Thank you all for your interest and concern re my dent repair experiment. I have been considering this method of repair for some time now and have finally accumulated the necessary hardware. The dent is not a crease but shallow and wide which is why I think this method may work. I have some experience with high hydraulic pressures of up to 30,000 psi when we used to do non-destructive testing of artillery projectiles (once in while, one would destruct). This is why it is important to pressurize only fluid, not air which is compressible and acts as a spring that can do alot of damage if it lets go.
Since many have expressed interest in the results, I'm going to more thoroughly document the procedure and results, to wit, I've added a 4,500 psi gauge to the rig. The hand-pump is rated at 6,500 psi. I'm estimating it will take less than 3k to pop most of the dent but we shall see. I'm in no hurry and I will be very careful.
Jack Romans
Sacramento, Calif