DerbyDad03 wrote:
On Monday, April 11, 2016 at 7:06:55 AM UTC-4, dadiOH wrote:
DerbyDad03 wrote:
On Sunday, April 10, 2016 at 7:17:01 PM UTC-4, dadiOH wrote:
DerbyDad03 wrote:

Groove or on top of a batten? How is it attached to the sides?
In either case, how much do the sides extend below the bottom?

Grooves in the sides and front. The groves extend about 1/2" below
the bottom panel. The bottom panel is now kind of bowl shaped,
sagging
left
to right as well as front to back.

Simplest fix is 3 screws through the bottom into the back. Put one
in the center first, then one more on each side halfway between
center and side. That should fix the sag in both directions; if
not, slack off the last two, add another one (two more total)
between
them and center, then tighten the loosened one.

Ah, if it were only that simple. To repeat what I just posted in
response to dpb's post...

I clamped the bottom of the drawers to the back of box in three
spots, completely closing the gap along the back. The front and
sides of the bottoms are fully seated in the grooves of the box. I
placed a 36" straight edge across the bottom of the interior of the
drawers and measured the gap between the straight edge and the
bottom of the
drawer
at the center of the bottom.

3/8" on one drawer, 1/2" on the other.

And what happens if you push up on the bottom while it is clamped?
Sag disappear? If so, then either the bottom isn't fully seated in
the grooves or the grooves are too big. If not, try loosening the
clamps THEN pushing.

OK, when I say fully seated in the grooves, I mean that as much wood
as can be seated with a *bowed* bottom is in the grooves.

Of course if the bottom is bowed the wood has to pull out of the
grooves and can no longer be fully, 100%, in the grooves.

Bottom line is that the bottom is bowed into a shallow bowl shape and
simply securely the bottom to the back of the box is not going to
eliminate the sag in the middle of the bottom. There is no way that
your "simplest fix" of 3 screws across the bottom into the back is
going to flatten the 1/2"
sag in the center of the bottom. Yes, it will flatten the *back* of
the bottom but not the center of the bottom.

Which means that you have to get the bottom fully into the grooves. Or, at
least, far enough to remove the "belly". Once there, a couple of screws
through the bottom into the sides should take care of it.

The question is, why did it bow in the first place? I can only think of two
reasons...

1. The grooves are wider than the bottom is thick. If that is the case,
pushing the bottom flat and gluing in a few small wedges into the too wide
groove should fix it.

2. If the grooves are not wider than the bottom is thick then the drawer
sides have moved out of vertical and possibly parallel. Is the distance
between the sides exactly the same at both top and bottom all along their
length?