What type of crack filler to use?

I have been restoring a 16' wooden boat. Hull is plywood with west epoxy system. Two coats of primer have been applied to the rails. As you can see, I tried to fill it with Elmer's carpenter putty, and it cracked, from thermal stress. Where the crack is , is at the joint of the rail and the hull. The outside rail is pine (don't ask why, I didn't build the boat) and the hull is marine ply, so my guess is they expand and contract differently.

Heres my question: What can I use to fill the crack that will be strong enough . After filling the crack, I just need to sand and paint and will be done.

Also, there is a spot on the transom that I had to chisel out and it needs to be redone as well. Can I use one one product that will fix both problems?

Any ideas are appreciated

PICTURES:

Transom
http://s622.photobucket.com/albums/tt310/fox16/?action=view&current=CIMG2663.jpg&newest=1

Rails
http://s622.photobucket.com/albums/tt310/fox16/?action=view&current=CIMG2661.jpg&newest=1

Re: What type of crack filler to use?

Hull is plywood with west epoxy system.

Click to expand...

Ayuh,... Peanut butter from resin, cabosil,+ microbubbles would work...
5200 might work on the gunnels,... It has alittle "give" to it...

Re: What type of crack filler to use?

sounds good. thanks for the help