Procedures

Tackling Rust on the Windscreen Frame


OK. I've finally grasped the nettle (last metaphor, I promise) and decided to tackle the windscreen frame rust on the Aero. It first appeared a few years ago and it seemed like such a big job I kept putting it off, watching it get worse and promising I'd get round to it soon.

It's a common problem on the 9000. You have the windscreen replaced and the monkeys doing the job scrape half the paint off the mounting flange then, without making good the damage, they just bond the new screen on top. With the rubber trim in place, you wouldn't know the difference. Then a few years later, rust starts to appear, usually around the bottom corners of the frame. By the time you can see it, it's already quite bad underneath. By the time it looks bad, it's horrendous.

A pity, really, on a car that is otherwise exceptionally rust-resistant.

Mine was replaced seven years ago when I bought it. The Saab dealer selling the car replaced the cracked windscreen for its first MOT before I picked it up. When I say the dealer did it, it's very likely they contracted it out to some local windscreen monkeys.

I'll show here what I've done so far and I intend to keep posting updates until I have the job finished. It'll probably be week or two as I'm just doing a little bit in the evenings after work.

I should really have taken photos before removing the rubber trim. However, here's what I found after pulling off the trim and flaking off loose rust with my fingers.










I poked around and levered the edges a bit to see how well stuck the screen was. As expected, it wasn't stuck in a few places where the rust had separated. All this poking about led to a few cracks in the screen but I wasn't worried as I was intending to replace it anyway.

Next step was to remove the plastic trim at the base of the screen by the bonnet, after removing the wipers. This uncovered even more tin-worm!








Next, out with the screen to reveal the full extent of the damage.






I expected at least one hole, and there it is...






The next step will be to get rid of the rust and weld that hole (and any others that might appear while dealing with the rust). I'll take the wings off to get better access as it will help with other front-end bodywork I'm going to do anyway.



I remembered you saying, Colin, that you'd had to weld the CSE. I'll probably be looking for advice when I come to do the welding, once I have all the rust dealt with and know how much damage there really is. I've only had a little practice with the MIG.
Then I'll be doing the same job on my dad's CSE over Christmas. It's just showing the first signs of rust around there too.



On the bits that will be covered by the screen and adhesive, I will just paint over any unevenness that is left after rust removal. Anything that will be visible, even by lifting the rubber trim, I will smooth out with a little bit of filler before painting.

Trollbooster wrote:
I ended up weldinf section from a window frame in to replace the missing metal. On balance, I wish I'd removed the screen first.

How did you weld it up without removing the screen? Didn't the rust go underneath?

microcat36 wrote:
If that is the only hole you have and it does not get too much bigger i would just lead fill it Bill, or like i did with one of the more inaccessible holes use JB Weld, it's great for that sort of thing.

We'll see how it goes. The hole will only get bigger as the job progresses and I'd like to weld it properly for strength if I can, although that hole is on a curve (maybe more than one) and might be tricky to do neatly. Still, it will be hidden by the lower trim panel. If welding looks too tricky, I'll go for the epoxy approach (JB Weld or the like). I've never done lead-filling and I'm not sure it's a skill I can be bothered to learn now that there are modern products that will do just as good a job.

Cheq, I'm well prepared to grind away although I might leave the angle-grinder out of it and use a smaller die-grinder instead, especially where that hole is as it is a bit tight for space. For the rest of it, I'm hoping brushing, sanding and then chemical rust removal (rather than conversion) will do the trick. I can see it being quite a therapeutic job getting down to clean metal.

Next job after that will be to obtain a replacement screen. I hope to get a good one from a scrapper at my Saab Specialist. Cutting it out intact will hopefully give me further confidence that I'll be able to simply remove and replace the screen on the CSE when I come to do the same job on that one. And since I can't imagine they sell many secondhand screens, I'm hoping it won't cost me much

I just need to try to get a heat-absorbing one as fitted to '94-on models. If the seal carrier comes out undamaged, even better as it will save me another 30 or so.



It's not an insurance job so would be more like 200 excess.
I no longer trust the b'stards, watched or not. If I do it myself, I know it's done right.

Part of the exercise is also to demonstrate to myself and others that bonded windscreen replacement is not the pro-only job that most people think it is, but is well within the scope of the keen DIYer with inexpensive tools and materials.

I realise I'll probably have to weld quite a big patch to get onto good solid metal. I'm going to use Hammerite Rust Remover Gel. I've had really good results with it in the past. I don't like rust converters as you can never tell whether you've converted all of it or whether there is still some unconverted rust lying underneath out of reach of the chemical. I'd much rather see clean metal.

Obviously, I'll be taking most of the rust off in an abrasive manner before getting the goo out.



I strongly urge you to do it sooner rather than later. If you can see any rust at the corner at all, then there will be plenty of it out of sight.



Well, I'm embarrassed at the apparent lack of progress but I've been doing it in spare time and it actually took quite a bit of work to get this far, mostly down to getting rid of the rust.

Anyway, while grinding off the rust, the holes expanded a bit and this was their final extent.






I continued to grind away the rust. Then applied Hammerite Rust Remover Gel to remove as much of the remainder as possible. This left some stubborn bits in the very pitted metal and I finally gave up trying to remove it and painted it with Hammerite Kurust instead to passivate it.

Then I applied Hammerite Anti-rust Primer to all the exposed metal except the area I intended to weld, which I painted with a zinc-rich weld-through primer.



Then came the bit I was apprehensive about. It turned out not to be too bad because I had ground back all the thin metal so what I was welding to was pretty sound. And the angle grinder made a pretty good job of making a scruffy job look fairly acceptable.



The hole on the left, being a lot smaller, I simply filled with epoxy putty similar to JB Weld but not.



Then I primed the rest.


Next, I'll smooth out the pits on the visible parts with filler before painting. Then it'll be ready for the windscreen, which I'll pick up next week. I couldn't get hold of a second-hand one so ordered one from Euro Saab Parts Direct. It was nowhere near as expensive as I feared. I ended up paying just under 100 for it. Saab price is 150 + VAT and even that isn't as expensive as I thought.



Yes, the bit that the glass is bonded to is covered with rubber bonding so is fairly waterproof. I'm rather grateful mine wasn't as bad as yours. It was more than bad enough for me. I'm rather hping that when I do my dad's CSE it won't need any welding at all. The rust on that one is only just making its first appearance but of course I know now that it mustn't be left to deteriorate.



Good thinking but I did order exactly the right part. I picked it off the EPC for the MY96 9000. The heat-absorbing glass came in for the 1994 model year. I wouldn't be too worried except I believe the ACC sun sensor is different for the two (makes sense when you think about it) so the ACC might have problems with the wrong screen.

It remains to be seen whether the surround comes with it although I do have another brand new one and also kept the original which I removed completely undamaged from the original screen before I dumped it. I think the part I ordered is listed as a kit but I should find out in the next couple of hours when I pick it up.



You felt like crying?
The good thing is that knowing the 9000 is generally very rust-resistant, I was confident that as long as this was fixed properly, I wouldn't be playing "tag" with rust problems for as long as I have the car, which can't be said for other cars I've owned in the past.

Otherwise, I would have despaired.

I've picked up the new screen now but haven't looked inside the box yet. It comes in an enormous box which didn't look like it would fit in the back of a C900 but it fits very neatly



Right, I've just checked out the screen now I've got it home.

Article : Windscreen
PartNo : 7497092
Usage : WITH CUT FOR CH.NUMBER
Heat-absorbing glass
Order Quantity : 1

And it comes with the fitting kit. I haven't unpacked it all but I seem to remember the actual rubber trim that clips into the fitting kit comes separately. I can re-use the old one which is what Saab intend. If that turns out not to fit well, then I can always get a new one.

Mark, the fitting kit you had problems with - was it the universal rubber seal many screen fitters use or was it a third-party copy of the original two-part frame with rubber trim?



A job very well done, Bill, i spoke to a Saab engineer years ago and he told me that Saab knew of this problem by 1993 so you think they would have done something about it.



Well, it's not done yet but I can see it has a chance of turning out well now. It would have been nice of Saab to try to address the problem in 1993. As I said earlier, the windscreen on that car was actually replaced by (or on behalf of) the dealer I bought the car from in 1999. A bit rubbish if you ask me. It would have been better had I not ignored it for years but I think I'm better-equipped to fix it now than I was when it first started to show.



Rust around the windscreen is something i've been dreading on my 9k aero. I remember about 15 years ago when my dad had the windscreen replaced on an early C-reg 9000 turbo, and within 2 years there was no sound metal atall on a strip about 18 inches beneath the screen as it meets the scuttle. I think the early 9000s were probably more rust prone, but it was scary. He always put this down to the fact that at this time the windscreen places were less used to dealing with bonded screens, but probably experience has nothing to do with it.

My car has quite a few chips in the windscreen, and i've forced auto windscreens to repair them under the insurance rather than replace the screen, I just don't trust them to do a good job. Has anyone out there actually asked to supervise the job, or at least see the state of the surround before the glass is put back in? I would think that this is a reasonable request given the possible consequences! I think that this is what I will do when the inevitable happens! That is assuming it is on its first screen??

Good work btw Bill, always the best way to do it yourself, especially when patience and hard work are necessary to do a good job!



Perhaps you could find a friendly body-shop who are willing to let the windscreen-bodgers remove the screen on the premises. Then if any work needs doing to prepare it properly for the new screen they can fix it and the bodgers could come back another day to fit it.

I do like the idea of knowing exactly what's in there after I've done the job. That's the benefit of doing it yourself as well as the obvious one you pointed out of being able to put in as much effort as it takes to do the job right. No body-shop or windscreen bod will care more about my car than me



Right, it's looking like I only get to make any progress on this at weekends but at least I'm nearly there now.

The painting stage.
Instead of using a spray gun, I decided to use aerosols to minimise overspray and therefore the need for masking. I've seen this job done with aerosols before on a 9000 in the same clour and it worked very well. My spray gun will easily fill the entire garage with overspray

I went to Halfords to get them to mix a can of Saab 247. Their computer wasn't working so they had to call another branch to ask them to look up the recipe. The young chap wrote it down then checked I wanted a 100ml touch-up. No, I said. I'd asked him for a 300ml aerosol. So he had to multiply all the numbers by 3. He seemed to be struggling a bit with doing them in his head and when he got to the last one, he seemed to be having a lot of trouble so I did it for him. Then I asked if he'd mind checking it on a calculator and he obliged. It turned out the only one that was right was the one I'd calculated for him

Anyway, he thanked me for making him check it and set about mixing it. Then he got stuck again when he couldn't find one of the colours. He called the other branch again and it turned out he'd written it down wrong.

Eventually, we had an aerosol full of paint that looked like it might be the right colour. Plus a freebie 100ml touch-up because it seems he mixed too much.

So, back to the plot. I've filled the pitted bits and primed over them, then applied the silver base coat and the clear lacquer. The Halfords/Holts aerosol turned out not only to be the right colour but also to be really nice to use, although the spray pattern is quite wide for an aerosol - an advantage for most situations but a bit of a drawback for this job where the bit I'm painting is fairly narrow. I brush-painted the parts of the frame that will not be visible, partly to minimise overspray and partly to give a fairly substantial protective coating.



The passenger-side pillar only needed painting to about two thirds of the way up so I had plenty of room to blend the colour below the roof. The transition is just about invisible to the naked eye.



On the other side, I had to paint quite close to the roof so had to mask it to avoid spraying onto the roof. Even though I used a "soft" mask line, it's still visible. The lacquer transition should disappear once I cut it back and the rest shouldn't be noticeable under normal conditions because so little of the pillar is actually visible anyway.



Now all that remains to do (on this particular job, anyway) is to fit the new screen and Waxoyl the frame from the inside. I don't suppose it matters which I do first, does it? I may do the Waxoyl last of all and also run some around the edge of the screen before fitting the rubber trim, in an attempt to minimise the chance of a recurrance of the problem.



I was thinking I ought to get an airbrush. It would be ideal for this sort of job. The mismatch on the driver's side actually looks a lot worse in the photo than in real life so I'm quite pleased with how it's turning out.



Thanks, Jim & Martin. If I get a chance to work on it, then sometime this week. If not, then definitely by next weekend. I don't see it taking much longer now. All the slow stuff is done. This weekend was largely spent waiting for paint or filler to dry

I'd like to leave the paint a few days to harden properly before proceeding.

I just hope it lasts after all this



Right, almost the final instalment for this particular job.

This is what I got from Saab for less than 100



It includes the metal windscreen surround but not the rubber weather strip and, irritatingly, not the metal clips to cover the join between the two halves of the surround. Luckily, I had had the forethought to keep the old clips and I just painted them to make them look as new.

I sanded the new paint on the flange of the frame slightly with 400-grit to key it for the following procedure.

The adhesive I used was made by Dinitrol. In looking around for windscreen adhesive, I found very few sources. It is possible to buy a single canister of it (enough for one windscreen) but it is quite expensive (25-30). Since I intend to repeat this job on another 9000 shortly, it was cheaper to buy a pack of twelve from Rejel Automotive for 37.90 + VAT. I can't recommend this company highly enough. The majority of their business is with the windscreen replacement industry but they were very happy to deal with me as a private individual and even to allow me to collect the goods personally once I realised they were only a few miles from my home. They were helpful and friendly and I will certainly be using them again.

The following procedure may be specific to the Dinitrol product I used but I imagine it must be broadly similar to the procedure for other products. The cleaner/activator and primer are supplied with the adhesive.

The first step was to apply the glass cleaner/activator to the windscreen.



When dried, I wiped it off with a clean cloth and applied the primer. This must be applied to the glass and to any bare metal or paint on the frame. Old adhesive on the frame should be left un-primed as the new adhesive should bond to it very well. The primer dries to a rubbery finish, similar to the adhesive itself.





Next was to fit the metal trim around the edge of the glass.



The trim is a good tight fit on the glass. I tapped it home with the palm of my hand. The gaps are normal. They will be covered by the metal clips (not included, although I'm sure they should have been).

There are four rubber spacer blocks supplied in a plastic bag.
Two right-angle ones to space the screen from the bottom of the frame and off the flange...



...and two flat ones to space the top of the screen off the flange.



Getting there.
I applied the adhesive in a thick bead. The nozzles that came with the adhesive were pre-cut. A fairly thick bead all the way round used about 3/4 of the canister. This was very hard work with a cheap caulking gun as the adhesive is so viscous. I may well invest in a better one for next time. Having the luxury of a compressed air supply, I might go for an air-powered one.



Finally, the satisfying moment!
I couldn't photograph the fitting of the screen as I could barely manage it with both hands. The 9000 is quite a wide car. It would probably have been easier if I'd placed the handles closer to the centre. As it was, I sat on the wing (well, where the wing would be) and managed to reach over far enough. The screen isn't terribly heavy but this would be easier with an assistant.





Yes!

Having the pillar trims and dash top removed, I was able to inspect most of the bond from the inside. It looked OK. I really hope it doesn't leak

I found that any stray adhesive on paintwork was easily removed while wet using a cloth soaked with white spirit. I suspect it would also "roll" off when cured. The whole procedure took about an hour.

Tomorrow, I'll fit the clips over the gaps and clean up and refit the weather strip. Then I can get on with the other, less urgent jobs.



Thanks, guys. I must admit to being well pleased with it. I fitted the clips and weather strip this morning. The strip is flexible plastic rather than rubber and is a good tight fit into the slot in the frame. I used the handle of a screwdriver to push it in. I was worried that it would have stretched and not fit properly a second time but it was fine. I do have another complete fitting kit, including surround, clips and weather strip, that I bought from Rejel for 35 all-in but I'm saving that for one of the other cars, neither of which has a good, original surround.

So here's how it looks.



Once the wings and scuttle-trim are back on, I don't think anyone would know the difference.






By the way, I missed out a step from yesterday's write-up. Before I refitted the screen, I sprayed Waxoyl underneath the bottom of the frame and as far up the inside of the sides as I could get. There is a piece of foam either side that needs to be removed for access. I had already removed the one on the passenger side while removing and welding up the rusty bits.



Cheers, Kevin. On both counts

It is optional as to whether to put the goo on the windscreen or on the flange and I decided to put it on the flange for convenience (feasibility )
It would actually be easier to apply it to the screen but this gives no margin for error while fitting it, meaning it would really be a two-person job.



I actually managed to do this on my dad's CSE but it was a bit of a bodge. I only persevered because the third-party strip had already been hacked about and looked awful. The two halves of the surround clip onto the edge of the glass and you probably won't have enough room around the glass to do this in situ. You could grind the rear face off the surround and fit it to the front of the glass with epoxy. Other than that, I think the only way, really, is to have the glass out.

I took my CSE to a Saab specialist earlier this year to replace a cracked screen. I assumed they would fit the proper Saab surround but they (their windscreen contractor, actually) refitted the old third-party strip. I was quite annoyed. Once I've done my dad's, I'll probably do that one too, partly to replace the strip and partly to refurbish the frame before it goes the way of the other two.



Further to this adventure, Mark P and I tackled the same job on my dad's CSE over Christmas. The differences from last time were that we only had a couple of days to do it and the car was going to head off hundreds of miles away afterwards so it had to be right first time. And we had my previous experience as a guide, of course.

Mark took a load of photos so I thought I'd whack them in here to supplement the previous record.

We took the windscreen out (with very little effort and completely intact) and saw this. I thought "not again!"



Mark got stuck in with a wire brush in the air grinder and did a really impressive job of cleaning it up. Much more thoroughly than I did on the Aero.



Applying the adhesive was a lot easier this time because we used a power caulking gun and applied it to the screen instead of the frame since there were two of us to line it up while fitting it.



It certainly seemed to work OK and appear to leak at all even after it sitting out in the rain and then being washed with copious amounts of water. Very satisfying work.

A big "thanks" to Mark who really put his back into it and made the whole job a lot easier.



Happy new year, Kevin!

There were some holes. Not as bad as the Aero so we filled them with epoxy putty. I suspect part of the ease of getting the screen out intact was that it wasn't very well bonded in the first place. In fact, it had been leaking at the driver's door pillar where it seems the adhesive bead began and ended. If you look at the first photo of the bottom passenger corner, you can see how the original bead was. Not very substantial. Also the tool we used to cut the bead seemed to be a very good tool for the job.

I had already bought a new screen as the previous one had been in the car since before I bought it 4.5 years ago. It looks like a cheap aftermarket item (like the fitting ) without the VIN plate window and almost certainly not heat-absorbent. The screen that went in was another genuine Saab kit from Euro Saab Parts Direct, although this was a few quid more than the last one as they had none in stock. Still came in at just over 100 all-in, though.