I was wondering if it is better to make a sanding block the shape of the leading edge? Or can you buy a sanding block to sand the leading edge smooth and perfect? Or do you just do free hand? Thanx for the help.

After rough shaping I use a 3M spounge hand sanding block with 2 diff grits. Seems to work fine for me...

I use a small razor plane to shape the leading edge. Its quick and precise and it only takes light sanding with a block to prepare it for cover.

For most planes... you don't need to be "perfect" about the LE shape. Fun-Fly types (non-competition), sport models and trainers, you won't notive small deviations in the LE shape.

LATER, when building a precision aircraft (scale competition or Pattern aerobatics, or IMAA aerobatics...) you'll want to make a shaped sanding block. The LE shape can be critical for precicion aerobatics, and noteable deviations in the LE of a scale plane can give a major downgrade (plus detracts from perorrmance of HEAVY scale warbirds... messing up your flight score.)

So its not a bad habit to get into to be using the shaped block...

Even if you do get a shaped sanding block, the razor plane that Lou mentioned is a great tool for shaping any kind of balsa....and the shavings are so much harder to inhale than balsa dust!

If you are concerned about a precision L.E. shape, make an accurate template and use the razor plane to shape the L.E to fit. To use a shaped sanding block, the block itself must be a precision mirror image of the desired shape, and I don't know how to create such a precision cavity, especially when you have to add sand paper into the groove and still maintain the accuracy.