budget_bandit
budget_bandit Reader
11/5/24 10:40 a.m.

I'm getting ready to install the rear window in my 1972 Ventura, and i've had to repair the entire window mounting surface. I was not able to match the contour of the original window 100% perfectly, and I'm not sure how big of a deal it is. I'll be using the new style urethane adhesive (as opposed to the old strip caulk GM used back in the day), and I'm sure this car wasn't perfect when it was built. Is an unuequal gap of 1/16"-1/8" okay? Will it bond the window in well enough? Illustration below

jgrewe
jgrewe Dork
11/5/24 3:41 p.m.

It should be fine. Just make sure the glass isn't resting on the metal edge.

RacetruckRon
RacetruckRon GRM+ Memberand SuperDork
11/5/24 7:14 p.m.

The urethane adhesives are quite viscous, I would recommend a powdered caulk gun if you have the means.  The Milwaukee I have made quick work of the 3M window weld when I had to replace the window on a excavator cab for a trade show demo a couple months ago.

budget_bandit
budget_bandit Reader
11/6/24 7:32 a.m.

In reply to jgrewe :

People use rubber blocks for that, right?

budget_bandit
budget_bandit Reader
11/6/24 7:33 a.m.

In reply to RacetruckRon :

Noted...not sure a powered one is in the budget so I will expect a hand workout lol

GreenVWs
GreenVWs New Reader
11/12/24 9:38 a.m.

In reply to budget_bandit :

In my previous employment I was the glazing & glue expert and have lots of experience with urethane. If you haven't installed it yet hopefully the notes below help.

Super important, do not touch the urethan with anything other than the glass going in.  It will get on everything and be a pain to remove later. There are things called "Scrubs in a bucket" that are the best I ever found for cleanup of urethane.

1. Everything must be clean and never touch anything that's being glazed with anything but the glazing materials.

2. Use suction cups to move the glass into position, if you try and hold the glass you will touch areas that are being glazed and compromise the adhesion.

3. Follow directions for any areas to be primed.  I recommend priming the glass and window lip even if using urethane that claims no primer needed.  The primer both helps adhesion and blocks UV from the urethane. Make sure the primer on the frame fully covers, any holes can give rust a spot to get started.

4. Cut the nozzle in a very sharp "V" on one side.  You want the urethane at least double the finished height so there is good squish out everywhere.

5. Warm the tube before trying to apply, that will make it flow a bit better and will speed the initial cure too.  Sitting in a bucket of hot water is a good and safe warming method.

6. Adding some tape alignment marks to the glass and body will help get it in place.  Get it as close as possible while only lightly touching the urethane then push slowly and carefully to the desired finish height.

7. If you know the finished height you need, you can make some urethane spacers by premaking some beads to the right thickness and cutting them to fit. If you use spacers, locate them carefully to avoid making a void in the adhered bead.

jfryjfry
jfryjfry UltraDork
11/15/24 1:57 p.m.

Those are great notes - thanks for sharing

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