I can empathize with you. And sometimes it is interesting to do something
just for the challenge of it, if no other reason. So go for it, and you
will learn a lot. A couple of questions.

First, do you have a reference surface that is flat? Usually a granite
block, these things cost significant $$ but are the real reference in
machine shops where a "flat" surface is required. Without that reference,
your straightedge is probably off by more than your desired flatness, unless
you have some specialized tools.

Second, what is the ratio between the area you are trying to flatten and the
thickness of the piece? Keep in mind **everything** bends -- it's just a
matter of degree how much. Unless the ratio less than about 3 (three times
as long as the piece is thick) you shouldn't expect to hold a surface flat.
How do you judge the flatness of a peice of cardboard? It bend when you
pick it up. Look at the backing of optical mirrors -- they are not just
left to flex as they wish.

Third, how big is the flat surface? If you want a area of more than (say)
6x6 inches, in wood, good luck. If it is 2x2 inches, you will have better
chances. In big pieces of wood, the material rigidity and stability just
are not in favor of your success. Stuff that can be made flat -- and stay
flat -- is usually stiff and brittle: not the description one would apply to
wood. This is why flat surfaces on machines are often cast iron, not steel.

Keep us posted.

Matthew


"Bob" wrote in message
om...
Hello:

I have struggled to a point way beyond frustration to get a surface-
any surface dead-on flat. I have used the marking the high points
method and used every plane scrub, jack, jointer, smooth, scraper,
etc., No matter what I do I can't get it 100% flat. When I shine a
light behind my Starrett, it is always off by a few thou. Is there a
way to get a surface truly flat using hand planes and a scraper? It
almost seems impossible. What am I doing wrong?

Thanks!

Bob