As the owner of a 2-door Gen 2 XJ, I’ve run into the well-known issue: replacement quarter panel window seals are basically nonexistent. The problem’s only gotten trickier since I recently installed the older-style two-panel quarter windows from a Gen 1 XJ.

With no off-the-shelf solution available, I’m looking to rehab the original weather seals on these newly installed windows.

I’ve been bouncing ideas around with ChatGPT over the past few days, and the AI helped me develop a step-by-step restoration plan. Before I dive in, I wanted to get some feedback — do you guys see any flaws, better alternatives, or pitfalls I should be aware of?

ChatGPT:
🧰 Goal: Seal cracks, build up aged rubber, and achieve a clean matte black finish — safely and durably.

🔧 Materials Needed

• Flex Seal aerosol (Black)
• Plasti Dip spray (Black)
• Masking tape + masking paper/plastic (for paint/body only)
• Gray Scotch-Brite pad or 1000+ grit sandpaper
• Isopropyl alcohol (70% or higher)
• Razor blade scraper (metal or plastic, ideally with handle)
• Glass cleaner (Sprayway, Invisible Glass, etc.)

✅ Step-by-Step Instructions
1. Prep the Area

• Clean rubber thoroughly with soap and water, then wipe with isopropyl alcohol.
• Clean the glass thoroughly too — no oily residue, just a clean surface.
• Mask off paint and body panels only — skip masking the glass since you’ll razor-clean it later.

2. Apply Flex Seal

• Shake the can well.
• Spray light, controlled coats, allowing ~15 minutes between passes.
• Build up only where needed to fill cracks or reinforce weak spots.
• Avoid thick pooling or runs, especially on the glass.
• Let it cure fully for 24–48 hours.

3. Scuff (Optional but Recommended)

• Lightly dull the Flex Seal surface with a gray Scotch-Brite pad or fine sandpaper.
• This removes gloss and helps the Plasti Dip grip better.

4. Apply Plasti Dip

• Shake well.
• Apply 3–5 light coats, spaced ~10 minutes apart.
• Focus on even coverage for a uniform matte black finish.
• After your final coat, remove masking tape while Plasti Dip is still wet or tacky to avoid peeling.

5. Clean the Window Glass

• Use a razor blade scraper at a shallow angle (~30°) to gently remove any overspray from the glass.
• Follow up with glass cleaner to finish the job.
• Use a plastic razor blade if your glass is curved or if you’re worried about scratching.

💡 Tips for Success

• Always start and stop spray passes off the surface to avoid uneven buildup.
• If Flex Seal builds up at the tape edge, score it lightly with a razor before pulling tape.
• If you want extra longevity, you can topcoat the Plasti Dip with matte clear Plasti Dip or matte clear enamel.

Before:

 

Is this a cosmetic restoration or a functional restoration? Are the seals leaking? Or do they just look faded and you want them refreshed to match that awesome paint job?

If cosmetic only - I think this route you've outlined looks great in general. Since your XJ looks so darn nice with the paint job (slightly jealous..), I would do a start to finish test run on something else first (maybe your original window trim?) before I attempted on your ride. Just to see how it goes and have a better idea of the expected outcome. Then you can tweak your program if/as needed.

If the seals are leaking, the time to work with them for correction was before the replacement windows were installed.

 

This is a cosmetic thing, we’ve had a lot of rain over the past few days, and the interior of the windows seems fine.

Thanks for the tip, I think it is a good idea to test on the original windows first to perfect the technique. Also I can see how easy it will be to clean off the flex seal with a razor blade.

 

By chance did you get those swing out windows for dirt cheap from an older guy driving a white 4 door Cherokee who wanted those windows to go to a good home ?