it seems to me to act more like a "spring shaft" or perhaps even a "cam" of sorts...not a wedge because the sides of the trunnel are typically of a consistent geometry...
I have seen "square wedging pegs" that also "draw bore" yet those seem uncommon for the most part...
It is truly awesome, each decade that passes the more I learn and get to observe in the area of Asian joint design modalities.
The "keyed spline joint" or more apply translated as Shachisen tsugi ..."plug joint"...Shachisen for short and most Diaku would know what you are asking about...Does not fail the way most would think...
Like so many of the Asian joints, particularly in Japan with their massive tectonic load needs...the joints are meant to "stretch" and fail very slowly...Thereby rendering the building much more enduring and flexible...compared to "oblique bracing" which not only put extreme fulcrum forces on most joints near it (especially when under 4' in oblique length...the also fail rapidly and catastrophically once over loaded...They do make a frame ridged, yet there application in Japanese framing (they do exist) are in very key and critical locations that you typically do not see in Western framing systems...Glad you enjoyed the video...
Loc: the Netherlands
I chop a point on the peg and then bevel it 1/3 of its length which is twice the thickness of the beam. But there is no taper after that, no intentional taper at least but generally those pegs are so irregular. The point and bevel I see as guiding the peg into the off set hole of the tenon and then gradually initiating the draw so I wouldn't characterize the action as wedging at any time. A tapered peg though that would surely be a wedge too. What's the point of a tapered peg?
I have exhaustively search for a "mechanical phrase" to describe what a "drawbore" actually does...I agree too Sean..drawborn trunnell/pegs...by their overall affect and geometry...are not wedges...as the one I employ are typically square and only sometimes round...both are only tapered about 25mm to 30mm at most.
What is the mechanical effect they do have???
I have seen some (limited) text that use the term "wedge" in relationship to them but considering the "text" this was published in and the authors I don't give it much countenance, as these where "novice articles" about timber framing joints, described by "non" Timberwrights.
One my mentors (Amish) referred to it in broken Dutch to English as a "spring shaft" effect, but I feel that might be to much local vernacular even though it does describe the mechanics of how the peg/trunnel functions once driven home.
So...the best I can come up with for "mechanical force" is in the name itself..."drawn" or "pulled"...by means of offset mechanical action between the planes of to passing members...There has to be a way to shorten that...??..So, perhaps "drawn joint" is simply the best?
Then again...a wedged joint is a "drawn joint" by the..."effect of an inclined plane."
While a trunneled or pegged joint is working as an "offset"...??...shear plane, or cam...It would seem?
A tapered peg is an inclined plane, i.e. wedge, until the taper runs out. When there is no taper, no work is being done, and it is just a means to hold the joint together. Trying to say that it isn't a wedge is just over thinking the situation, and adds unnecessary confusion to a simple concept.
Dave...I agree completely that a "tapered peg" would be an inclined plane...Nevertheless...that is not what 99.9% of the "drawbore" pegged/trunneled joints are in Western timber framing...as the peg/trunnel does not possess and inclined plane for its entire length...
I don't think I (et al) are "over thinking" anything and more curious on accurate nomenclature (in English) for how this joint functions...That was the only goal, perhaps of this short section of the discussion...
Pegs/trunnel are not 'wedges' by any definition of the word or mechanical process...because...the "taper" does not run the length of the peg...ergo...there is no "wedging action of an inclined plane"...except, of course, in only a fraction of the overall length...
Further, there are round and square..."tapered pegs"...or..."pinned joints." These are indeed "wedged pins" but they are neither common nor found in Western framing (that I know of??) and only found in Japanese and other Asian joinery systems...
I don't believe (for the most part) that this is a very confusing concept or description at all? Other than defining more succinctly what other "mechanical process" is taking place in securing a "drawborn" joint.
If there is no taper, then nothing is happening when you drive the peg. Even if the taper is for a short part of the length, that is where the work is getting done. If you tried to drive a pure cylinder through a draw bored joint, you would destroy the tenon relish, not draw the joint tighter.
If your pegs do indeed tapered the entire length...then I would agree completely that besides "drawing" the joint together, your approach to pegging a joint is a combination of a "draw and wedge."
I have seen this (rarely) in some barns, and old frames where pegs that seem to have more tapper from one end to the other. Thus far, this has always been in barns and older timber frames that have either been moved or modified and not the original work.
Further, when a Pe specs a "pegged joint" they will not allow (at least never in my experience) a cross sectional peg less than the full diameter of the hole that receives it. In ever frame I have had to meet there standards on, this is always the case.
Is the joints you are producing this way "strong enough?" I would think most likely they are...Nevertheless, they are not nearly as strong as if they are pegged with a full cross sectional peg, and there is a reasonable amount of academic study on this topic. I would love to see (or read) more PE studies that reflect the contrary and what "strong enough" may actually be in some joint configurations...
As I shared in my last comment we do use...".."tapered pegs"...or..."pinned joints" that is similar to what yours is in one respect...the peg (be it square or round) is tapered from end to end. However, traditionally (and the way we still employ this pinning system)...there is not only more "offset" than typically in the hole for the "tapered peg" (wedged if you will) There are also two of them driven from either side of the joint and driven home till they fully "seat" the hole, or square mortise that receives them...
My theory on this full tapered peg goes something like this, Jay.
When I have used a full sized peg that only has a short taper on the leading point, it has a high risk of blowing out the relish on the back of the peg hole. So I have adopted this longer tapered peg and am very happy with 20 years of use. All my pegs are hand made. Usually red oak. So, in the PE studies do they caculate the relish and the blow out that will happen if the peg is crammed into a drawn hole? Sure they do. You happened to leave out this factor in you strength calculations, it is not just the peg but the relish behind the peg and if that is compromised, the peg is of no use what so ever. By the time the joint is fully drawn and the peg comes to rest the cross section is withing specs of the hole. Also keep in mind there are many joints that are pegged that don't even need pegs, they are only used to wedge the joint together for assembly purposes.
Personally, I thought it was a confusion of terms to refer to a pinned joint as being wedged. There are wedged TF frame joints, and I think that we all know what they are. By the same token, a dovetail joint has a very definite wedging action, but we wound not say it is a wedged joint.
I think that as an overall concept, the majority of pegged joinery really isn't accurately described as wedged.
If there is no taper, then nothing is happening when you drive the peg. Even if the taper is for a short part of the length, that is where the work is getting done....
Sorry Dave...not only does that not make sense to me from an engineering or mechanical perspective it is not true historically in timber frames or furniture that I have read about, seen, restored, or studied...???
"Most"...(virtually all?) pegs/trunnel, be it in a chair, table, door, window...or...timber frame...are typically solid full cylinders (or squares) from end to end (once driven home.)
The..."happening"...is created by the "offset" between the hole (square mortise) in the tenon and that of the hole/mortise in the received member. It is the "offset" that creates the draw, and not the "taper."
...If you tried to drive a pure cylinder through a draw bored joint, you would destroy the tenon relish, not draw the joint tighter.
Sorry again, but if that was the case, I would have destroyed thousands of joints at this point...and I haven't thus far...
Most "turned pegs" and riven...come as full cylinders and only have a slight "coving," "rondel" or "point" on one end that facilitates them properly engaging the "offset" and begins drawing the joint together...That is if the joint hasn't be "podgered" as I suggest is a much better practice...
There is no doubt that..."draw pins" (aka "timber framing "podgers")...be they for furniture or timber frames (we love them!!! and think they are a must have to draw these joints consistently and well...) are tapered for a portion of their length...Again...this is only to facilitate the ease of entry before driven home...it also is to facilitate their extraction once the proper..."draw"...is completed..
The following photos are PE approved pegs...Note that the pegs/trunnel are all full cylinders except for the very end...
Below is typical from a vintage frame that has not been moved and is original in materials and modality of construction...Note that few (if any) of the trunnel are tapered or "wedge shaped." These are full cylinder pegs and commonly found as such in most timber framing cultures whether "round peg/trunnel" or "square pin"...there is no inclined plane...
Classic Draw Pins and/or Podgers and a "offset Pricker"...
Anatomy of a well "drawn" furniture joint, a die plate or "peg shear"...Again the pegs produced are in a full cylindrical geometry...
Personally, I thought it was a confusion of terms to refer to a pinned joint as being wedged....
You are correct Sean, and it is not accurate in description of mechanical action taking place between peg and joint assembly...Except perhaps (as stated) only in the very beginning.
There are wedged TF frame joints, and I think that we all know what they are...
Correct again, and for the clarification of nomenclature (at least in English) when we employ "wedges" in timber frames or furniture...these are typically referred to as... "keyed joints." The action of a "key joint" is a "wedging effect" that effectively and effecently draws the joint very tight, as well as, creates a method of additional tightening in the future and better joint flexiblity...
If any are interest, we can explore this topic as found in Asian timber framing systems as well, and the applicable nomenclature and joint descriptions...
All in all...the reasoning behind your system of pegging makes sense...
I would suggest that it is not the traditional nor standard practice for pegging or pinned joint systems...
"Offset" drawn joints are meant to be "pre loaded and drawn" before the peg or square pin is inserted and driven home.
In absence of a metal "podger"...a well seasoned and hardwood peg (undersized and tapered for 1/3 its length) of a wood species like Dogwood (aka "Dagger Wood") is fire tempered and case hardened. This is used in place of a metal podger or draw pin to "pre-draw" the joint and is driven from one side...and out the other. Then the final peg is driven in.
This would be time to note that pegged and pinned joints should also be wax and lubricated. This in turn diminishes greatly (if not arrests completely) the worry and/or risk..."...of blowing out the relish on the back of the peg hole..."
As suggested before Tim, such "tapered pegs" would not (most likely in many cases) meet PE specifications for a pegged or pinned joint. There is no need to..."calculate the relish and the blowout that will happen if the peg is crammed into a drawn hole..." because a peg or pin should never be "crammed into a draw hole" that isn't pre drawn and well lubricated...Which is a traditional practice in several timber framing cultures.
If your system works for you, and you do not have to meet PE mandates on frames, by all means do as you will. I only suggest that it is an "invented system" and not a standard nor traditional practice in common overall, but indicative of some of the post era and contemporary timber framing methods that have taken place in some areas of timber framing as reflected in relocated old barns and timber frame homes. In that regard, it is in practice...but not the original work.
In reference to your description of "cross section" a peg or pin (per numerous PE I have worked with over the decades suggest) must have a "full diameter" or "cross section from point of entry to exit...not just a portion thereof. So, to be clear, I did not "leave out this factor in...strength," as I understand the mechanics and reasoning behind why modern timber framing PE, and traditional Timberwrights did it the way I have described...more commonly than the method you have suggested and employ. Again, if you like what you do...by all means continue. I only suggest additional insight to the craft and meant no offense.
I also agree that many joints are pegged for the shear sake of raising the frame, and play little within the structural integrity of the joint. This is why (and in some areas quite common) oblique braces are never pegged. Instead they are "wedged" and sometime they are place after raising. Most "brace assembly" lack the proper relish on their tenons to ever have a peg driven through them, nor need it...Just to address one joint that is pegged that shouldn't be nor actually needs it as it works only in compression...
Jay, you really aren't grasping what I'm trying to say, and your excessively long replies do nothing to hide that. Without that small but of taper,rounding, etc., you would never get the peg started without damage. Once you reach the full diameter of the peg, then there is no more draw boring going on.
I find your approach at discussing things very arrogant, as if you are the only intelligent and experienced person in the conversation. You've been booted from at least one forum already for this. I know that you have alienated people from the discussions here because they don't want to endure your verbose replies. Anytime there is a request for information here that someone responds to before you, you seem to feel the need to add a multi paragraphed response as well, which usually runs way off point with your need to discuss the many irrelevant modalities with which you have some experience with. Please don't think I am alone in my opinion, I'm just the first one to get bothered enough to say something.
Dave, some folks say "arrogant" (they typically like to argue and debate" a topic of discussion)...
Other say "informative, helpful and of great value"...(they typically like to learn, discuss and explore a topics many side fully)...
We can only choose which we care to be at any given time...
I can't (nor intend) to appease or placate all that read my posts. I always go back through (often several times) and re-read what someone is "trying" to convey on a topic, as a teacher, that is imperative.
I quoted you on every point I addressed as clearly as I possibly could and illustrated as effectively as possible where able. I do not attempt this to dissuade you by any means. Act and believe as you wish. I write instead when I feel there perhaps is another view, and/or historical/empirical indicator to the contrary, and for the many others that read these forums, post and follow my writing on the subject (I have corresponded positively with several offline on this topic...as apparently not everyone finds my post "arrogant.)
Again, I do sincerely apologize if I have inadvertently offended you in some fashion...that is not my intent. I will and do have the same "conditional rights" as everyone else on this forum to post however way I wish as long as I am courteous and respectful. Which does not mean we have to agree with one another. If you don't agree with me, I am o.k. with that...No hard feelings there at all...
We can consider that the opposite of arrogance is humility. A humble response would be to say that perhaps there is room for improvement, and to look for the truth in what Dave is saying, even if the majority of his argument were invalid. You call yourself a teacher, a true teacher must realize that he never stops being a student, and must never consider himself to be above his pupils or in any way superior.
In the eyes of many, your response will only strengthen Dave's point.
In Dave's defense, his point is correct. When we apply a taper on the end of a peg, even if it is slight, we are assuming that peg will exert a wedging force for the length of that taper (even if it were only a bevel) In the case of non drawing pegs, that wedging force only serves to ease in initial insertion of the peg. It may not be absolutely necessary, but it still does perform that action.
In the case of a draw-born hole, you have a much longer taper on the end of the peg (around here, pegs tended to be sharpened nearly to a point with a taper 3 to 4 inches long). Draw born holes are not lined up, essentially meaning you have a smaller hole in which to insert the end of your peg. As you drive it in, the inclined surface of the peg forces the tow unaligned holes into alignment with each other. The longer the taper, the easier this action is. This is by definition a wedging force.
There is an analogue in Central Europe that can be used to illustrate this point further. On the sills of large timber frames, double or triple through tenons are used, secured in place with wooden wedges. Both German and English refer to these as wedges, although in service a flat portion is in the joint. The wedging action occurs only during assembly. They have a taper on the end, after which they flatten out. They wedged ends serve to draw the sill beams together, and the flat surface prevents them from working their way out of the joint over time. I've never heard these referred to as anything other than wedges, and the joint is called a wedged joint. It is exactly the same action being performed by a draw peg. The wedging force acts during assembly, after which it is no longer necessary. It is no matter whether the wedging is performed by the in service peg (which around here would often be trimmed off, removing the pointed end) or by a steel peg or other assembly tool which is then removed and replaced. The force at work is still a wedging force.
Loc: the Netherlands
I can't say that rational for using pegs tapered in the whole length is convincing. And wedging like that is something I never trusted with the natural movement of wood let alone shifting and shaking in a timber frame. I even avoided till now those tapered plug cutters put out as so innovative by Veritas and stick with straight sided plugs.
Cecile, have you ever under cut something so the leading edge will be tight, making for a clean looking job, especially when attention to details is not totally needed? Pegs are this way, more than not. There are different people out there and we all interact in differing ways. I don't know what you fellows that don't understand the tapered peg are seeing but it clearly is not what I am seeing. There is now way I will ever change my pegging style, it is a beautiful thing. I have to ask if those that use full length size pegs are truly draw boring? Those draws vary in amounts of draw. How do you manage a tight draw? Do you thin out the full size peg or just crush it into the hole?
For the general part of it all Tim...and in the frames I have followed your work on...I think (I could be wrong without understanding more details) that your method is fine and does probably serve you well. I believe it was also you that brought up "redundancy" here or someplace else and I agree with that also so the peg size isn't the "most critical" element collectively on a frame though still very important.
I am curious, it the accumulative cross section of a member assembly is say 200 mm (8")...what percentage of that is full peg and what still has tapper after being driven home?
To your questions (speaking from my own experience and understanding of its methods):
...those that use full length size pegs are truly draw boring?
By all major principals of the method as I know it...They are "drawn" as I understand the method. I am a "green woodworker" fan of the Jennie Alexander, Roy Underhill, Peter Follansbee ilk, so be it riven green oak, hickory, ash, pine etc for a Trestle table, cabinet or "knockdown" Armoire to a timber frame...I like my wood "green" and draw boring does well with these systems. The holes are offset accordingly and the joint "undercut" often as you rightfully suggest to achieve the tight fit these combined methods yield when working well in concert with one another...
...Those draws vary in amounts of draw. How do you manage a tight draw?
I could be missing it on this one...?? but from the layout systems I use and the approaches I take to this there isn't much variation, unless I am understanding this question incorrectly? We manage a very tight draw because of the draw pin or podgers.
Do you thin out the full size peg or just crush it into the hole?
It usually crushes the ingress point and fully fills the egress area with some crushing there as well in some species. I do also like octagonal or hexagonal riven pegs the best, and much more than turned pegs...if too dried out both will get oil soaked, and these days I am really liking the canola oil as it isn't a "drying oil," and the pegs stay strong yet suppel...
If the timber is 8" wide, the joinery is typically 2" off the reference face with 1.5 or 2" mortice. So one side only has 2" of decent full peg on one side the other side, the off side, will see at least another equal 2" of good meat. Plenty in my book. The extra 4" on the far side will yield some peg length allow the flex in the peg that is desirable and of which you speak of, Jay. So all that and no damage to the relish on the tenon.
I do not think that anyone will argue that there is no wedging force happening in a draw-bored joint. However, I think that the distinction being made is that a pegged joint is not a true wedged joint. Typically in my mind, a wedged joint has a continuous plane which can be adjusted through a range.
I agree with Timbeal that what he uses might be considered more of a wedged joint , it's sort of a hybrid. I don't really think that it is representative of pegging practice overall.
I don't want to make a big point of this, but I really enjoy Jay's posts whether I agree or not. I can see that he pushes people's buttons sometimes, but I don't think it is intentional. I think that he has strongly held opinions which he is not afraid to state vociferously, just like the rest of us! I actually miss his input quite a bit on the Forestry Forum, it livened things up and created some good heated debate! Lets enjoy the debate and not take it personally. En Garde!
Personally, I use a riven octagonal peg tapered only on the last 1" or 1 1/2". I do soak them in a bucket of linseed oil and find that it makes driving them much easier. Personally, I don't see an issue with a small amount of crushing on the relish side of a draw-bored hole. I think it's unavoidable with an offset hole.
I think that the point with the peg not filling the entire hole is that it makes it a bit of an engineering unknown. Which is really not a major problem for many projects, but can be problematic if dealing with trusses or heavily loaded beams in tension.
Just a reminder why I started this thread. I am boring round holes on through tenons, they are not chiseled square. I am then inserting half round tapered wedges into these wedge holes, this happens on the opposite side of the tie beam. All in replacement of a rectangular tapered wedge. My contention is it is no different than a draw bored peg.
Well, that last comment does clarify things or narrows the contention, so that's helpful. You would have to go even further though to be convincing on that last sentence, something like, "...when the outer side of the tenon hole has a corresponding angle to the bearing side of the wedge inserted..." for example, and even then it's an up-hill argument. You wrote earlier the wedges are 1:8 a standard ratio of slope for a dovetail joint so I guess the hole that wedge fits also has a corresponding slope or something comparable for an equal dispersion of the pressure drawing the tenon in, otherwise I now understand the likelihood of blowout you fear.
Yes Mr Wagstaff. It was a daunting task, we managed to apply a shim, a wedge in itself, to one side of the boring machine to get the hole tilted. If using a T-auger one could simply tilt it away a bit and be near perfect in the slope. I am not fearing the blow out as I take precautions against it, once we recognize the fear we can embrace it.
You see, the fog of a murky proposition starts to thin and clear thinking can then begin to settle in. It also addresses my next question, preemptively, about the different sized exposed ends of these "tapered pegs" or what I am now calling the Beal effect.