Dowel ft

[timber]

Any suggestions as how tight a fit dowels should be--- I have just turned up a few out of oak for my chair seat. I know I have got to let the air expel when I glue up, do they have to be a slightly loose fit ,or tight with a groove along the length of the dowel ??? They are 8 mill approx by the way
Thanks

 

[Paul Chapman]

They should be a snug fit. Cut one or more grooves along the length to allow excess glue to escape.

Cheers :wink:

Paul

 

[AndyT]

Snug enough that the pieces need a thump from the heel of your hand when they go together. Not so tight that you need to hammer the dowels in.
You must have grooves for glue to escape. Without them you can burst through the wood by hydraulic pressure.

Snag is, water based glue can slightly swell the wood so do some trials (with glue) first.

One last tip - 3/8" and 9mm are very close. If one is too loose, try the other.