I have been getting ready to install my new windshield, with some friends scheduled to help. I bought the butyl rope from 914 Rubber about a year ago, and it is 9.5mm thick. Now, their website lists 8mm. I see other references to 5/16", essentially 8mm.

WTF? Did the spec change? I know the glass has to sit level or just below the surrounding frame in order for the aluminum trim to seat. Has anyone used the 9.5mm stuff?

The 914Rubber butyl is too thick. Go with 5/16. I did get the thicker butyl to work, but I had to put the car out in the hot sun to soften the butyl and massage the glass down to get it level. Pretty scary.

I've seen people claim that the Chinese glass is thinner and needs the thicker rope. I disagree. I installed XYG glass and still wish I'd used 5/16.

I did this last year and wished I had slightly thinner butyl.
My windshield is old US made aftermarket glass and I don't know how the thickness would compare.

Jim

We did move to the 8mm as it was easier to work with.
-Mark

8mm. Be sure to roll it out uniformly. As it comes off the roll you will notice there are 2 flat spots where the paper separates the strands. Don't twist it keeping the same flat against the glass the entire way. It's going to work no matter how you unroll it (or even if you use 3/8' tape) but if the butyl remains the same height the entire way then you'll have a uniform surface and an easier fit with less massaging. 45 your splice for a neater job too.

5/16 and make sure it's reasonably warm (soft)

914Rubber sent me the 8mm butyl which worked great. Butyl isn't that expensive, sounds like using the thicker 9.5 isn't a good idea. Order up some correct 8mm stuff.

Because my garage was around 55 degrees, I set the windshield, then put one of those oil filled space heaters inside the 914. Over a few hours was able to gently squish the glass down where it should be. Warm days are your friend for sure.

Not too far off topic as it is windshield related. I need to install a windshield in a 70 factory six. Do you know when you might get back in stock the clips and the chrome trim? Thanks, Jeff

8610 is 3M's 1/4" butyl. ive seen that recomended

I got clips from 914Rubber and only replaced the ones needed. I got new trim from Stoddard. It was boxed in such a way the pieces were not folded.

If I recall correctly, the factory specifies 8mm

purchased my window trim kit on Nov.27th 2020, at what point in time did you starting using the smaller 8mm. thanks

Somewhere in that range. The slightly thicker stuff can be used, but you have to stretch it as it's installed. That's how I did mine. The 8mmyou can just squish. Again, making sure it's warm is the key.

Measure what you have if you want to, we can swap it out for you.
Drop the shop a call.

Last time I used a hard rubber roller that was for installing laminate tile to even out the trim. It took out some of the waves and made it lay even.

I would be cautious with the stretching method, the results may be inconsistent. Be careful with any tape or method, glass breaks easily