7" 24 gauge slip joint

Guys,
We have a stove installed in a caboose and the pipe comes off the top of the stove and straight into the ceiling. It needs to be changed and to do that we can knock down the old pipe but getting the new pipe installed we would have to unbolt the stove from the floor and tilt it back. Would a slip joint section of stove pipe work to "fill in" the space from just below the ceiling into the chimney itself? If so, how does slip joint pipe work?

I have a slip-joint connector between my boiler and a DuraTech ss chimney. It's just a slightly smaller section of black pipe that slides up into the black pipe connector on the chimney. It sounds to me like that would work great for what you describe. Be sure to screw the two joints together with at least 3 sheet metal screws.

Depending on the length you need, you may have to add additional pipe sections, since the telescoping lengths come only in 4' and 5.5' (fully extended) sections. A telescoping length should work well for you. You can see pictures of typical installations at http://www.mtlfab.com/metalfab/content/view/full/385 just click on the "Typical Installations" tab on the right side of the page.