I’ve had a bottle of Stan’s sealant in the kit box for 6-7 years – seal unbroken, just never got round to going tubeless. No expiry date on the bottle, seems to be sloshing around inside. As someone who’s never really paid much attention to tubeless solutions, my questions are:

Does it go off if unused?

Has sealant technology moved on so much in the last 6-7 years that, even if it’s in tip top condition, I’d be better off buying contemporary sealant?

I had a bottle of Joe’s No-flats which I lost in the garage for at least 10 years. Still worked like brand new.

No doubt some sealants with different ingredients don’t last as long but if it’s still liquid just go for it.

Give it a good shake first!

Should be fine if it’s not been exposed to the air

If it was 10 years old it’ll only work in 26″ tyres though

I would shake several times and leave it alternately upside down, right side up for a few days to ensure all the sediment is mixed into the solution and not caked at the bottom of the bottle. And then stick a screwdriver in there to check. If it’s congealed then it won’t be very effective at sealing a puncture.

If it was 10 years old it’ll only work in 26″ tyres though

Don’t be silly, it’ll work perfectly fine on 29’ers so long as the tyres are no wider than 2.2″ and the HA is a maximum of 71deg, there’s no chance it’ll work on 27.5″ though or anything with a BB below the axle line 😀

In a way it is changing wheel standards (hookless rims, tyre construction) that are pushing me down this road to a solution for a problem I’ve never really felt I had (although I understand there’s more to tubeless than just puncture prevention).