if you can reach any of the frames, wet a finger and give the frame a rub, just to check if any of the paint or coating is coming off.
Do they have any vents in the top of the frames?
This can really catch you out
So instead of the expression, 'STAY AWAY FROM THE LIGHT!!'
STAY AWAY FROM THE VENTS!
Also, depending on the type of seal between the glass and the frame, muck can gather here and make you look a fool
Wash wash, rinse rinse, make awful swearing noises, mutter darkly about large hammers and extreme violence, and do it all again
Once you have got it right, it all falls into place
Unless the paint has oxidized of course
Ian