Anyone tried this: Peening your tenons

[Frederick Skelly]

Current FWW has a full page shop tip on doing this (FWW #263, page 12). Basically, you cut a snug tenon, pound the tenon's faces gently to compress them and then put glue on it and slip it into the mortise. The author said it's a Japanese technique.

Thoughts?
Fred

[Jim Koepke]

For a moment my response was going to be about how Chris Schwarz did something like this to help fill gaps in dovetails.

The technique you mention is more akin to planishing than peening. Both are metal working terms that are making their way in to woodworking

jtk

[Brian Holcombe]

Very commonly practiced in boat building amongst other things.

[Malcolm Schweizer]

Am I the only one that at first thought this said "Peeing in your tenons"? I thought, "Okay, I'm all for unplugged, but that's taking it a bit too far." Dyslexia can be funny sometimes.

[lowell holmes]

I would be more likely to plane translucent shavings until the tenon fit.

[Pat Barry]

I think the idea behind this is to get a tighter fit after the temporary wood fiber compression from the peening takes place. The moisture in the glue will expedite this (like biscuits swelling up).

[Brian Holcombe]

The point is not to make the tenon fit, it is to compress the tenon so that when it swells back up it locks the assembly together. Don't go overboard and it works fine.

Pat beat me to it*

[Scott Pearson]

I have read that it used in Japanese joinery with a Japanese hammer. The purpose is to compress the tenon to fit the mortise snugly and then allow the tenon to swell from the moisture of the glue for a tighter fit. The reason for the Japanese hammer is that one face of the hammer is 'crowned' not round like a ball peen. The crown compresses the wood without cutting the fibers. A flat faced hammer will cut the fibers of the wood and stop or reduce the wood fibers from swelling. A ball peen hammer would just create divots and dents and would not spread over the whole face of the tenon.

I have not used this technique so I have no experience but it seems like it could be a workable technique to get a solid tenon.

Scott

[Simon MacGowen]

Such a method is ok for anyone who has yet to develop his or her hand skills. Or someone who is mainly a power tool user. It is not something I will do or recommend to anyone who is seriously interested in developing traditional skills. Same thing I cringe when I see someone use a file to fine tune a mortise & tenon joint or even a dovetail (oh yes, I have seen that in magazine articles).

As a top tip winner, it does not have a place in a publication like FWW. Fine if I saw it in Woodsmith or something like that. May be next time someone would win a top prize from FWW by suggesting using a sledge hammer instead of a plane to remove a high spot on a board.

By the way, don't know if it is indeed a Japanese technique but I have seen anything like that in any publications or videos. Everything I have seen by Japanese woodworkers is fine tuning with a chisel or plane.

Simon

[Warren Weckesser]

Skip to about 4:35 to see an example of this applied to butterfly keys: https://www.youtube.com/watch?v=x51zMg7roIs&t=310s

[Simon MacGowen]

Thanks for the link. I have seen hammering in other contexts (by non-Japanese woodworkers) but not the compressing in a vise. When I do wedging (mortise & tenon), I sometimes hammer the wedges (sides or tip) for a supertight fit.

Simon

[Brian Holcombe]

Who is crimping them in a vise? Again this is a common technique, often applied to softwoods, I believe it does a disservice to hardwoods.

[Simon MacGowen]

Who is crimping them in a vise? Again this is a common technique, often applied to softwoods, I believe it does a disservice to hardwoods.

Are we talking about the same tip?

In the second illustration with this caption: "Use a vise to compress..."

My objection to the tip -- whether it is a Japanese technique or not -- is that FWW should promote it as a tip but not as the Best Tip. If one has no access to a fine shoulder plane or chisel or a router (Paul Sellers' preferred approach), that is a way of finetuning a mortise and tenon joint. But to anyone looking to develop fine traditional skills, I will steer them away from it, and would never look at it as a best tip.

Simon

[Brian Holcombe]

Don't use it then, but it's not being used becuase the user doesn't know any better, it's being applied in a purposeful manner when done correctly.

It is a traditional technique in fact I had been studying Japanese bathtubs recently and the technique is applied very purposefully to their construction. They don't need to caulk the joints becuase of this.

[Simon MacGowen]

Not meant to be putting down any techniques of any other cultures (we all can learn from each other) with my objection and I use Japanese saws and chisels when the occasions call for them.

Not very tip I see in FWW or any other magazines is adopted or used unreservedly in my shop. Some are lousy ideas for me though they may be smart solutions for others (including the Editors who publish them). Like anything else, we each have to decide for ourselves our ways of doing things. I, for one, rarely use softwood, but even if I use it, the vise in my shop or a file will not be put to use for fine tuning any joint.

Simon