Vent window glass seal

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Vent window glass seal

Postby 330GT » Fri Apr 11, 2014 11:44 pm

I broke the shaft on my vent window when I took the car apart for painting. I got a replacement frame and it just came back from being chrome plated.

Now I need to figure out how to mount the old glass in the replacement frame. From the looks when I took out the glass, Pininfarina used some sort of black caulk. I had a dickens of time getting the glass loose, eventually using a combination of cutting, scraping and a heat gun along with some prying to get the glass free.
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I have some thin rubber which is a little too thin to fit tightly.
P1030698x.jpg (39.97 KiB) Viewed 2236 times

Perhaps some black silicone rubber between the channel and rubber and then some on the inside of the rubber to bed the glass in?

Or maybe some 3M strip caulk in black and just bed the glass in it.

Regards, Kerry 330 GT Registry 250 PF Coupe 1643GT, 330 GT 2+2 8755GT, 308 GTS 23605

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Re: Vent window glass seal

Postby tim » Sat Apr 12, 2014 1:47 am

Greetings… If you use a silicone caulk, make sure to use what is called "neutral" curing. It won't smell like vinegar (acetic acid) and it doesn't attack any laminations.

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Re: Vent window glass seal

Postby cory » Sat Apr 12, 2014 6:34 am

Hi Kerry
You can go to any local glass shop that installs windshields and they will have a glass urethane. It will be black and takes a black liquid primer to go on first to adhere the frame to the glass with the urethane. Any excess can be scraped off or cut off with a razor after drying. 3M does offer it but unsure if it will be the same as the glass shops use. It is expensive and may be cheaper asking them for a bead of it. I kept the frame together with tape until it set up, usually 24hrs. If you were closer I would do it for free at my partners glass shop for the information I have used on you site.

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Re: Vent window glass seal

Postby tyang » Sat Apr 12, 2014 7:16 am

Hi Kerry,

You can also use a product that is often called "dum dum" or strip caulk made by 3M. It doesn't dry up and can be cleaned up with mineral spirits. For the vent window glass, I apply it on the edge of the glass and bed it into the chrome frame. When everything is secured, I wipe the excess off with a rag and prep-all or mineral spirits. The glass won't go anywhere once the calk is applied all the inside the frame. Urethane glass sealer will work too, but mistakes are harder to fix.

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Re: Vent window glass seal

Postby afwrench » Sat Apr 12, 2014 7:49 am

Hi Kerry, Jaguar E type roadster suppliers can get you the soft sealer strip used on the top of the windshield. Comes in a strip about 3 inches wide and 6 feet long, plenty to do numerous pieces of glass. It wraps around the edge of the glass and the excess is trimmed with a razor blade after the chrome is placed. It has a soft almost putty like feel as you put the chrome back on. Good luck ,Mike

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Re: Vent window glass seal

Postby 330GT » Sat Apr 12, 2014 8:49 pm

I'll get some black strip caulk and see how that goes.

Thanks all.
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Re: Vent window glass seal

Postby Timo » Sat Apr 12, 2014 11:14 pm

I have fair amount of experience on this and if I understand your second pic correctly it shows some glass sealing tape/strip.
This material should be available in several thickness', but if non of them matches exactly you can try to double it by finding a thickness combo best suited for the application. In some cases I've been able to create right fit by applying a second layer only to one side of the main strip.
Best way, IMO, to assemble these is to install the sealing tape strips to the channel by making sure they will provide snug fit for glass. Then liberally wet the inside groove of the strip and joining edge of the glass with soapy water. Hold the glass standing on its straight edge against a wooden (or similar) work bench top with perhaps a shop towel in between them to prevent chipping and after aligning the molding/trim appropriately use a rubber mallet to carefully tap the molding/trim little by little onto the glass. Keeping the seal and the glass continually wet with soapy water should make the assembly easier. Once the glass is completely seated in the molding, use a razor blade or utilty knife to trim off excess tape.

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Re: Vent window glass seal

Postby David Booth » Thu Nov 17, 2016 6:49 pm

I’m bumping this thread just to show everyone what a mean streak our friend Tom can have.

I’m in the process of putting the doors on my Cab back together, and faced the same problem as mentioned earlier: how to seat/seal the vent window glass in the frames.

My first attempt was with some thin neoprene rubber and RTV sealant. The problem with this was that even with some dabs of weatherstrip adhesive to hold the neoprene to the glass edge, the rubber still wanted to squirm out of position when getting the glass back into the frame; and the RTV wasn’t getting enough oxygen to cure. Scratch that approach.

Second try was going to be with the “neutral curing” Dow Corning adhesive also mentioned above, except that it’s apparently not legal for sale in California. Scratch solution #2.

So already having some 3M “dum-dum” body sealant on the shelf in my shop, decided to follow Tom’s advice above and use that.

So per the photos, I put a ribbon of the stuff on the inside and outside edge of the glass, with the glass itself held in a pair of wood blocks in my bench vise, and then flexed the frame over the glass.

Works fine in concept, until you have to start filling the gaps and getting rid of the excess material.

Pretty soon, I’m feeling like Br’er Rabbit in the Uncle Remus story about the Tar Baby. Fingers are sticking together, the filler is sticking to every place you don’t want it, and I think there’s some in my hair. Even after extensive cleanup with mineral spirits, which may be dissolving some of the sealant I want to keep, there’s always some ready to jump onto unsuspecting fingers nearby and then get transferred all over creation.

I haven’t had this much fun since I chiseled the undercoating off.
Vent glass.jpg
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Vent glass in frame.jpg
Vent glass in frame.jpg (296.87 KiB) Viewed 1532 times
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Re: Vent window glass seal

Postby Suebian330 » Sat Nov 19, 2016 5:21 pm

I just recently had the same Task. I used the rubber of a motorcycle tube. Bevor Installation I soaked it with rubber protective oil. After this it fits perfectly. For cutting the excessive rubber I inserted the blade of a cutter knife to protect the glass.

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Re: Vent window glass seal

Postby TOMKIZER » Mon Nov 21, 2016 5:13 pm

A google search for glass setting tape brought up ebay entries for various thicknesses of rubber tape like in your second photo. The first that popped up was by a company called vintique inc.

I suspect it's the same as the stuff I got in 2007 by visiting an automotive glass shop and talking to the oldest installer in the shop. He raided their attic and found some for me which he immediately gave me since they don't use that technique any more.

If what my search found is like what I bought, it's cork particles impregnated in rubber and comes in several thicknesses and widths, but it looks like what you have in your second photo. For me it worked perfectly but wasn't easy to install.

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Re: Vent window glass seal

Postby Don Micheletti » Tue Nov 22, 2016 11:57 am

Steele Rubber Products has the material that is speciffically for this job. The stuff comes in various thicknesses. I used it on my 275.
Steele makes repro rubber parts for many antuqie cars

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