On Mar 22, 10:04 am, Wayne Whitney wrote:
Hello,

I need to extend an exterior window sill and am looking for some
pointers.

My current plan is to make a redwood extension of the appropriate
dimensions (1/2" wide by 7/8" thick) and bevel angle (8 degrees).
Then I'll use the extension as a guide to block plane the existing
sill edge flat (I don't have a jointer plane). I'll attach the
extension using biscuits and polyurethane glue. If there are any gaps
from poor joinery, I'll fill them with an epoxy filler. Then I'll
sand the face flush.

Any comments? These sills are already stepped, so I do want the
extension to be flush.

Thanks, Wayne

Sounds good to me but I'd use small SS screws instead of the
biscuits. Quicker, stronger, less work.

cheers
Bob