should I microwave my pegs?

Re: should I microwave my pegs?

Thom D


>I wouldn't bother. I would just want them at the same moisture content,so that they don't blow anything up when they normalize. Draw bores are an interesting situation since they are heavily loaded from one side due to the offset. It isn't like a mortise where the tightness of the overall circumference dictates success. Getting them to stay tight on the surfaces hasn't been a problem for me. A little drier moisture in the peg probably won't hurt much either. I'd spend more time getting the grain oriented for max compression resistance.

Re: should I microwave my pegs?

charles


>You need to cleave (rive) your pegs off a small block of straight grained wood using a pocket knife and a rawhide mallet. The you whittle them round on the bottom and leave them rectangular at the top which wedges better in a round hole.

You don't need to buy dowel stock and you sure as heck don't need a dowel plate for making pegs.

Re: should I microwave my pegs?

Pam Niedermayer - Austin, TX


>I think it's much faster to use a somewhat dullish chisel and hammer/mallet for this job. Of course, that could speak more to my pitiful excuse for a pocket knife.

And you can continue to use a chisel, a wide one, for all the shaping, just keep camphering the edges until you get to something close to round.

Off-the-shelf dowels are notoriously short grained, not suitable for pegs.

Pam

Why peg a M&T?

bill tindall


>I have never understood the need for pegs. Are they some artifact left over from a time when different adhesives, woods(wet), or techniques were used? Other than a substitute for clamps, which the ancients didn't seem to own (judging from shop inventory), I don't see how they strengthen a well made joint (see M&T joint data in Articles). Seems they just keep a failed joint from falling apart.

They are not without their disadvantages. I would rather repair a M&T that was not pegged (or nailed). And the fact that they keep a M&T together after the adhesive has failed means the joint then becomes subject to joint destroying stresses as the repair is delayed by the failed joint owner.

Re: Why peg a M&T?

Dave Thompson


>Hi Bill,

Personally, I peg my M&T joints more often than I think probably necessary because I like what it adds aesthetically. But, I also like to err on over engineer rather than under engineer. In the case of bridal joints, they are missing a mortise side, so the peg serves to additionally hold for the missing side.

Whether or not pegged joints are necessary with today's modern glues, I think is a fair question, though there are so many additional varying pre-conditions that I think generalizing an answer might be problematic. A workbench and a wall hanging cabinet have different forces acting on them. A large M&T joint is subject to more expansion & shrinkage forces than a small one.

Mortise and tenons have different grain direction, and since moisture expansion/shrinking varies by grain direction, a perfect fit M&T joint is only ever a temporal thing. If racking is applied during the end of the dry season, while things are loose, compression may occur on the ends of tenons and on the cheeks. The compression will be worse and more damage will occur as the tenon gets worked out. A peg would prevent the tenon from slipping out during this loose period and keep it from getting worse.

enjoy,

Dave

Re: Why peg a M&T? *LINK*

Pam Niedermayer - Austin, TX


>If you use a drawbore pin and offset the holes slightly, you tighten the joint and, it seems to me, it's tighter than any clamp would make it, no external marks or indentations (although these would be minimal and probably self-healing). This tightness should help the joint last longer, given that there'd be little if any racking.

Secondly, I find a lot of satisfaction in not having to use glue.

You may want to review John Alexander's pages.

Pam


Alexander on draw bored M&T

Re: Why peg a M&T?

Todd Stock


>I doubt there is a difference in a well fitted joint, where shoulder clearance is routinely very tight. Unless you glue the shoulder, a decent fit should be measured in ten thous (.005 is the width of a well-clamped glue line).

I do think you are on the right track when it comes to preloading the joint to remain together once the glue fails. In a pinned joint where the hole is made after assembly, the pin and tenon will compress and allow some movement, while an offset (drawbored) joint will have already suffered considerable fiber compression and localized failure on the pin and tenon, so allowing a little less movement...almost like a preload.

Re: Why peg a M&T?

Warren in Lancaster, Pa


>I think the pegs in mortise and tenon joints have saved many joints from clumsy repairmen who would otherwise use nails or yellow glue or worse. I've heard people say they use epoxy so "it'll never come apart". Many repair jobs require disassembly of parts and the use of such glues can turn a routine repair into a nightmare for the next guy who has to repair the piece.

Re: should I microwave my pegs?

charlesstanford


>I've always used a pretty nice-sized jack knife as it allowed me to rive off a nice size chunk that was good for several pegs - way more than you'd get with a one or one and a half inch chisel. But certainly your method will work.

Engineer needed...

bill tindall


>Suppose we have a typical M&T joint 1.5 " x 1.5" for a glued area of 2.25 sq in. And we place two 0.25" pins in the joint for an area of 2 x 0.05 sq in. In a pinned joint one is trading 0.10 of parallel to grain strength for 0.10 of perpendicular to grain strength in a 2.25 sq in total surface. I don't see how this pidly amount of material can have any significant effect on the cured joint strength.

Re: Why peg a M&T?

William Duffield, on the Cohansey


>Epoxy is more reversible than aliphatic resin glues. You only need to heat typical epoxies to about 200�F to get them to release.

Re: Why peg a M&T?

Darrell in Oakville


>Our recent guest speaker at the HFMS restores old homes. He spoke about M&T joinery a bit, most especially wrt doors and windows. He said he never found evidence of glue or drawboring in any of the pre-1860 vintage doors & windows he has repaired. They're easy to fix because you knock out the pegs, pull the frame apart and proceed with repairs. Then it all goes back together with new pegs for the next 150 years.

I wonder if lack of glue and plain peg job may be a regional thing (Niagara peninsula).

Darrell

Wood Hoarder, Blade Sharpener, and Occasional Tool User

aesthetics

Tom Sontag - St. Louis


>My rived and chiselled pegs always seem to look crappy up close in the hole. So I decided to use carefully chosen sawn or rived stock and a dowel plate to make round pegs. It wasn't for expediency that I made the choice.

Surely you don't ...

Paul Kierstead


>advocate a strictly utilitarian approach to woodworking? Perhaps the OP *likes* to peg his joints.

Re: Engineer needed...

Dave Thompson


>I'm guessing from the question that the time frame you're thinking about may not be the same nor the constancy of the environment. I'm not confident that glue and the fiber it binds to are going to hold their integrity the same as soon after curing. By not having the peg, one is dependent on the glue bond holding for the life of the piece. If one puts a peg in, then one is dependent on the wood integrity holding, the glue is a bonus.

Regardless, in a not-so-clear example as this, my opinion is aesthetics trump, and beauty is in the eye of the beholder.

enjoy,

Dave

Re: Engineer needed...

Todd Stock


>The pin is loaded in shear, so it's not a 1:1 mapping. I can't imagine any properly sized pin failing before the tenon or the mortise walls suffer failures, while a couple of percent increase in face grain gluing area gained without pinning a loaded joint is not going to make much of a difference.

Pretty academic, though...you are trading a small amount of face grain holding power for the ability to keep the joint together after glue line failure, or in larger projects (barns, homes, bridges), the ability to draw the shoulders tight without having to deal with the potential for distortion from a couple of come-alongs. Not an issue with most furniture, but you never know when you might pick up a commission from one of Paul Bunyon's kin.

that I will buy....

bill tindall


>looks and keeping a failed joint together are unarguable. It is the strength argument that I find questionable.

Re: Engineer needed...

William Duffield, on the Cohansey


>dependent on the glue bond holding for the life of the piece

If you use hot hide glue, as the masters used to good effect in the late 18th and early 19th Centuries, you are only dependent on finding someone to competently repair the piece when the glue bond eventually fails, thus significantly extending its life. When that will be depends on the precision of the joinery and the climatic stresses the piece endures in the next few generations. Of course, most pieces fail due to other causes, e.g., abuse, fire, natural disaster, ugly, failure to pass on ones values to ones decendents, failure to maintain the finish, etc.. Pegged M&Ts won't save your piece in those cases. If the joint is accidentally damaged, the peg will increase the damage and only make the repair more difficult. It can also increase the probability of damage, by hiding the symptoms of a failed glue joint, until trauma causes the joint to fail catastrophically.

The OP made no strength (of M&T at least) argument

Paul Kierstead