Need to fix window gap

[omark]

Hi,

I have noticed the window has up to 1/8 inch gap
between bottom of external frame and the glass panel (2 ply).
The window is probably 40 years old and unsure if PVC or wood.

I was thinking about filling the gap with Bondo or caulk (unsure what type though).
I would surely appreciate some advice.

[Snipe Hunter]

Can you post a picture? Should be very easy to tell if it's vinyl or wood. Does it look like plastic or does it look like wood?

[Roly]

Is it the sash itself that is coming apart (rail & stile) ?   If so try to glue frame back together using a pipe clamp if it is a wood frame.    Had this happen on a old Anderson window.   Also added a latch . Roly

[Cooler]

You might add replacement vinyl tracks.  The problem is not entirely clear to me.  But read this to see if it applies:

https://www.washingtonpost.com/lifestyle...21d4146c9e