partitioning - accessing usb drive for storage after making it bootable with 16.04

I used both etcher and startup disk creator to make a live USB to install Ubuntu 16.04 from iso file. I used a sandisk 16gb drive.

I was able to install 16.04 all right. The problem is that the USB stick is now unusable for anything else. It shows only about 1.5gb of storage split into sdb1 and sdb2. Windows formatting does not work. the stick still has the same files and the same amount of storage.

gparted cannot delete the two partitions. The only way recover the disk seems to wipe it with

dd if=/dev/zero of=/dev/sdb