Rocker Joint Problem...

[Derek Arita]

First let say thank you for all the help you folks have given me with my first rocker. Sorry you have to be with me every step of the way. Now, I have an issue with the joint between the rocker and the chair legs. The plans called out for a screw and some glue for the joint. Thing is, its an end grain to long grain joint and seems pretty weak to me, with only a single screw holding it in place. After all, with all the flexing and force that joint is going to be subjected to, I can see the glue joint coming loose and only the screw holding it in place.
So, here's what I'm thinking... drill out the screw hole and replace the screw with a dowel, glued in place. That would create a lot more long grain holding power and hopefully, keep the joint from moving. The rocker width is 1.5", so I thinking a .5" dowel would work. What do you think? Will this work?

[glenn bradley]

Dowels have very little face grain glue surface. I would use a tenon although Sam Maloof's graceful rockers use 1/2" dowels IIRC. You can find tests online that show a tenon has about twice the strength of dowels but, these tests have many variations like size, quantity of dowels and material used.

[Derek Arita]

Dowels have very little face grain glue surface. I would use a tenon although Sam Maloof's graceful rockers use 1/2" dowels IIRC.

Had I not already glued and screwed the joint, I would have used floating tenons in the joint. I don't think I can machine a mortise at this point. Closest thing I see to that is use a dowel. I'm glad to know that Mr. Maloof uses 1/2" dowels in his rockers.

[Sam Murdoch]

After the fact like this I can't see that you would gain anything from adding a dowel. Can't hurt, but I think you could just remove the screw - maybe go up in diameter - and reset it after adding epoxy to the screw and hole. Your concern is the rocker to leg joint and there is something to be said for not boring a 1/2" hole through the rocker. If this is your chair - you might just leave it alone and let it be a living experiment. See how long it takes for the joints to start to fail. Well, that's just an idea :rolleyes:. The problem with my epoxied screw method is that it would be impossible to repair if that joint ever failed.

[Howard Acheson]

Had I not already glued and screwed the joint, I would have used floating tenons in the joint. I don't think I can machine a mortise at this point. Closest thing I see to that is use a dowel. I'm glad to know that Mr. Maloof uses 1/2" dowels in his rockers.

For an adhesive, use a slow set two part epoxy. Epoxy is flexible enough that it can all the racking forces and movement and still maintain a strong joint. In the shop I owned, we used epoxy on all chair joints. Nothing more dangerous than a chair that fails.

[lowell holmes]

Having attended a Paul Sellers rocking chair class, I use m&t joints for the leg to rocker joint. The joint is glued with carpenter glue and then a 3" long wood screw is inserted from the bottom. A wood plug is glued in the hole. I have built five chairs over the last 8 years and none have failed. The tenon is cut with a handsaw and chisel. The mortise is chopped with a chisel. I don't think you have a problem.