3M One Step Primer and 3M Windo-Weld Test Results

If you've been following this thread you know that tighed1 had great results in repairing his rear window roadster glass with 3M Brand Windo-Weld, #08609, which has held tight for 1.5 years. You can't argue with success, so I went out and purchased a tube at Autozone for $19. While reading the directions for use I noted that 3M stated that you needed to use their 3M Single Step Primer, #08681, when using the Wino-Weld on glass, so I went out and purchased some on the internet from Fox Run Tools for $29, which included shipping.

Once the 3M primer arrived (2 days!) I set about thinking how to test it out before using it, so I found a piece of glass, cleaned it properly, and then applied the primer to a section of the glass, coating an area about 1 foot long by 1 inche wide. After letting it dry for 15 minutes, I then applied a bead of the Windo-Weld straight down the middle of the dried primer, and then did the same on a section of the glass not coated with primer. I then used a single edge razor to slightly flatten each bead of Windo-Weld, much as would happen when it would be applied between the roadster glass and canvas top.

24 hours later, after the Windo-Weld had dried (technically, it actually "cures"), I tried removing it from the glass with my fingers. On the non-primed side, once I was able to get a grip on the Windo-Weld, it peeled off without much difficulty, much like removing silicone caulking on glass, if you've done it before.

I now tried to remove the Windo-Weld from the primed side with my fingers, and it would not budge -- it was like the Windo-Weld was part of the glass! So, I resorted to using a single edge razor, and even though it was a new, never used razor, I had some real difficulty cutting the Windo-Weld off the glass. It just didn't want to be removed! So, needless to say, I will be using the 3M Primer on my glass when I attempt to repair my roadster window today.

I'll post some pictures of my project and then provide some honest feedback on how it all went.

And, to give credit where credit is deserved, I want to say thank you to tighed1 for his sound advice on the 3M Windo-Weld product.

Best regards -- Bob