Chair leg

[campbellcraft]

I need to replace a broken chair leg. Broken leg was sawn off leaving a 1 3/4 square. Carvex cut it square and smooth. The question is what size/number of Dominos would give me the greatest strength. At the joint the replacement leg will be 1 3/4 also.

 

[Birdhunter]

If it were my chair, I would not rely on a Domino joint. I'd drill well into both ends and glue in a steel rod at least 3/8" in diameter and at least 6" long. You can get some very large shear forces on a chair leg if a heavy person slides the chair while putting weight on it.

 

[gkaiseril]

Consider metal screw dowels used for balusters.  Baluster Fasting kit with driver

It might be best to replace the leg.

 

[campbellcraft]

Birdhunter
You have hit on my concern. The max hole would be 3 1/2 into the chair and 4 1/2 into the new leg. The diameter of the steel rod could easily go to 1/2 (or more). Any opinion on these dimensions?  Thanks.

 

[campbellcraft]

I like the idea of the metal screw dowels but.......1/4x2 seems (I certainly don't know) less strong than a 3/8 or 1/2 rod.
Thanks

 

[gkaiseril]

The dowel screw is screwed into the wood and could even be covered with glue or epoxy. This might be a stronger bond then a metal rod epoxyed into the wood.

You could always use some scarp wood to  see how strong the joints are before trying it on the leg.

I would be concerned about sides of the leg blowing out.

 

[mouppe]

I would cut it off where it meets the seat and replace the whole leg. You will have more area to mortise into and the joint will be stronger.

 

[Birdhunter]

First choice... Replace chair. Second choice...Replace leg. Third choice...Steel rod 1/2" diameter 6" long. I'd be very cautious as a broken chair leg with someone in the chair is a scary proposition. Could lead to a major injury.

 

[jacko9]

If you have the DF700 Domino Joiner, I would step the joint and cut in a pair of 14mm Dominos using Titebond III glue.  With a stepped joint, you'll have a long grain to long grain glue joint as well as a double M&T joint.  Depending on the finishing schedule, you might be able to partially conceal the joint.  You can also just build a new chair and engineer the design not to fail like the last chair.

Jack