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Windscreen sealant.

Started by marku, 30 August 2018, 01:41 PM

marku

Any recommendations for this? Finally getting round to fitting the rear seal that I have had for a long time but which sealant to used. Can get little tubes but I want the gun cartridges and I feel I should try to do a proper job.
1974 450SE silver green/bamboo velour/green vinyl roof

daantjie

The one you want is "3M Bedding and Glazing Compound"
Daniel
1977 450 SEL 6.9 - Astralsilber

rumb

If you havent seen already this video by a member is the best instructions

https://www.youtube.com/watch?v=v4hAT0aSIyM

he used 001-989-31-20 window sealing compound
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS
'21 E450 Cabrio

daantjie

Quote from: rumb on 30 August 2018, 03:11 PM
If you havent seen already this video by a member is the best instructions

https://www.youtube.com/watch?v=v4hAT0aSIyM

he used 001-989-31-20 window sealing compound
Absolutely this video is the gold standard, I believe posted by "polymathman" ;)
Daniel
1977 450 SEL 6.9 - Astralsilber

marku

Thanks for that. Video is the right way to do it but it is the rear I am going to do. Did the front some time ago but I am going to have to redo it. Problem was that when I got the car the trim was out for some reason so when I replaced the seal and attempted to fit the trim it didn't sit right. I think it must be bent as it was probably levered out. So I am going to have to take it all out and see if I can bend it to fit the seal profile. Did see in the video that the seal fit the recess perfectly. Mine doesn't even though I got the seal from MB. It is the new type that has the trim under a lip as in the video. Any way as I said its the rear I want to do as I have had the seal for some time. Thanks again for the suggestions for the sealant I was surprised that there doesn't seem to be any around now. Lots for bonding screens in but not for a rubber seal.
1974 450SE silver green/bamboo velour/green vinyl roof

daantjie

#5
Quote from: marku on 02 September 2018, 10:27 AM
Thanks for that. Video is the right way to do it but it is the rear I am going to do. Did the front some time ago but I am going to have to redo it. Problem was that when I got the car the trim was out for some reason so when I replaced the seal and attempted to fit the trim it didn't sit right. I think it must be bent as it was probably levered out. So I am going to have to take it all out and see if I can bend it to fit the seal profile. Did see in the video that the seal fit the recess perfectly. Mine doesn't even though I got the seal from MB. It is the new type that has the trim under a lip as in the video. Any way as I said its the rear I want to do as I have had the seal for some time. Thanks again for the suggestions for the sealant I was surprised that there doesn't seem to be any around now. Lots for bonding screens in but not for a rubber seal.

A tip so you can learn from my mistake ::)  make sure you buy all the clips and rivets which hold the rear trim in place and replace them all once you have the unit out of the car. They will likely all be rusted to hell which makes fitting the trim back a nightmare.

Yes on the front trim if it's bent you'll have a tough time getting it to seat into the rubber if at all. That job is heavy on the prep. If you don't do each step clinically right it turns into quite the "fun" experience...

Also do a quick search for my post on how I did mine. By no means the "gold standard" but you might get a tip here and there. I'll post the link to my post here once I find it.
Daniel
1977 450 SEL 6.9 - Astralsilber

daantjie

Daniel
1977 450 SEL 6.9 - Astralsilber

marku

Very informative. I was thinking of putting the sealant in the seal grooves before mounting the seal on the glass and then on to the body. That possible? The manual is a bit vague and simplistic. Also can't you replace the trim clips after fitting the glass?
1974 450SE silver green/bamboo velour/green vinyl roof

daantjie

Technically yes I guess you could introduce the sealant into the seal before you slip it onto the glass, but the seal can be tricky to get to slip onto the glass, and I suspect if you have gobs of sealant in there already , you are going to end up with a huge mess.  Or maybe that's just me, and you end up using a whole can of cleaner on your skin (not fun, or safe for that matter ::))

I used some dish soap in water to get the seal to slip on, I am sure other members had an easier time to get the seal onto the glass but it really challenged me, so I would suggest to leave the sealant to the end.  If you cut the ends of the sealant tube fine enough then you can slip the tip under the seal to seal the glass from the outside at the end before you put the trim back.  It will ooze out but it's easy to clean on the glass and rubber with some 3M Adhesive Cleaner and rag.  Lots of rags and drop sheets for sure, that stuff gets everywhere!

You can replace the clips after you have the unit back in yes, but it is MUCH easier to do this while you have the unit out of the car.  Then you can take your time to really clean the channel at the pinch weld, and also do some rust touch ups if need be.  If you have to drill out the rivets with the unit in place you can end up damaging the rubber gasket, or worst case crack the glass, so I highly recommend to do this while you have it out.
Daniel
1977 450 SEL 6.9 - Astralsilber

marku

Thanks for the advice just now have to work up enough enthusiasm to do it.
1974 450SE silver green/bamboo velour/green vinyl roof

daantjie

One more tip is to have warm ambient if you can. The rubber is softer then so it's easier to maneuvre. Also the sealer flows much better when it's warm.
Daniel
1977 450 SEL 6.9 - Astralsilber

marku

OK noted. The bottom clips are in a really poor state surprising that they rust so badly.
1974 450SE silver green/bamboo velour/green vinyl roof