The Stovebolt Site Forums The Shop Area Interiors Silicon vs glass setting tape

Have used search feature and can't seem to find a definitive answer..installing new door glass and vent glass in my 54... Not a show truck and not concerned with being original ... Why can't silicon be used to set these glasses instead of glass sitting tape?

Why not, indeed! I used a urethane sealer to glue the glass in. It may be a bit of a challenge to remove the glass if that's ever required...

If modern adhesives had been around in the 1950s, I suspect that GM would have used them instead of setting tape.

That was my thinking...thanks for your quick reply!

Urethane can and is used for this, just be sure to use a couple pieces of setting tape (I've even used the cardboard off a razor blade) to center the glass in the channel. If you use silicone, be sure it doesn't contain acetic acid (vinegar smell). This will cause rust as a lot of glass guys learned the hard way. Also, if you glue the channel on with the glass in the door, be careful not to roll it up and glue it to the cat whiskers. Don't ask how I know! Also, be careful rolling it down if the urethane or silicone isn't cured, you'll be starting over with a mess. If you ever have to take the channel off, you'll need to heat it with a propane torch, so I don't recommend this method for the vent glass. I've used this method many times over the years for door glasses, mostly by sliding the glass in with the channel and glass in the door, mainly because it's quicker and easier, and one shop I worked for claimed setting tape was obsolete. John

I use black Hi-temp RTV sealant. Work fine, last long time. I thought about urethane, but shivered at the thought of ever being able to clean it out of the channel if I broke a window.

RTV sealant...hadn't thought about that. Both glasses are out of truck but will make sure whatever I use is good and dry....are the cat whiskers glued in?

I recommend tape. Tape centers the class in the frame, clamps and seals. RTV, and the like do not center, RTV is not evenly distributed. It is wiped out somewhat as you put glass in frame. Thin on one side think on the other. Has low shear strength. It's a lazy man's install. Do what you want but I'm giving the other side of the story.

At least Tinnerjohn said center it with spacers.

Modern side glass has no frame. So no tape or sealer used. The only sealer used is on some modern windshields. Which went to a locking strip then to just sealers.

RTV= Room Temperature Vulcanizing......

I am in full agreement with bartamos.

Why not use the original style soapstone impregnated glass setting tape?
Yes, you might have to find different thicknesses to get the correct thickness of tape (Restoration Specialties and Supply, Inc, and others).

One advantage (besides being original, and being a conversation topic) is that future broken/cracked glass can be easily (and cleanly) removed (soak the tape in gasoline/kerosene/solvent and the glass easily slips out or in). Nice and neat and clean - installation and removal.

The reason I use the RTV is because I could never find the right thickness tape, and the local glass shop was absolutely no help, but they did offer to sell me an entire roll for a small fortune with no return if it was wrong.
As far as centering it in the channel, how in the world could 1/32" one way or the other make any difference in the world with this application? (Serious question.)
I am all for doing things the original way, but no one will ever know that I did not in this case.
Carl

Sold by the foot at around $1 per foot at a Restoration Specialties.

Now that you fessed-up - We will know.

I get tape at local SoCal. Measure channel inside, measure glass, subtract, divide by 2. Measure the NEW glass for this calculation. Old glass is 1/4 (.250) thick. New glass from "off shore" is in mm, like 6mm, like .236 thick or less. Most of the time .045 is the correct thickness for my trucks. Some places call it 3/64. I use the rubber black tape, NOT the cork rubber sold by Classic trucks.
Some may not think a lop sided window as bad. If the RTV renders 1/32 (.031) difference, that would be almost zero on one side and .07-.09 on the other of the glass in my era trucks. If that's OK, it's OK. Just pointing out the goodness of tape.

The only problem that I had using tape, was choosing the correct thickness.

Since I had bought at least 4 thicknesses, I dry tested until I got the one that was tight, but allowed a little “push down” of the glass.

Put a little oil in the groove
Push down the glass.with dry tape on it
Add more oil at the top of the tape (a couple of times over a 30 minute period
Leave the assembly in a vertical position for a day
Cut off the tape at the edge of the base/frame
Add a little more oil along the top of tape
You get excellent tightness, and excellent original appearance, and the ability to easily remove the glass, if ever needed

To clarify, I preferred to use setting tape whenever I could, and that's what I'll use on mine when I get to that point,but when you are replacing glass for a living, sometimes due to time constraints and the materials provided you have to take shortcuts unfortunately. I mainly wanted to stress centering the glass as I have seen glass that broke because the channel was cocked, placing it in a bind. Also, lower channels continued to be used, but were only a few inches long, necessitating that they be glued since tape didn't provide the necessary strength. The newer cars and trucks have a narrower channel also. I just wanted to share some of my experience gained over 35 years or so in the business, under all conditions. John