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MG Midget and Sprite Technical - Fitting New Glass Into Widscreen Frame
|My Sprite was reshelled by a previous owner and whilst virtually everything was restored or replaced there are a few bits and pieces that are original. One of these is the windscreen glass. Even though it is perfectly serviceable there are a few chips. I note a new glass isn't too expensive. How difficult is it to fit a new glass and rubber into its frame?|
|Jan, I forget which model Sprite you have. If it's a wind up window model then replacing glass is easily done using small ratchet straps to gradually close the frame sections onto the glass (and then again later to pull the whole assembly down onto the scuttle).
On earlier Sprites I think fitting the rubber between glass and frame is a bit harder, but still a DIY job, with lubrication and patience!
But price up the seals as they can come to almost as much as the glass itself!
Nigel will(rightly) warn of poor rubber which doesn't last well, or is of the wrong profile. But never seems to come up with any positive suggestions to get round that. The usual "only buy from a well known supplier" doesn't seem to guarantee success either!
|'If it's a wind up window model then replacing glass is easily done'
Sounds a bit 'Haynes Manual' to me !
It can be a right mare of a job - I've done a few midget and similar 'B' ones, corroded screws (some needing drilling out and rusted out corner brackets come to mind.
When I put mine together I add a little of the special windscreen mastic (black and easily cleaned up with white spirit) at the lower corners of the frame before fitting the seal into place - the original factory seemed to have a hard putty type stuff in this location - where water could seep down.
When refitting to body I again add some of the mastic below the pillar seals etc.
The other issue is if you replace the scuttle seal, it needs to be persuaded to sit outwards but its shape naturally rolls underneath - I use a cord and a hard plastic tool to act as a pusher from behind - like a plastic shim with a rounded leading edge.
Refitting is easier with an assistant to push down on the centre of the screen - not tried guys strap method.
Windscreen glass replacement - that sounds like a job that requires patience and luck to avoid cracked glass, grazed knuckles/blood and swearing! And a good quality pliant new seal of the correct dimensions with suitable lubrication for you and the seal.
I bet if I had a second screen it would go smoothly, but if I only had one good one to swap I would crack it!
|I've done 3 on later style screens. My 1500 and 1275 cars and a friend's mk3. All went pretty smoothly. I use 3 ratchet straps, 2 vertically around the screen about 1/3rd in from either end, and one across the width.
Put the rubber around the glass and position the frame pieces so the rubber is aligned with the slots and then hold it all in position by lightly tightening the straps. It helps to have 3 or more hands for this, though I did it alone. add some frame sealant in the corners as Richard said and brush on some lubricant and then gradually tension the straps, tweeking them just a few clicks every 10 minutes or so, but between times just leave it and the rubber seals gradually creep into the frame slots. Eventually it all comes together and the corner screws can be fitted.
|It can also be difficult to get the side stanchion bolts into their holes when fixing the assembled frame to the car. Again I use ratchet straps hooked around the upper door hinge to pull the frame down onto the scuttle. I recorded that method with photos of positioning ratchet straps quite a few years ago and the photos still pop up from time to time now on facebook, which I don't think even existed at the time!😁|
|Would be good to see those photos Guy, I recently refurbished the windscreen and used straps to pull the frame down but the bottom rubber seal isn’t pulled down enough probably due to the thickness of the two bottom corner rubbers, would be good to see in pics how you’d got those straps.|
|Tim, I will see if I can awaken the now never used desktop computer that I used at the time. Photos should be on there. I know that the pull down angle with the ratchet straps wasn't quite perfect, but using the top door hinge was as near as I could get. But it worked to pull the screen down far enough to get the stanchion bolts in, which was the main challenge at the time, especially as I invariably work alone on these things.|
|Thanks Guy, getting the correct angle with the ratchet straps was not easy and finding an anchor for one end was difficult without damaging any bodywork, unfortunately not totally succesful, but trying the door hinges next time sounds a good idea.|
|Here you go Tim. Use of ratchet straps to pull the frame down onto the scuttle for aligning stanchion bolts. |
The webbing strap goes under the top door hinge and the hooks and ratchet device lie against the alloy of the stanchion to avoid scratching the paintwork. I guess I could have put a bit of raf or cardf between then an the stanchion as well, though I clearly didn't think of that at the time! As you can see one can get a pull which is not quite, but very nearly, aligned straight down the pillar.
How far down will that pull the screen and frame down? Does it need to go all the way down to the bottom of the slots for the 4 bolts?
Will that solve my issue of one vent window frame nearly perfect and the other interfering with the closing of the door without the seal?
The doors were challenging, this is much more frustrating.
|Hi Steve, yes, the ratchet straps like that will pull the screen down, compressing the rubber seal under the screen and under the stanchions. It should go tight enough down to get the bolts started that hold the stanchions in place - 2 each side. Once those are located, but not fully tightened, you should then close the doors and tilt the screen forwards or backwards as needed to align and position it parallel to the leading edge of the door quarterlight frames. Then tighten the stanchion fixing bolts.
If one door window frame is fouling the windscreen will the screen push forward at that side (bolts loodsened) or is it at the limit of adjustment? The quarterlight frame also has some adjustment where it fixes to the door, and especially at the L or U shaped bracket which steadies the bottom end of the front channel piece, down inside the door. Have you tried that?
Here is a few answers and a few more questions....for you.
I can get the bolts in without any issue. However when I ratchet strap it down to further compress the new seal the windscreen goes into the cockpit, I need it to go out towards the engine to allow the quarter light to clear.
Yes from what I can tell the frame is all the way forward....
Should I ratchet strap before fitting the bolts? Maybe it is just all binding on the bolts instead of sliding down?
Yes I have the quarter light/vent window kicked out and away from the vehicle to allow for more space.
|I don't really remember, other than when I have done them the hard part is usually getting the screen tight enough down to get the bolts through their holes and started in the threads. At that stage the rubber seals are already pretty well compressed. I think I got one bolt in at each side and then pushed the screen forwards to get the angles right, using those bolts as fulcrums, before getting the second bolt in at each side.
(is one a bolt and the other a stud? Or one a bolt into a threaded hole in the stanchion and the other a nut and bolt? - I forget)
I have done this on several occasions now and the screen stanchions have never been very far out at first attempt, so I am wondering if your door frames are maybe not correct?
I appreciate the chat today!!!
I used a drift pin in the lower hole to get the top Bolt/Screw no nut in.
I did that on both sides, then I used a rubber clamp to push down to get the lower nut and bolt in. I have since been struggling to get it even without stressing the glass (original) I did replace the seal...that was fun!
I will try just rocking the screen forward and cranking it down.
I'll update this thread that I "borrowed"
|Steve, the other thing - I had forgotten - there are or may be a number of shimms to go in where the stanchion legs abut the body frame. Several shared between the two sides to help centralise the screen. Do you have those?|
|OK, I think I was thinking I had to pull the screen down even more!!|
4 Bolts in quarter light/vent windows look good, need to re adjust the RH side Vent window angle and I think I am good besides the two screws for the center of the dashboard.
Thank you Guy!!!
This thread was discussed between 19/07/2021 and 31/07/2021
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.