I have just recently glued up a 3' x 6' solid hard maple top for a
desk. (Not butcher block style - no end grain on top). I also
decided to try flattening the top via hand planing. So I bought a
Record #7 Jack plane, a Record block plane, and a smoothing plane
(Taiwanese thing). I tried to follow all the advice that has been
posted over the years:

1. First I sharpened the Jack plane iron - I sharpened it first with
a Delta sharpening stone and then, because I didn't like the finish,
went to a 800 grit Japanese water stone.

2. Using the Jack plane (Record #7) I started planing at 45 degree
angle to get the top roughly flat.

This is where I stopped, because I felt I was not achieving the
desired end product. The Record jack plane seemed to slightly chatter
when it caught some wood - it wasn't a nice cutting action. And the
shavings were nothing like when you plane a piece of pine in the
direction of the grain (remember this is hard (very hard) maple). The
plane also did not shave much wood off with each pass (a lot of effort
with no results). When I lowered the blade even a little, the blade
would engage, but dig in and the plane would stop (leaving an
unslightly gouge).

Is my plane blade still not sharp? Is there some sort of test to tell
when something is sharp? If this is the case, what grit/ sharpening
method do you guys suggest?

Also, if I am planing at 45 angle, do I try and plane from one edge to
the other in one stroke? With a 3' wide table top, this is 4.2 feet!
Or do I take short strokes and just work with a quarter of the table
top at a time?

Any suggestions would be appreciated...

Thanks Russ