Flexible joint filler

[chudford]

I have a windowsill in a bay window made of 3 sections of wood.

The joints between the sections need to be filled with something.

I have tried polyfilla and various flexible fillers but the joints keep cracking.

Any ideas for solving this problem?

Thanks

[Bob Minchin]

Wood moves. You won't stop it. It's nature at work. Use a suitable shaped wooden moulding and only fix to one side of the joint. Paint underneath first so when the joint moves painted wood shows. Bob

[Stuart Noble]

Bay sills are a pain because, for each joint, you have two sections of end grain sticking out in the weather. They're often well rotten inside before anything shows on the surface. Anything flexible enough to withstand the movement is likely to pick up grime and look a mess.