Condensation on wood window frames, should I use sealant

[compact]

Most of our windows have condensation each morning. The ones in the bays are the worst alongside the bathroom.
The double glazing looks old and narrow, but not blown. There are no trickle vents, roller blinds probably don't help begin so close and hindering air flow. We are now keeping the small window open on the upstairs.
Not sure I can stop the condensation, but trying best to deadly with it. Using a window vac each morning etc.

I'm sanding and tree varnishing, however how is best to seal against the Fran against the glass too stop condensation running down and soaking the wood. A thin bread of clear sealant?

Thanks

 

[compact]

I'm drying the frame, sanding it and there is a bit of gunk where the frame meet the wood. Once the black gunk is out I am is where I'm varnishing the wood and would pop in some sort of sealant? It's about1mm of gunk coming out

 

[Custom45]

Best off dealing with the cause of condensation? Why do you doubt you can stop it? More ventilation and warmer rooms is usually enough.

 

[compact]

Best off dealing with the cause of condensation? Why do you doubt you can stop it? More ventilation and warmer rooms is usually enough.

I agree, though more ventilation would mean drilling trickle vents into the frames or leaving a window open (which makes the rooms colder)

We've had little to none the last two days as it's been dryer and a degree or two warmer.

I'm going to try opening the kids Windows and eventually moving to thicker curtains over thin blinds.

Still curious about three best way to seal wood frame to glass. I'm thinking of wood filler too however matching the wood as using clear varnish will need the trick

 

[Custom45]

Sealing the frame to the glass, I personally would use black or brown silicone (anti mould if you can get it), use a proper silicone smoothing tool, not your finger. I'm a DIYer though, someone else on here will know better.

Regarding ventilation, it sounds like you need mechanical ventilation rather than opening more windows or drilling trickle vents. Do you have extractor fans in bathrooms & kitchen? If so are they old & in need of replacement? A PIV system, if within your budget would probably help a lot.