Jim Weisgram wrote:
[...snip...]

The second idea is that I came across a product that is basicall
small metal strips that have serrated teeth. These are used to wrap
around the dowel or mortise and reinsert back into the joint. Made by
"Woodmate's" and called "Mr Grip Furniture repair kit"


I've used those. They do help loose joints grip. I don't think they
would work well over the long haul in a chair, however.

FWIW, there's a Bruce Hoadley article on dowel joints in the Fine
Woodworking archive that might be of interest--he explains why they fail and
has some suggestions on what do do about it. The article can be reached
from
http://www.finewoodworking.com/Skill...F.aspx?id=2044,
but you need to have a Fine Woodworking Online subscription to see it--they
have a two week free trial so you don't have to pay anything to get it
unless you've already used up your trial.