Help With Decaying Window - How To Fix The Gap

Question

I have a very old window, that faces the sunny side of our house. Noticed it had some chipping paint and rotting wood on the exterior when we moved in. I got rid of most of the messed up wood, and part of the wood piece directly over the window edge crumbled off (see photo - and try not to laugh at the radio shack security sticker).

The window will eventually be replaced, but I’d like to do an easy fix in the interim to keep things relatively sealed up and moisture free. I’m not really all that handy, so I’d rather not cut bits of wood to fill in the gap.

I’d prefer to do something with caulk (and maybe backer rod for the vertical bit) or latex window glazing that comes in the tube to fill in the gap and seal. Anyone have any advice on what material to use? And if it’s caulk, what kind might be best? Ideally something that has some flexibility and can easily bond to both wood and glass. Something that won’t end up shrinking too much in the sun or cracking the window. It doesn’t have to be pretty - just functional. Any thoughts?

Thanks in advance!

Answer 1

Unless there's some rot in the actual wood that isn't obvious, all you need is window glazing compound. You can choose between latex and oil-based; latex is certainly going to be easier to use and paint.

I have an unverified opinion that oil-based is more durable overall, but given your timeframe, it probably isn't worth the trouble. (Longer dry time, want oil primer before latex topcoat...)