First thought is to consider how stable it will remain.

Do you need to add some sort of battens, or dovetail some supports in to the
base to keep it flat after you’ve worked on it?

Next thought - Old time folk wouldn’t necessarily flatten the underside.  If it
is to rest on bearers across the top of the unit - then just provide trenches /
rebates where the bearers run, and leave the excess timber in place.

That gets us to the top. 

Now - the reason for using a slab must be that you want the single piece look.
Ass soon as you rip it to reglue, then you lose that, so I can see why you would
want to flatten it.  The attraction of a large slab, in one piece, is not to be
given up lightly - that slab of walnut we just looked at? - criminal to cut that
up. even if you reglue it together afterward.
So we need it to remain stable, otherwise we’d just rip it and reglue.  but it
decided to cup whilst drying.
Will it do so again?
What’s its moisture content now?

can you leave it in the kitchen to acclimatise for a year?   a month?  couple of
months?

Will you be doing this every 6 months?  Is it going to split as it dries
further?   How do you minimise the chances of splitting?


More questions than answers here - sorry.  Apart from ‘don’t bother with the
underside’ - even to the extent of running a rebate around it and fixing a skirt
to hide the gaps…


Richard Wilson
Yorkshireman Galoot.  where the sun has decided to shine now I’m indoors after
it’s done ’sprinkling’ on me



> On 4 May 2021, at 03:41, Andrew Heybey  wrote:
> 
> We recently redid our kitchen.  There is a small island in the kitchen, the
top of which is about 3’ x 3’.  A friend gave us a large slab of beech to use as
the top of the island.  The slab is is about 36” by 45” by 3-3.5” (it tapers
from one end to the other).  It is also bowed by about 1/2” across the narrow
dimension.
> 
> My first shameful thought was to rip it into 3 12” strips and run it through a
tailed apprentice to flatten it then glue it back together.  But the thought
passed and I decided do it the Galoot way both for the experience and for the
satisfaction of the top still being a single piece.
> 
> The challenges are several (at least for me):
> 
> - I have never done any stock prep by hand (I have mostly stuck to joinery and
finish work with hand tools).  I know how to do it in theory, but have zero
experience.
> - I have to both flatten the faces and make them (more-or-less) parallel.  All
the “flatten your bench top” videos I watched don’t have to deal with this.
> - I need to remove a lot of wood.  The bow is about 1/2” so to flatten it I
have to remove a total of 1” (1/2 from the top face and 1/2 from the bottom).
In addition, it tapers by 1/2" from end to end, so that’s another big chunk I
have to remove from the whole width.
> 
> I have turned my crappy Stanley “Handyman” #4 into a scrub plane by grinding
the iron in an arc, https://groups.io/g/oldtools/photo/263744/3219531, and
started in (obviously just barely):
> 



-- 
Yorkshireman Galoot
in the most northerly county, farther north even than Yorkshire
IT #300