Vacuum Dent Puller

[kabulcalling]

When I got the bandit, there was a dent in the tank, on a corner, saddle end - if you will. The dent looks like it is about fist sized. I have been loaned a hand-held vacuum dent puller to get it sorted.
Does anyone have any experience using one of these?
Any preparations to the tank to help prevent paint from cracking?
Do I try to lever up the edges first, or just shove it in the middle of the dent and give it large?
Any advice appreciated.
Cheers,
RMJ

[pebbles]

if it is just a smooth dent give it large if it has a crease
in it then it will not work anyway