Old Mastic

[john4703]

I built a box out of some uPVC to store some things in my caravan. It was all glued together with mastic. I went the next day to check it and it had fallen apart. The mastic was all soft and slimy. I looked carefully at the tube of mastic, and it was best before March 2016.

I now know that mastic has a use by date.

 

[Deleted member 174758]

We had the same thing with Mirror Mate a few years back - I was supplied with a dozen tubes which were just out of date to fix a number of 3/4 length mirrors behind toilet doors in council offices. The following morning most of them were on the floor. Amazingly not one was broken

 

[freddiemercurystwin]

We had the same thing with Mirror Mate a few years back - I was supplied with a dozen tubes which were just out of date to fix a number of 3/4 length mirrors behind toilet doors in council offices. The following morning most of them were on the floor. Amazingly not one was broken

Did the adhesive just let them kind of slide down the wall rather than just failing outright?

 

[Deleted member 174758]

Probably... They were all OK at the end of the day, but the following morning most were on the floor, it looking like they had slid down the wall, but none were broken. The floor was concrete with vinyl roll covering, so I'd have expected breakages had they just dropped. Most of the mirrors went onto new PB walls which had been emulsioned a couple of weeks earlier and they were installed by four different guys.

When the mirrors were cleaned off (again) and fresh Mirror Mate was applied the following afternoon they all stuck. The newer mastic was quite a bit softer than the old stuff

 

[conny]

Couple of years ago I was asked to throw some tubes of mastic away as they had 'passed their use by date' 6 months ago.
Turned out to be the date of manufacture and they had a shelf life of 3 years. Came in very handy and profitable when a mate needed some for a couple of bathroom jobs he had on at the time.