Q: Jason, The opening immediately above my fireplace damper is large, but it tapers down to an 12" oval flue. The round flue is 40" from the top of the damper. Problem is that your extender is only 16" long. Can you put two of the extenders together, or make a custom long extender? -TJ
A: TJ, Working in your fireplace can be messy business. So dont forget those saftey glasses.
That said, there are "unofficial" ways to get a 16" extender to reach further. Keep in mind what I am about to share is not manufacturer approved modifications for your Chimney Balloon or extender.
Some people daisy chain two extenders together, and this is perfectly acceptable.
Other customers have been known to disassemble their extender and reassemble it with a longer PVC tube section (see image at left) since the extender tube section is the same ID as a standard 5/8" ID PVC pipe often used in electrical conduit. Sometimes these tricks work and sometimes they dont. The image here was sent to us from a customer, and it was about 4.5 feet long. It was difficult to get in the fireplace opening. If you do decide to modify your own extender dont make it more than 32" long. But again this is a non-approved modification. - Jason