Kanger Subtank mini, weld, glue or something else?

[letmein]

What's that brown spot at the base of the main pole, is it a weld or is it glue? If it's a weld, anyone know what it's made of?

Side question: When people clean their tank in boiling water, what do you do to avoid limescale build up?

 

[Katmar]

Bump

 

[Jimi D.]

Could be brass. Boil with distilled water.

 

[BlacklineSoldier]

Well I'm pretty sure that the chimney tube isn't threaded into the top so I'd be willing to bet it was some type of material used to seat the tube. It could be sweated in there, I'd hope they wouldn't use glue on an internal piece. It could also just be built up residue from your juice. Or like someone else said, could be a brass tube.

 

[letmein]

It's never been used, that's why I'm curious what it was. Didnt go away in a wash (dishwashing soap and boiling water).