We are getting ready to paint exterior windows. We have three "fixed door" windows on the front of our house. The glass is a bubble envelope (not sure the technical name); it is insulated, but instead of a true double-paned glass, it is one continuous glass wrapped back on itself with an air insulated gap. While prepping the area, I noticed a putty in between the glass pane and wood frame. I'm guessing that this is a glazing putty (after I did an internet search!).
My question is...Do I reinstall more glazing putty or put some exterior acrylic caulk (like we've been using on the rest of the house trim)?
Keep in mind that I'll be painting over this. Some of the putty that is there is black moldy looking, so I'll be trying to pull as much out as I can.
Also, what method of cleaning is typically used in preparation for glazing putty? If that is what is recommended to use.
Thanks in advance!