For those looking for Borax in Indonesia.. Silversmiths in Bali use pure Borax crystals for flux when they solder. It is usually in a crystalline form, sometimes in powder. You can buy it inexpensively at a jeweler supply store in Celuk in Bali, or Kota Gede in Yogyakarta. I don't know Jakarta, but there must be somewhere there. Sorry, I cannot remember the exact name in Indonesian. Hope this helps.