Century cap replacement and top up questions

[Freeman Lowell]

Hi,

 I just received my cap replacement for my Century 100 (thank you Duane K!) and am in the process of preparing (i.e., painting) it for install. My original cap was cracked at the top which I believe lead to evaporation since I’ve owned it (about 5 years). I’m assuming it was just water that evaporated so I’m wondering if I can just top it up to the bottom of the cap with distilled water and how high I should fill it. The cap has been cracked like this for at least 5 years. Any help or tips would be appreciated. Here’s a pic of the current level. 

[Arne]

Yes you can top it up but I can't exactly say whats the maximum. I'm using the bottles for Mathmos lamps of similar design and identical bottle shape so I just put an Astro cap on top and Filled until the gap was gone.

[Freeman Lowell]

Thanks Arne! Did you just use distilled water?

[Freeman Lowell]

This label popped out of the cap too when I opened it up. 

[Cy T.]

Century cap lid print

[Claude J]

the level when cold will show a gap between the water line and the bottom of the cap.
When it's hot (130F) the expansion of the fluid will make the level about the same as the bottom of the cap