Adhesive query: Steel to rubber to glass

I am repairing a wind-up window in an old car. The bottom edge of the glass is trapped in a thin folded strip of steel*, with a thin moulding of synthetic rubber between them. The glue used by the previous owner was black silicone, and it had worked fairly well, except that there was rusting between the rubber and the steel - which I guess was caused by the acetic acid from the sealant as it cured.

There are lots of more modern versions of 'glue' now, and I wonder if a polyurethane product would be better? Or a Loctite might be better still? Perhaps superglue might cause problems, as the glass has to be pushed carefully into its rubber-lined slot, and so a slow-ish cure would be best.
If you have experience which worked well, or didn't, please tell us - thanks.

* the steel strip is welded to a thicker strip, slotted for the lifter chain, in case that helps work out what is going on. And the chain is a 'block chain', and nothing to do with fancy ways of losing money.

Seasonal greetings to you all

Regards, Tim

Edited By Tim Stevens on 16/12/2022 15:44:42

Hi Tim

I have heard very good reports that "Tiger Seal" is the best product for this application.

I have actually got some myself, but not had chance to try it yet.

Phil

I cannot help you Tim, but I must say I like your "No nonsense" approach to the problem !!

Hi Tim

PU adhesive / sealant woud be my choice. Sikaflex EBT+ available from usual suppliers including B&Q & Screwfix, is what I use personally.

Tiger seal is a simlar product.

Robert G8RPI.

Sikaflex 255FC would be the obvious choice, it's tensile strength (6MPa) is quite close to that of a typical Glass (7MPa) which means it gives about as strong a bond as is possible without being so permanent that deliberate disassembly would result in destruction.

The only caveat would be: If you can lay your hands on an individual cartridge rather than having to buy a full case, given it's mostly sold to automotive manufacturers and coach-builders, it's not easy to come by.

I was going to look up the two Technical Data Sheets to see if the performance characteristics were definitively better than Tiger Seal (I have been told it is significantly better by several sources, but talk is cheap), unfortunately whilst the Sika TDS is very detailed, the U-Pol TDS doesn't actually give any technical data...

Faced with the same situation myself on an old Citroen C15 window for a friend, I just used some fresh rubber packing, and progressively closed the channel up onto the rubber and glass using a press to apply force slowly and carefully.

The result was just like the OEM assembly, with no adhesives required, and has been in service 5 years so far with no issues (well, with that window, the chassis, cills, engine, gearbox, speedo and lights are all another matter).

Edited By Jelly on 16/12/2022 16:27:07

as Jelly said manufacture did not use any adhesive

It depends on the condition of the pressed part in fairness, we were lucky in that my friend had managed to source a large amount of different rust free parts (from Blackpool of all places, not sure how that one works out) the window channels amongst them.

Faced with trying to re-use salvaged channels, at least one of them would have been simply too corroded to take that approach with, and we would have had to use an adhesive (or try to fabricobble something from a pattern part for another vehicle and the original with a spot-welder).

I would use this stuff having seen the price of a 3M tube or chat up a windscreen repair guy, after de rusting and Galv (zinc) spraying the offending channel.

I use CT1 for any tricky glueing or sealing jobs, good stuff.

pinkgrip

As said, adhesive is not normally used and is not necessary. .

The glass is a simple press fit into the rubber channel- lubricate the rubber to make it easier.

Edited By Redsetter on 16/12/2022 20:21:50

The question does not relate to a modern car with windows that are fitted from the outside. To replace the glass (as I am doing) requires the removal of two leather panels, held in place by tin-tacks, and covered by a leather strip, as well as the removal of a wooden upright from the hood mechanism. Then the wooden panel which holds the lift device has to be destroyed because it cannot be removed, and a new one made. So, you will understand that I do not wish to do the job again because
a) a joint designed for a pressed steel car is not in use, and for which there is no evidence that it will last in a 1928 body made of worm-eaten forestry products, and
b) because it is a seriously long job.
The steel-rubber-glass joint in question is about 5 inches long, (127mm) and the glass it holds is about 12 x 20 inches (300 x 500mm), so any comparison with a complete windscreen which actually fits all the way round is not reasonable, either.
But thanks to those of you who suggested that a polyurethane adhesive should serve well - as used for sticking mirror brackets to the backs of modern windscreens. All being well, I will report on progress, but ...

I will not be able to report on the strength of the finished job, as the recent failure was caused when the closed touring hood lifted from its catches on the screen as a truck passed me rather close. And Ii was doing about 60 mph into a head wind. As far I am am able, I intend that to be a once-in-a-lifetime experience.

Off to the Builder's Merchants tomorrow to see if anything useful comes in a smaller tube than is needed to reglaze a row of houses.

Thanks again - Tim

When we used to fix these in the 60s and 70s no glue was used the rubber was stretched and because of this it made it thinner allowing the winder rail to be pushed over the rubber onto the glass and when the rubber was released it made the whole thing tighter. Wouldn't mind a pound for every one done!!!!

As Ebenezer has said CT 1 sticks almost anything, you have a choice of colour and once opened if kept sealed has a good shelf life. Noel.

Me too Bernard

Keith.

I may have found a product in a smaller tube - but with the same properties;

Everbuild Stixall. This is described as having properties of silicone and polyurethane, and includes two chemicals which I can neither pronounce or spell.

Knowing a little about the way inductry works, my guess is that there are three or four firms which supply the UK building trade with stuff in tubes, and Everbuild is one of them which serves the Welsh Border.

And it says it sticks 'virtually everything' - so maybe it is CT1 in disguise. But if you know different ...

Regards, Tim

Good evening all.

For Oddball adhesives, I highly rcommend Advanced Adhesives in Newcastle. I made the most over engineered pepper grinder out of solid A316 for my ageing parents a couple of years ago, & a similar coffee grinder. The internals were made of polypropylene. Advanced Adhesives recommended a two part glue which did the job perfectly.

Cheers.

Stewart.