What caulk to use with cedar?

[dmede]

For Harry Bryan's Fiddlehead canoe he calls for caulk to be applied along the stem and gains of the planks (also the garboard to bottom joint). He also uses it around the edges of the watertight bulkheads to help seal them against the planks and in the seam of the plank lap themselves (not in the lap, just along the outside to help seal).

Harry recommends either 3m 5200 or Sika 240.

I don't know anything about either of them and would like some forumite opinions on what to use for these applications, if there are other choices that might be better.

Also, what color caulk to use with WRC? Tan or mahogany (where it will be visible inside)?

Thanks,

Dave

[dmede]

You can't paint over 5200 at all? It's intended to go in the seam at the laps on the outside of the planks and be painted over.

Does Sika flex the way 5200 does?