Hi Kieth
Is the "down to white" under paint of your tank or simply the lacqure?
If under paint of your tank you need to touch it up but if lacqure you can do as Chris or Lazarus suggest.
In either case you first need to:
1 wash tank
2 Clay tank (Mags do a kit, this removes all wax and any service contaminents that you can not see but will make your task harder if not worst by spreading it via swerls)
3 Auto glym but very lightly
4 Mags 1, 2, 3 step
5 Use detailer you got in clay kit to give it a deep shine
This is how I do my car. The pics hopefully show you the results of appliying by hand. I used pads to apply product but never use the same pad for all products or it will go tits up. Buff and clean off inbetween of products using different microfiber cloths.
all the best with it mate
Daz
 1 Before scratches scuffs nearside rear wheel pannel |
1 Before scratches scuffs nearside rear wheel pannel |
 2 After hand applied products elbowgrease |
2 After hand applied products elbowgrease |
 3 Before nearside corner pannel |
3 Before nearside corner pannel |
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4 Before nearside pannel |
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5 After nearside pannel |
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6 Nearside end result |
 7 The products applied by hand |
7 The products applied by hand |