[k2]

We need to build an 18in x 80in x 24in pantry cabinet. The plan is to buy a 24 in pantry cabinet for the sides/back/shelf and use a sacrificial 18in base cabinet for the top and bottom. That way we don't have to try to redrill the corner bolt holes in the pantry cabinet.

But - the only 18w x 24deep cabinets appear to be the base cabinets, and the top of the base cabinet is open. Am I missing an 18in wide cabinet that I could use? If not, how have people finished off the top of the pantry cabinet when they have used the 18in base cabinet? I suppose we could cut out the missing piece from the top of the 24in pantry cabinet. Are there other solutions?

Fortunately that top will be hidden in the pantry - and way up high - so it will only be visible from the inside of the cabinet.

[splatgirl]

So it sounds like from a visual perspective at least, that it doesn't really matter if the top of the cabinet is open? (Do you have the door situation addressed?)
I see two options:
let it ride with the slat top that is standard on the base cabinets--maybe use a few corner braces or something to sturdy it up a bit, but if it doesn't matter cosmetically, it doesn't really matter...
or
Cut down the top from the sacrificial cabinet to 18" if you want a solid top. I would probably go this route since you'll have it on hand anyway.

[mrprez]

You can use an 18" shelf. You get 2 of them for $10.

IKEA | Interior organizers | Storage organizers | RATIONELL | Shelf

[k2]

Thanks! It sounds like inserting a piece from the cabinet top or a shelf will be the answer. Any other ideas?

I think we have the doors/drawers figured out - more or less. From the bottom - 2 drawers 15in high (18wx15h doors used as drawer fronts), a 6in drawer, a 24in door used as front for pullouts, and a 18x18 door on top. It looks like we're about an inch short (my calc is 7/8"). We'll use some trim at the top to fill any gap there - unless we've run into some place that needs a filler some place else.

Does this sound like it should work?

(Bottom drawers will be for recycling bins. I discovered that our (old style) Ikea gray storage/garbage/recycling bins should fit in the 15in high drawers. Yeah IKEA! Our town has not discovered comingled recycling, so we're still tossing the stuff through 20 different holes in a long wall on cold winter mornings...)