Wedged through tenons question

Re: Wedged through tenons question

Jim in Burlington Ontario

>If the spruce is still wet it's going to crush pretty easily so only a small bevel is needed. Any hardwood works well for wedges but I'd use something other than oak if the spruce is wet it might discolor badly and bleed.

Kinda reminds me of a

Frank Mutchler in Colorado Springs

>dovetail. Is that the purpose of a wedged tenon? I was thinking about drawboring/fox-wedging/wedging, etc. today and I came to the conclusion that, given the quality of todays adhesives, those joints are not necessary. Perhaps some of them provide cosmetic affects that justify the extra work??

Re: Kinda reminds me of a

Adam Cherubini, NJ

>I disagree about the adhesives. Hide glue or epoxy are the only adhesives that make sense for these joints. With epoxy you really have to tape the joint off to keep the epoxy from running out.

I agree that I don't get the sense of wedging, foxed tailed or otherwise.

If you want a structural M&T, draw boring is the way to go. Wedging is not the same. With this material you may be better off as Frank has said either gluing or draw boring then wedging for cosmetics.

Adam

Re: Wedged through tenons question

Richard Gillespie

>Dave, in response to your question, I don't think I'd taper the mortise at all. The only two times I've ever attempted those joints were in two hardwood bookcases. In both cases, I used too much taper and had to fill the gaps.

With spruce, it's soft enough that the wood will slightly crush and lock. I'd use black walnut as the wedges though.

Agree...

David Miller from Iowa

>...with Richard (although I'd be interested in the rationale for wedge selection). I had a lot of trouble with splitting (which I think would be worse in spruce) when I tried to make the mortise wedged shaped or tried to taper the tenons (different pieces). I've had good luck with standard M&Ts, Elmer's glue, and wedges.

One thing though, which may be moot if you already have the stock) I've found wedges work best when they are put in parallel to the rays.

Re: Wedged through tenons question

Raymond in Trenton NJ

>Hi Dave,

Sorry, this ended up being longer than I intended.

I've never done this so take it for what it's worth ... two cents. There have been a couple of articles in FWW (and other places) that discuss the angles you're asking about, but more on that later. Honoring your �Don�t ask� statement and the fact that it�s construction grade wood I can imagine a plethora of possibilities (including a finely finished piece). In the absence of any helpful information or useful data (don�t worry, my job requires me to do this all the time :o) so here goes.

I agree with Frank and Adam that drawboring is the way to go for strength (vs wedging). Keep in mind that even with the 3� side, you don�t have a lot of material to work with, you�d have to be mindful on peg size and placement. So if choosing to use a wedged joint was not part of the aesthetics of the finished joint, I�d drawbore, or conventionally pin it.

Everything I�ve seen and read on wedging was related to the use of hardwoods (I think). There were always two wedges and they were near the tenon ends. One precise method is to make test strips (same material) and bend them to determine how thick to make the �thin pieces of tenon� without breaking them when wedging. Also angling the mortise to the same wedge angle. I think there were several FWW articles about this.

The other extreme is to a straight M&T and saw �about that far� from the each end of the tenon, make wedges (by eye) and bang them in at glue up. That�s what I did on my ... er LOML�s step stool. Just make sure that the wedges don�t bottom out in the kerf. With a softwood, you could probably do without any clearance in the length of the mortise (the direction of wedging). Any hardwood will do for wedges.

Happy building! Wait, I know, you�re building a derrick to move raw lumber from the top slope of your �lower forty� completely over SWMBO�s flower beds, right? I knoew you�d figure it out Dave, way to go. :o)

Raymond

hoping to see you Wednesday (10/27) in Springfield VA

Re: Wedged through tenons question

Dave (Arlington, VA)

>Hi Jim -

Thanks for your post. I had forgotten about how easily spruce's fibers crush. That's a great point, and I'll keep it in mind if I go with the wedged tenons vs. the drawboring (as others have recommended) because it would make a difference.

I'm going to make another post below and you'll see that aesthetics are not a major concerns here, but nonetheless thanks for the warning on red oak stains.

Again, thanks!

Dave

Re: Kinda reminds me of a

Dave (Arlington, VA)

>Thanks, Frank -

Yes, it would be somewhat like a dovetail - at least to my understanding. Also I'm not sure (as with Adam) that glue will hold up under all circumstances (including the one that I intend).

I am sure that aesthetics could be a factor in deciding to use a wedged tenon, but it's not one of my considerations. Also on "fox tail" tenons it would also not be a factor since, if I understand it correctly, they are hidden.

Thanks for your post.

Regards -

Dave

Re: Kinda reminds me of a

Dave (Arlington, VA)

>Hi Adam -

Thank you for your comments. I share your doubts about the value of adhesives under some circumstances.

I had given drawboring and/or pinning some thought but had doubts about that I will explain in another, fuller post below.

On a wedged tenon - it seems to me with wedges and the relief of the ends of the mortise that you in effect create an internal dovetail joint, and this would seem to me to add substantially to the mechanical holding power of a joint. I must be missing something here.

Again, thank you. I always enjoy your posts.

Regards -

Dave

Re: Wedged through tenons question

Dave (Arlington, VA)

>Richards -

Thanks for your comments. I had forgotten that spruce was that soft, and it's good to hear of your experience. I'm sure that your piece looked just fine even with the "filling." Though I wasn't thinking of doing a wedged tenon here for aesthetic reasons, I think they look cool.

Also walnut would be a nice contrast.

Again, thanks!

Regards -

Dave

Re: Agree...

Dave (Arlington, VA)

>Hi David -

Thanks for your post.

I had wondered about splitting - so thanks for those comments. One thing I was thinking about doing was drilling a smallish "stop" hole at the end of the slot for the wedge to reduce the stresses as the wedge is driven in place.

Again, many thanks for your reply.

Regards -

Dave

Re: Wedged through tenons question *LINK*

Scott in Douglassville, PA

>Hey, Dave -

Might want to look at this thread - some info, and background on others' opinions on suitablity of this joint in practice.

I've done a few dozen of these no; email me if you want some particulars.

Scott


Wedged M&Ts - tapered mortises or not?

Re: Wedged through tenons question

Dave (Arlington, VA)

>Hi Ray -

Good to hear from you. Thanks for the post.

Wedged tenons vs. drawboring. Hmmm. I'm going to have to give this some more thought.

On the wedged tenons, I was planning on using two wedges in each tenon - as you did on your step stool. As far as FWW is concerned, I can't recall any such articles, but I'll search when I get off work this evening. Thanks for the heads up.

Sorry, no derricks here. And I still haven't come up with a satisfactory way to get that wood down from the back of our property without destroying my wifes flower beds and garden.

As for the "lower forty" reference, you can be sure that if I owned forty acres here in Arlington I wouldn't doing my own framing for an A/C conduit!!!! - see the post below.

In any case, thanks for your post. I hope I can make the galoot get together next week. I'll certainly try.

Regards -

Dave

True confessions....

Dave (Arlington, VA)

>Hi All ----

What I am building is not furniture. Boy, this is embarrassing. I am building a wooden frame (i.e. construction grade 2x3 spruce) around which I will affix sheetrock to enclose an 4� air conditioning conduit that extends from the middle of our kitchen to and through the adjacent wall in order to provide air conditioning to the dining room (it�s an early 1960s house and the A/C was added after the house of was built).

Initially I had just planned to use metal �L� brackets and screws to hold this thing together so that it would not come crashing down on us during a meal � since we take most of our meals in the kitchen. But then I thought � (perhaps a bad idea?) that this could be a good opportunity to practice my mortise and tenon skills�which are pretty much non-existent. You know: skill development.

Then I began to think of what would happen if the glue joint failed � especially those holding the vertical elements of the frame. That�s when I began to think about mechanical ways to strengthen the joint. I had thought about drawboring, or pinning, but it to me it seemed to me (what do I know?) that a wedged tenon would provide superior mechanical support. In any case, as you can see, aesthetics are not a factor here � only strength.

Another concern (relevant or not) that I had about drawboring and pinning was that 6 of the 8 corners of the wooden frame would have to have two mortise and tenon joints in each corner, and I was unsure if there would be enough �meat� left in the mortised pieces to do the job.

Now with this confession off my chest, I don�t know if anyone else has any other thoughts on this. In my own defense (since I am feeling somewhat defensive about this) I do have a kitchen table on my list of impending projects as well as a bathroom vanity (yes, Ray � I haven�t gotten to it yet, and it�s still on the list!), and they will require some M&Ts, so I thought this might give me some useful practice.

In any case, thank you all for the advice and insights. I very much appreciate it.

Regards �

Dave

Re: Wedged through tenons question

Dave (Arlington, VA)

>Hi Scott -

That's great. I absolutely did not remember that thread. I haven't had a chance to get through it yet, but I am looking forward to tackling it this evening. Looks like a great resource, and I'm sorry to rehash this.

Again, thanks!

Regards -

Dave

Adam, thanks to Scott's link below...

Dave (Arlington, VA)

>Hi Adam -

I had a few minutes to go back and read the thread on wedged tenons from this past July - thanks to Scott's link. I hadn't remembered that discussion when I posted my question. Anyway, now I've had a chance to look over your earlier comments, and have a better understanding of your thinking on this subject.

Thanks -

Dave

Re: True confessions....

Jack Guzman from Maine

>Dave,for what you are building I would use screws and predrill where the ends of the wood may split.This is carpentry,plain and simple,cabinet joints are overkill.Practice your jointery on projects for the shop in hardwood.---Jack

Re: True confessions....

Dave (Arlington, VA)

>Hi Jack -

I appreciate your perspective - and there's no doubt this is carpentry, not cabinentmaking. Your suggestion was my Plan A, and it would certainly have my wife's full support. My thought was that I could kill two birds with one stone: I could work on a project on "The List" while getting in a little hand tool skill development in the process.

Thanks for your thoughts.

Regards -

Dave

Re: True confessions....

Joe Rogers, Northern Virginia

>Dave...How about a hybrid construction plan. Use the available "easy" joints to practice the joinery on and where there is a conflict in the joint relating to complicated angles or number of elements just use a simple carpentry joint or even a hanger plate or mending plate. That way your construction isn't compromised strength wise but you still get the skill building exercise.

Seems like the best option...I would even consider multiple joints just to experience the effort. Pin one wedge one... Just a thought.

Will it be clad in drywall ultimately? JR

Re: True confessions....

Don Thompson - Cutler Ridge, Florida

>Me too. I have practiced a bunch of new (for me at the time) joinery techniques on benches for plants in the yard, shelves for the utility room, racks for the wife's orchids, etc. Cheap practice, nobody cares about a little tear-out, etc., and I get some useful progress on the honey-do list. Did the same thing with finishes. (none of the pantry shelves match!)

Re: True confessions....

Dave (Arlington, VA)

>Hi Joe -

Thanks for your comments. As always, they are helpful. I had hoped to get to this project this weekend, but too many soccer games, kids birthday parties and so forth. I am reconsidering my options and may go with so kind of "compromise" as you suggest. We'll see.

Again thanks for sharing your thoughts.

Dave

Re: True confessions....

Dave (Arlington, VA)

>Hi Don -

Thanks - those are encouraging words. I'm sure that someone who has chopped out even a half dozen (or more) mortises in hard wood would wonder why anyone would try something like this in spruce, and on a DIY carpentry project. But it seemed to me that for a person (like me) who hasn't chopped a single "real" mortice and is looking at a "must-be-done" project (that won't be seen) that this would be a great time to practice layout, chopping and sawing technique, dry fitting and so forth.

So, I appreciate your kind works and your taking the time to post. Thanks.

Dave