Butyl or Urethane?

[70 Challenger Lover]

Getting close to putting the front and rear glass back in. I assume the factory used butyl but I was wondering if it would be better to use a modern urethane made for today's glass installation. Any drawbacks to the urethane in an older car like ours?

[jimynick]

For my  , it'd be a high modulus urethane all the way. I've actually seen guys kick old school butyl installed w/s's out of a car and the idea is to retain you inside the car- not out on the road in front of it. 

[70 Challenger Lover]

For my  , it'd be a high modulus urethane all the way. I've actually seen guys kick old school butyl installed w/s's out of a car and the idea is to retain you inside the car- not out on the road in front of it. 

Thanks!  I think I will go that route.

[70 Challenger Lover]

I was just getting ready to order a couple tubes when I noticed one end had a metal pop top like a grease gun cartridge. Does that mean the glue is exposed after you pop the tab like grease is in a grease tube? The instructions said it requires a caulking gun but that would make a god awful mess of my gun if it doesn't have a plastic plunger inside. Anyone use one of these before that can enlighten me?

I don't see any special guns for these or maybe I'm not searching right.

[70 Challenger Lover]

Here's what the bottom looks like. As far as I can tell, all the other brands look the same.

[1 Wild R/T]

It should still have a plastic piston in the tube, just making sure no oxygen gets to the urethane cause if it does the stuff will set up & you'll never get anything out of the tube...

Personally I use Butyl cause changing a windshield thats glued in with urethane is brutal...  I use urethane around the perimeter of the glass to assure a good seal, basically I force as much urethane under the glass as I can then I form a 45 degree taper from the top outside edge of the glass down to the bottom of the window channel right where it bends up 90 degrees...

[70 Challenger Lover]

It should still have a plastic piston in the tube, just making sure no oxygen gets to the urethane cause if it does the stuff will set up & you'll never get anything out of the tube...

Personally I use Butyl cause changing a windshield thats glued in with urethane is brutal...  I use urethane around the perimeter of the glass to assure a good seal, basically I force as much urethane under the glass as I can then I form a 45 degree taper from the top outside edge of the glass down to the bottom of the window channel right where it bends up 90 degrees...

So at a 45 degree angle, none of it gets on the trim clips?

Do the e body cars use some sort of shim or spacer to keep the glass from sliding down? And if so, can they come out after everything is dry?

[1 Wild R/T]

It should still have a plastic piston in the tube, just making sure no oxygen gets to the urethane cause if it does the stuff will set up & you'll never get anything out of the tube...

Personally I use Butyl cause changing a windshield thats glued in with urethane is brutal...  I use urethane around the perimeter of the glass to assure a good seal, basically I force as much urethane under the glass as I can then I form a 45 degree taper from the top outside edge of the glass down to the bottom of the window channel right where it bends up 90 degrees...

So at a 45 degree angle, none of it gets on the trim clips? Exactly...

Do the e body cars use some sort of shim or spacer to keep the glass from sliding down? And if so, can they come out after everything is dry?  Yes, they sit in the to recesses at the bottom which are kinda wedge shaped... By siding the position side to side you can raise or lower the glass, you want to center it in the opening.....  Personally I put the glass in without any seal, shift it around till it is centered in the opening then tape from the body to the glass on the top near each side and on the A pillar on both sides... Then cut the tape with a razor blade & leave it on the body & glass... Now as you set the glass the tape gives you a clear, easy to see reference... Oh, if you want you can remove the shims, I don't, I use rubber blocks that won't hurt the glass or the body so I just leave them in place, they are hidden under the trim.... It's how the factory did it, why should I do it differently?

[70 Challenger Lover]

Perfect, thanks!

[RUNCHARGER]

Yes: Leave the blocks in, they will support the glass from trying to drop especially in the heat.

[70 Challenger Lover]

I'm going to use urethane so being an adhesive rather than a sealer, I assume it will never move once cured. I'll still leave the blocks in though. Seems like good insurance. Are the blocks a specific e body item or do I need to make them?

[RUNCHARGER]

I cut them myself usually. I use belting or whatever else I have laying around the shop.

[kawahonda]

One thing to mention, and I don't know if it's "generally" true or not, but butyl strips leave for a cleaner look.

Urethane goop--you can see it while inside of the car.  It doesn't really look as clean.

I got the best guys in town to come and install my windshield. They do classic cars all the time, and they used urethane after a deep cleaning and rust-proofing on my ebody. They probably wouldn't use butyl even if I asked them because of warrantee/safety concerns.

I think urethane is the "best" way, but just keep in mind you're likely going to see some of your bead work from certain and even common angles inside of the car, no matter how clean you are, you'll see the goop. You get used to it after awhile, but it isn't as "clean" as butyl strip as I would imagine.

[kawahonda]

Here's a cockpit picture of the camera purposely lifted "up" more than your head would be, and it's quite visible.

[YellowThumper]

One other point to note about the two options.
With burly strips (iirc 5/16") it will hold the window up to correct height for the trim to sit flush.
Using urethane the height is determined by the size of the bead laid down. Eventual plans for me will be urethane and I will shim lower as discussed. I will also shim overall height position as well.