Maximum voltage/wattage on glass globe attachment?

I have one of those 510 thread ceramic nails with a coil in the middle with a little glass dome that slides over it. I've been using it with an ego battery for awhile and it works pretty well especially with the cannastick bubbler attachment, but I just recently put it on my iStick 30w at 7.5 watts 3.7v with the coil reading 1.8 ohms. It produced a lot more vapor but I'm afraid I might burn the coil out if I keep vaping it that high. Does anyone know the highest voltage these can take consistently without risk of blowing?

It's gonna blow as you put it eventually no matter what hence why they sell the coils new... but yes the more power you apply to it, the faster it will degrade, but in most glass globe attys, you'll never get the chance to degrade the metal before the silica, which most attys still choose for whatever cheap reason, I posted a nice new glass globe atty in the one hitter quitter thread that actually managed to get 2 (fc200?) ceramic rods in dual coil setup in replacement of silica. Now that baby should last a while, even being abused... so if you can find replacement attys with the ceramic, you can fit it in your globe attys, tested it already they are the same size as the original.

Cool man thanks