Originally Posted by Manton
Can you use the stone to restore the tip of a knife that got bent? And if so, how?
it depends, but generally the answer is not very well. Please tell me this was not one of your Shuns, BTW.
If the bend is only in the bevel (i.e. - not deep at all), then grinding it away is your best option - just establish a new bevel and go from there. I'd grind away the bent portion on the side of the stone (think: like the spine of a book) to avoid gouging the stone's face. Grind it until flat, then re-establish a new bevel and pay close attention to the sweep of the edge - you'll have taken off a bit of metal and will need to re-set the curve so your knife cuts gracefully from heel to tip. This should not be much work, though.
If you've kinked the knife (or creased it) - I'd send it back to the manufacturer to see about either replacement or if they can re-forge it back to straightness. An independant blacksmith can probably do this as well, but in any case it's quite spendy and your satisfaction is not guraranteed.
If it's a gentle bend into the steel behind the bevel, you'll want to straighten it by other means - If it were my knife I'd try a vice (lining the jaws with scrap leather) and gentle pressure to flatten the knife, but this may not work depending on a number of factors (hardness, springiness, etc.). Failing that, a heavy hammer (safety goggles are a must!) and anvil should straighen a mild bend, but again it's not a perfect solution. Once you get close, flatten the sides on the waterstone and then re-sharpen.
If these don't work, and you still want to salvage the knife, I'd take it to a bench grinder to grind away the tip and re-set the curve. It will work much faster than the water stone, but you'll need to watch the knife to make sure you don't overheat it and draw out the temper. You'll have a shorter knife, but it will still be useful.