coalminecanary

I've got soft fire brick, I plan on stacking and sealing all joints and seams with fire place mortar that's good up to 2000F, once that's all done I plan on dressing and smoothing the inside as needed then coating the inside with ITC 100, all surfaces to be dampened prior to product application, I've got rigidizer and for that or if it's better I can use water. I know the mortar I've got is only good to 2000F but I figured with the coating of ITC 100 inside it will offer pretty solid protection, any critical flaws anyone can see with my method? Cheers!