I am in the process of painting my timber frame windows and when cleaning and sanding down I have noticed that there is a small gap between the window pane and timber frame on the interior (the stuff which was in the gap has come away etc. when prepping). I am wondering what I can use to fill the gap and then paint over it to give it a nice finish (the gap looks pretty ugly!).
Here's a picture of the gap.
I'm aware of window putty and decorators caulk but do not want to use the wrong thing and create more work for myself! Based in the UK if that helps with product recommendations.
Best Answer
I would recommend using glazier's putty, not "regular" caulk. Glazier's putty is designed to bond to glass and wood/metal/vinyl and to stay flexible for decades to provide a good seal for your glass.
A simple search for "glazier's putty" turned up quite a variety of options. This page was one of the first and describes and ranks several different varieties for different applications. (No affiliation with the site or guarantee of the suitability of his opinions to your application.) If you were a pro and staking your reputation and income on your choice of putty, this might be very valuable. Since you're only doing a few windows, you may just want to go with the smallest tin you can find at your favorite local hardware store.
Several sites indicate that it can be more difficult to work with than simply squirting caulk from a tube. I have reputtied a couple of windows and didn't find it terribly difficult. It's rather greasy stuff, though, so expect to give your hands a good scrub before grabbing a sandwich for lunch.