W123 Application, rear window.

Removed rear window to replace headliner. Got my seal and getting ready to re-install glass.

The GREAT news: ZERO rust ...

The Odd news: looks like plumbers' putty was used around the channel.

Is it safe to remove this stuff? Why was it installed? Did the factory do this? If removed, do I have to re-add new putty?

I want to clean out the channel and apply clear POR-15 so it won't ever rust ... ever ...

I don't know of this car specifically, but some cars use body seam sealer around the pinch weld to keep water out of the car.

No, this is putty around the entire perimeter ....

Had a glass shop R&R the rear windshield on my W123 300CD so body shop could repair the rusted channel. No sealer of any kind used, just a new ($$$$) gasket.

It is a coupe hence the $$$$ and I wanted to take no chances cracking that rare windshield.

Bottom line is; a clean and unrusty channel should require no sealant goop.

It is not sealant.

It appears to be plumbers' putty. It is still pliable.

I recall reading about this, but I cannot recall where.

I planned on cleaning it out, but I believe the rear window has never been removed.

I am wondering if this came from the factory like this ???

OK, looks like a little more detailed research would have resolved this on my behalf ...

MB 001 989 31 20 Sealant, non-hardening ...

I use " 3M - Auto Bedding And Glazing Compound. Part #: 8509 " on rubber gasketed glass after it is installed but before a lock strip is finished. 3M Auto Bedding and Glazing Compound 1/10 gal cartridge 08509 NAPA should have it under their brand as well.

Put the caulking nozzle under the lip between the gasket and body and flow around the top and sides, this keeps water from laying under the gasket. The stuff is liquid butyl that skins over but does not dry. It is messy and will stick to everything but cleans up easily with mineral spirits. It is also good for sealing leaking glass that you don't want to remove.

Don't use urethane as this is for glued in glass.

Thanks !

I plan on using both then ...

You are welcome, however, both kinds of sealer are probably not needed.