Resealing headlights Recommended mastic?

[Horsey McHorseface]

When I separated the glass lens from casing, I scraped off the surplus black mastic, because the plan then was to replace it. Now I'm not sure that was the smartest move, because the option was there to simply reuse the existing mastic, to reseal. Not sure I have sufficient mastic leftover now, to properly reseal?



Anyhow, I've been recommended this:
Soudal Soudaflex 40FC Polyurethane Sealant / Adhesive, Black, 310 ml

Any other recommendations?

Edited by Horsey McHorseface on Thursday 30th July 19:31

[redbulletv8]

I'd go for a polyurethane too, much better than trying to use a mastic or RTV, just make sure you don't get it inside the lamp where its not needed as its a bugger to get off.

[Horsey McHorseface]

redbulletv8 said:

I'd go for a polyurethane too, much better than trying to use a mastic or RTV, just make sure you don't get it inside the lamp where its not needed as its a bugger to get off.

Noted. However, I already ordered this, 20 minutes ago: https://www.amazon.co.uk/sealant-Diameter-Automoti...