Re: how much is enough
here is the tool Im using. it works good.
You can get both hands on it and the blades are replaceable.
Its actually a 2 sided blade so you can flip it and use it again before you need to replace it.
its that other tool beyond the hammer in the picture with the black handle and black knob on it.
the right side of the picture is scraped, the other side is not.
That should give you an idea of how much needs scraped.