Sedan Rear Window Molding Bumper

[TonyE30]

Looking for a suitable replacement for rubber bumper on the inside of E30 sedan rear window air outlet molding (51131922331 and 51131922332). Mine manged to degrade/melt/rupture(?) in my hot garage over the course of past 2 years.

“good” example from web search on molding part
number:

My melted mess:


Are they some sort of fluid-filled bladder that popped? Or is a a rubber of some sort that simply degrades over time? It appears as if it were a butyl-filled rubber blister, sort of like a gusher candy.
want to make sure trim sits properly and doesn’t rattle on the freeway once I reinstall - 51131870459 clips and 51131904479 are proving expensive enough to not want to have to break/replace multiple times.

[Vincenze]

Can a weatherstrip rubber foam tape from Home Depot do the job? Tapes are available in different widths and thicknesses.

[TonyE30]

Can a weatherstrip rubber foam tape from Home Depot do the job? Tapes are available in different widths and thicknesses.

May need to go the weatherstripping route, I discussed with Bumper Specialties & Sorbothane - hard to find something that's low durometer and outdoor friendly - going to buy some samples but not finding anything great. Probably going to look at an automotive-grade product (likely from 3M) if I go the adhesive-backed foam route, learning that a high-quality acrylic adhesive is likely what I'm looking for.

[Vincenze]

May need to go the weatherstripping route, I discussed with Bumper Specialties & Sorbothane - hard to find something that's low durometer and outdoor friendly - going to buy some samples but not finding anything great. Probably going to look at an automotive-grade product (likely from 3M) if I go the adhesive-backed foam route, learning that a high-quality acrylic adhesive is likely what I'm looking for.

Could something like this work?

https://www.ebay.com/itm/389385621483

3M Products Window-Weld Sealer

https://www.summitracing.com/parts/tes-7100066530

[TonyE30]

Could something like this work?

yes that looks like a good option for material, but not thick enough - looks like the old ones are about 9mm "tall" uncompressed. I've ordered Sorbothane 0510134-30-10 & 0510134-50-10, we'll see if either of those ends up being the right fit of durometer and size. A little worried about swelling when wet, but got the urethane coated ones to hopefully help with water resistance.

[Vincenze]

Here's what an expert used. Neoprene foam.