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Replacing hatchback glass

Stang85GT

New Member
Have a used replacement glass for my 1985 GT rear hatch and request advise on how to go about it. I have read other threads about the special tool recommended to unclip the metal trim and the care needed not to damage the trim. I have the following questions:
1) Does all the rubber material need to be removed from the hatch before inserting the replacement glass?
2) The replacement glass has approximately a 3/8" thin rubber strip around the edge. Does this need to be removed before installing, or leave it on the glass?
3) Presuming from reading other threads that polyurethane is used as the agent to adhere the glass to the hatch. Is there a recommended brand and/or suggestion on where to obtain this product?
I want to save some money, and "looks" are less important than function on this project. Appreciate advise from anyone that has performed this task. Thanks.
 

broncojunkie

Active Member
I would suggest finding a glass installer to do it. It's not overly complicated, but does require a little finesse to do correctly and it's very easy to mess up with a minor mistake.

Having said that, you may want to try it anyway. As far as I know, all original hatch glass was installed using a butyl-like product. It never fully hardens like urethane. Easy to cut out (particularly in summertime). You can replace it with butyl tape, but urethane is now considered a much better option. Unfortunately, you will need to remove all traces of the butyl before applying urethane. There are different ways to remove it, but you can research it if needed.

You also want to minimize damaging the paint in the pinch weld area. You may need to do some rust repair or, at the very least, touch up areas where bare metal has been exposed. Do it correctly (a shot of rustoleum is not the way! )

There is a clear primer made specifically for prepping glass before the install. You clean the glass first and apply the primer around the sealing edge of the new glass. I've installed glass before without using it and never had a problem, but I would suggest using it. This product and the urethane can be purchased from a local shop or ordered online. Local shops will probably sell you a good commercial brand, but the 3M stuff sold online is fine. You'll need 2 tubes and a good heavy-duty caulking gun. There is a particular way to cut the applicator tip when you're ready for urethane. I can't explain it here, but watch some videos to see what I mean. It will give you a good TALL bead without putting down a ton of urethane. This what will give you a good seal.

I have no idea about the plastic trim around the edge. I've never heard or seen it personally. You might ask a tech at a local shop. While you're there, see if he can install it for you for $75 and a case of bud!
 

Stang85GT

New Member
Thank you much for the detailed response, very helpful. I watched a two-part video and now understand the applicator "V" tip shape and how to apply. Product reviews indicate success using a manual gun if urethane is warmed beforehand, but most suggested a power/air operated caulk gun that would likely be cost prohibitive for my single window installation. Appears that a decent heavy duty manual caulk gun is $50 and up. The best quote I received to have a professional tech install the used window is $138 + tax, so I will need to decide how to proceed. Thanks again!
 

broncojunkie

Active Member
I just did one a couple weeks ago. It was 45 degrees outside. Urethane was room temp. I used a $20 manual gun from the local hardware store. I just took my time and wasn't squeezing the guts out of it.
 
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