Rectangular cast-in-place liner for old chimney?

[Forthup]

We have a square chimney for a wood burning fireplace which no longer meets code. We want to keep the fireplace. It needs a new liner which will allow 0" clearance to combustibles (i.e. wood surrounding it), and which will not cut down the flue area too much.

I've been investigating cast-in-place liners. The names I've seen are Supaflu, Golden Flue, Guardian, and HeatShield with CeCure Shield. The web pages for Supaflu are "not safe", and there is no web site I can find for Golden Flue. Images I've found for both show a round liner. The Guardian system also apparently uses a round liner. A round tube will cut down the cross section too much to allow use of the open fireplace.

However, the HeatShield/CeCure system apparently can be done in a rectangular shape. Example here:
https://www.georgethechimneyguy.com/heatshield-system/sleeve-relining-system-cecure/

Info on the HeatShield/CeCure system:
https://saversystems.com/products/heatshield-cerfractory-flue-sealant

HeatShield’s hybrid “Cerfractory” technology combines the strength of a high-fired ceramic with the heat resistance of high temperature refractory cements. HeatShield Cerfractory Flue Sealant when used with CeCure Sleeve is certified to UL 1777- Standard for Chimney Liners by Intertek. HeatShield has been tested to ASTM C199 Standard Pier Test for Refractory Mortars and is rated “Super-Duty”. It exceeds both IRC and NFPA code requirements, which specify medium-duty.

It can be used to reline masonry chimneys with the addition of the CeCure Sleeve, provided the HeatShield Cerfractory Flue Sealant mix plus the CeCure Sleeve achieve a total minimum of ½ inch lining material thickness.

Does anyone have experience with these?
Any suggestions on finding an installer in west Michigan (the Mitten)?

Note that the fireplace is not primarily for heat, although we have a Grate Heater. It's in a mostly unheated 1901 summer cottage.
If we can figure this out there are probably a few dozen other cottages in the area which need the same solution.

Thanks.

 

[begreen]

Has a fireplace insert woodstove connected to an insulated 6" liner been considered?

 

[Forthup]

Yes, but not what we want. We want the fireplace primarily for aesthetic reasons.

We have also been told that a woodstove would put out too much heat for our purposes.

It's a bit like cooking on a charcoal grill. You could get pretty much the same results from a propane grill, with less mess to clean up. But people still like to cook with charcoal. Or having a wood fire at a campsite when you could cook on a bottled gas or white gas stove.