1966 Mustang fastback, gt 350 , repo back glass fitment , install or problems

[bobboss351]

   I have 2 shelbys in my shop, both are  66  fastback cars in the shop, customer suppled glass for both cars, there from a supplier i have used alot, the cars have original quarter panels and roof panels and the transition panel between the back glass,,,, The problem is the aftermarket glass is about 3/8 inch wider than the original  back glass [located  from a  local mustang guy,,,, The supplier as i said I have used and have a relationship with and they order these back glass 70 pieces at a time,,, no one had a concern reported to them about install concerns, i had my son run the glass back to them as there located here in Minnesota , along with the original and they are agreement with me that the new glass is not the same size,,,,, both cars are very close to the same opening size and flanges,,,,,
   so am I  installing it wrong ?
  Normal i start at the bottom of the glass and pull the cord over the lip, work my way up ,, i have installed probably 25 back glass ,  67 68 69 70 71,,, this is the first 66 glass , so am i doing it wrong,
  during the install ,  if I go up one side to the top and then go over to the other side , The glass and the rubber seal has climbed the flange and is against the quarter panel flange, were the trim clip ,clips into the pin ,,,, i have tryed this about 3 to 4 times and get the same result, any ideas,,,, 
Should i start at the top were the glass is widest and go to the bottom? 
  appericate any help,,,, or recommendations of were to get another piece of glass,,,, Bob

[KR Convertible]

Seems to be an ongoing problem.

https://www.saacforum.com/index.php?topic=15306.msg125296#msg125296

[Greg]

   I have 2 shelbys in my shop, both are  66  fastback cars in the shop, customer suppled glass for both cars, there from a supplier i have used alot, the cars have original quarter panels and roof panels and the transition panel between the back glass,,,, The problem is the aftermarket glass is about 3/8 inch wider than the original  back glass [located  from a  local mustang guy,,,, The supplier as i said I have used and have a relationship with and they order these back glass 70 pieces at a time,,, no one had a concern reported to them about install concerns, i had my son run the glass back to them as there located here in Minnesota , along with the original and they are agreement with me that the new glass is not the same size,,,,, both cars are very close to the same opening size and flanges,,,,,
   so am I  installing it wrong ?
  Normal i start at the bottom of the glass and pull the cord over the lip, work my way up ,, i have installed probably 25 back glass ,  67 68 69 70 71,,, this is the first 66 glass , so am i doing it wrong,
  during the install ,  if I go up one side to the top and then go over to the other side , The glass and the rubber seal has climbed the flange and is against the quarter panel flange, were the trim clip ,clips into the pin ,,,, i have tryed this about 3 to 4 times and get the same result, any ideas,,,, 
Should i start at the top were the glass is widest and go to the bottom? 
  appericate any help,,,, or recommendations of were to get another piece of glass,,,, Bob

I guess I'm confused with your post, you state clearly that the glass is not the same so that is your problem.  Other cars that used the glass and it worked my have had a lot of work done to them through the years which is why the repo glass works.  I would send it back so they can inform their supplier and then you locate another glass that fits.  What am I missing?

[bobboss351]

   Greg, the supplier is aware and they had 4 more in their inventory that matched the ones that came from there shop. We matched all of them to the original glass i have, there all larger than the original one . The original is severely scratched
any one know of another supplier, ECS buys there glass from this place too, so , ECS not going to be a source, Bob   

[poboy427]

Here is what I discovered while I worked thru the same issue. Vendors frequently don't want to drop what they are doing and go measure a piece of glass. I could not find any in stock due to the Covid supply issue last Mar anyway. Most do not even stock glass but rather drop ship.I talked to all that claim to sell rear glass and got no satisfaction.

I discovered that it is hard to tell someone over the phone where to measure he glass even if they had one in the warehouse for comparison. I never trust anyone to read a tape measure on my behalf if I can help it. Measuring tapes can vary minutely (1/16") and the guy reading could be a wobbler, trying to measure and eat a sandwich at same time.  Ever seen a bad trim carpenter's work?

Shipping glass back and forth can further exacerbate the no fit return issue, like the bad fitting glass you already have.

Few glass makers out there. Most, if not all, originate off shore and then warehoused here.

See the other thread on here where I discuss sanding a 1/4" off both sides. Total nightmare, hard on shoulders. I can't imagine paying someone shop wages to do that so that leaves the car owner. Build zero heat on the glass so NO power sanders unless you are brave and don't believe in harmonics. Wear a mask to keep glass out of your lungs and safety glasses too. Be prepared for it to explode at any point. My ill-fitting glass was good at the top and bottom. Issue was side to side thru the middle.Bowed fat.

Let us know how you do.
Ray

Incidentally, I bought my ill-fitting glass 4 yrs ago so there is apparently a lot of bad  65 66 rear FB glass in the pipeline. Just discovered the no fit issue when my restoration was ready for the glass. I had no issues with front glass. Have know knowledge of bad filling coupe glass.

[bobboss351]

Ray,
thank you for the reply,,,,it seems like you stated flat in a area, actually it is about 12 inches in the center of the glass, question,
We took the glass back to the supplier and they tried to remove/trim off the excess and shattered the glass, but they used a  grinder, what grit and did you use water to cool the glass, bob

[KR Convertible]

I have used an angle grinder with a diamond wheel to reshape coupe glass to use in a convertible, but it's a much smaller piece.  I always kept the wheel direction going along the edge of the glass, never across the edge.

I would think a diamond sharpener might work well.

https://www.dmtsharp.com/sharpeners/bench-stones/diamond-whetstone-bench-stone/8-in-diamond-whetstonetm-sharpener-extra-coarse-with-hardwood-box.html

Harbor Freight sells a cheap one.  Finer than the black DMT one.

https://www.harborfreight.com/4-sided-diamond-hone-block-92867.html?utm_source=google&utm_medium=cpc&utm_campaign=12169518939&campaignid=12169518939&utm_content=114845782257&adsetid=114845782257&product=92867&store=151&gclid=Cj0KCQiAuvOPBhDXARIsAKzLQ8F-TDGR0qYe0R2RqxdTpjPTfu8wFwyS9sRBxZeW7Hx-d4Cjd_yCmGAaAo8rEALw_wcB

[poboy427]

Bob-used no water.

I looked at diamond files for sharpening knives but they were out of production-made by Kitchen Aid. Others I saw listed that looked suitable upon close inspection were just fingernail files. What I used was 180 grit dry paper and a palm size rubber autobody sanding block. Lots of paper. Paper spoils real fast.

I'm telling you it is brutally slow. I had nothing to loose. The glass vendor said he wouldn't consider exchanging my glass because the glass and box it came in were 4 yrs old. Like I told him, "the glass did not grow, over time, waiting to be installed." Acted like he had never heard of an issue like mine and showed no curiosity to understand.

So my choice were to set the bad glass in the corner or break it trying to narrow it, cuz I could not unload this fat glass on another hobbyist.

AutoCity in Isanti, MN bought out PS Glass in WI. ECS, all same junk glass.  I know of no NEW fitting rear 66 FB glass on the market at this time. A lot of the glass is made in Nigeria.

[bobboss351]

Alright  guys,
    First thank you,,,,, great feedback, much better than expected,,, im going to attempt a diamond file and belt sand ,, I will post my results here and let you know if break it to pieces,,,, 
   Thank you,,,

[Bob Gaines]

Alright  guys,
    First thank you,,,,, great feedback, much better than expected,,, im going to attempt a diamond file and belt sand ,, I will post my results here and let you know if break it to pieces,,,, 
   Thank you,,,

We wish you success . I know that your success will help others in the same boat.

[KR Convertible]

Be careful with a belt sander.  Are you going to use a diamond belt?  Anything else would be a waste of time.  As previously mentioned, harmonics are your enemy.  There are more videos on you tube.  Best of luck!

https://www.youtube.com/watch?v=ArQsXIiSRDc

[JohnHouston]

I am sure none of these processes are a walk in the park.  Like everyone else on the internet, though, I'll act like an expert even though I have little experience. 

As was mentioned above, sand along the glass and you can get by with a lot.  Go against it (i.e. at 90 degrees) and you'll make it easy because you'll be finished before you get started.

I once watched a documentary about Cubans keeping old us cars alive.  They would take curved glass from one car, place it on hot steel and recurve it to fit other cars!!!  After the bending, the grinding would begin.  I can only guess how the optics would be! 

Good luck!

[Tired Sheep]

Time for an R model enhancement

[tesgt350]

Have you thought about Polishing the original Back Glass?  There are a lot of products for that.

[poboy427]

Make sure if you are scouting how-to videos that you do not loose sight of the fact that the back glass is tempered unlike safety glass windshields. Most all I found researching was on safety glass. Could polishing scratches out of a back glass be the shorter route? Perhaps, depends on the extent of the scratches. Rippling the surface is a concern if large enough area is not polished. Remember if sanding and polishing on tempered glass with powered equipment was low risk, the service would be readily available I would think.

Ray