This Might be One needing talked about -- Oak chair loose wood joints

[baileyuph]

Oak kitchen type chair, long time user says leg rung joints have been difficult to keep tight.

One tech drilled and added a screw (4 joints).

One question that came to mind:  Are all wood joints stronger than same joints (rungs) with a screw drilled and installed.

Other things that come to mind are:

1.  Glue used

2.  calibration of rung to hole (sloppy fit?)

3.  Instead of the screw - use a smaller dowel to lock a joint.

This issue came up - customer called wanting to bring chair in for a review, so haven't seen it yet.

Reasonable to assume the chair(s) are in a climate controlled room.

Looking for whatever tips - chair(s) will probably be brought in within couple days.

Doyle.

[byhammerandhand]

I do not like screws in chair rung joints. 

My takes on this:
* They keep the joint from coming apart, but they don't keep it from coming loose.
* It concentrates the stress on a small area
* If the joint breaks, it breaks at the screw hole

The only thing worse is a pneumatic nail in the joint (or five or six).   It's nearly impossible to get them out without causing damage.   Though some times you can twist the rung and it will wrap the brad around and get it out.

"There is a special room in Hell for people that put nails in screw joints.   And it's right next door to the room for people that put screws in chair joints."

One of the first things I learned about woodworking is that dowel joints are destined to fail.  It just happens to deal with the physics of wood movement (technically known as orthotropic, which, if you look up in the dictionary, usually talks about wood as a prime example).   Two pieces of wood moving in different axes in different amounts.   But on chairs, we're dealt this hand.  I did have a week-long chair class back in the '80s using a "wet-dry" joinery technique.  It's the only type of joint of this kind that deals with this. ("Make a Chair  from a Tree")

A friend of mine says there are two types of chairs, those with loose joints and those that will someday have loose joints.

Take it apart, clean out the joints, re-glue, adding some wood if needed, and make it good for a few more years.

http://www.popularwoodworking.com/article/the_best_way_to_reglue_furniture1

http://www.popularwoodworking.com/techniques/finishing/regluing_doweled_chairs

http://www.finewoodworking.com/how-to/article/the-dowel-joint.aspx

[baileyuph]

Hammer big thanks for the share of this information.  Turns out exactly what you say is what my gut believed. 

Can I get you to go into the "adding wood"?  I guess you are covering the cases where the precision of fit, that is say a rung and another rung, or more likely a rung with a leg are worn to a poor fit. 

In the latter example, what I have done is add wood to either one that is easiest and then turn the piece down on a cutter (lathe or?).

My experience with glues are - if professional glue- they are all good.

Thanks again,

Doyle

[SteveA]

As Keith says - all good information.  Read up on Windsor chair construction - very interesting although something not done in repair work.
SA

[byhammerandhand]

I know a lot of people use epoxy as a gap-filling glue.   I have done it, but only when I figure this is the last time it will need to be repaired (beat to death restaurant chairs).  I prefer to make it reversible or re-repairable down the line.   I've had too many overzealous repairs that didn't hold then it was a mess to repair over an inappropriate repair (generally following a "My husband tried to fix this with Gorilla Glue and...").

I generally use Titebond or a white PVA glue (longer closed assembly time), or for a true antique, hide glue, if that was what was originally used.

For gaps, I fill with veneer or plane shavings, and that's usually enough.

BTW, I hate Gorilla Glue.   I've even done work for the owners of the company.   Their type-II PVA glue is fine, as long as you don't get it on your cloths or other fabric, but the polyurethane glue is a mess.  Cures in the bottle, stains your fingers, foams out, can push joints apart, and has absolutely zero gap filling strength.  And it's a mess if you have to clean up and reglue as nothing dissolves it.