Sikafex 291i or CT1 for sealing glass in hatch?

[Clodi]

All I have onboard is a tube of CT1 or Sikaflex 291I & I need to refix the glass in a sidehatch. The seal is against the external steel of the hatch & I want to get the glass in before the next rain. I'm not going to get to any suppliers of window tape which I use on the portholes.. I know the Sika flexes but I've never used the CT1.

What to use?

[jonathanA]

291i seesm to be for 'interior' use which makes me wonder about how durable it would be for sealing glass in an exterior situation.  CT1 seems to be something of a 'wonder' product but does seem more suited to damp/wet situations.  

 

my guess is either would do the job its probably about how long they last/when it starts looking tatty.....  would you be able to get the glass out again without damage if you needed to - again i suspect you could with either (with care) so worst case you can redo it at some point in the future if you need to.  

[blackrose]

Are they both clear? If not I'd use something clear like Stixall which would be fine for the job. Clean all surfaces to be stuck with a bit of white spirit first.

 

https://www.toolstation.com/stixall-adhesive-sealant/p77137

 

If your CT1 is clear then I'd use that. 

 

 

[Chewbacka]

Don’t use silicones as they will need very careful removal if you want to remake the bond in future.  For long life - say more than 7 years you need a glass primer on the glass, something like betaprime 550 is good (available on eBay & Amazon). This is often used for car windscreen replacement.  Without using a primer the bond may fail after a few years.

Also don’t push the glass in too hard, you need an adhesive thickness of a few millimetres otherwise the stress from temperature expansion  mismatch will cause the joint to fail.  I would use alcohol (ipa) to clean the surfaces.  A good way to check if your solvent (eg white spirit) is ‘pure’ put a drop on the glass, leave to dry and if it leaves an oily residue don’t use it.

Edited June 15, 2023 by Chewbacka

[Clodi]

Thanks all, I only have the 2 tube i mentioned, I think I'll go with the Sika & see what happens. I need to do it today as we have rain forecast for tomorrow.