Removing hard water buildup from CA tea kettle ?

[Phil Kenyon]

Maybe the cleaning and restoration section was the wrong place to ask so I'll try here .
 Over the many years of sitting on a hot wood stove with water in it this kettle has a lot of that hard mineral build up inside.  Is there any way to safely remove that stuff ? I am worried about creating pin holes or cracking the aluminum if I heat it dry and/or take putty knife or chisel to it. I don't have a pic of the inside but , it is 1/4 " - 1/2" thick in some spots.
Here is the outside of it :

[John Wright]

You might try boiling white vinegar in it a time or two.

[Cheryl Watson]

I fill my tea kettles with White Vinegar, full strength.

And boil it, and boil, and boil.

Aluminum requires frequent checking, even more so than CI.

[Phil Kenyon]

 Thank you , I will try some vinegar when I get a chance. Still worried about getting little pinholes so I'll go easy on it.