How To Seal Your Windshield

1964-1968 Mustangs



1. Warm up the sealant by setting it next to a drop light or mild heat source. You just want to make the sealant warm, not hot. This makes it much easier to pump the sealer. You also want to do this in a garage where it will be at least 65 degrees. This sealer needs to flow to do its job properly. If it is cold, it just won't flow.

2. The window weld sealant uses a standard caulking gun. Snip the end of the sealant tube on an angle to an opening of just around 1/8". Push the tip of the tube into the rubber on the glass side of the seal and apply the sealant around the inside edge where the glass and rubber come together. Work the applicator nozzle between the glass and the rubber. You will get a feel for how much to apply. The more you put in, the more it squeezes out as the rubber goes back against the glass.

3. Also apply the sealer all around the outer edge where the rubber meets the body. You want to pay attention to where the molding clips are. Make sure you pump the sealer in all around the clip. This is the cause of a lot of leaks in this area. The sealer needs to be all around the clip so that you can see it come up and out of the clip as you squeeze the handle on the caulking gun. You want to use a lot of sealer on the body side as to fill any gaps around the rubber.

4. Let the vehicle sit for several hours and then go back and re-apply the sealer in the spots that have sank or settled in. You can see the low spots where the sealant sank in. Re-apply at all of these areas.

5. Let the vehicle sit for around 24 hours and then water test it. Start your water test at the lowest part of the sealed glass and work up to the top. Have someone watch for leaks on the inside of the car while you test it. This is the best method for determining where a leak is.

6. Once you are sure that the window is sealed, re-install the moldings.

7. Clean off any excess sealer with clean-solve or equivalent. Check with an auto body supply shop for a 3M product or another similar brand. Always test your paint in a hidden area before using any cleaning solvent.

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* Please be advised that this information is for suggestion only and is based on prior experience. We at CJ Pony Parts can not be held responsible or liable for any mistakes or injuries connected with the topics covered.