BIS 1.2 Rebuild Help

[northernguy]

I have a early model bis 1.2 that I'm in the process of restoring. The grate was corroded and the back refractory had a bad crack and the upper baffle has a sag and slight cracking. I went ahead and pulled everything out today. The back panel basically cracked in half taking it out. The sides look ok, some slight chipping on the top edge of one.

Now that the metal liner is exposed I can see slight warping in the back and right side, bows out in two spots on the back a bit and one bow on the right.
The back of the liner also has some rust. I've attached pictures but it's near impossible to see the bowing, it's almost like a wave across the back, but barely a 1/4" difference.

Is the warping or slight rust anything to be concerned with? If I replace the back refractory and the baffle should I be good?

I'm getting a chimney sweep end of next month where they can give me a better idea, just wondering if I should hold off until them before buying the replacement pieces.

 

[northernguy]

To summarize, my main question/concern is around the slight warping and surface rust in the back of the firebox.
Is this something I need to concerned about or should it be ok to just put in new refractory & baffle? There are no holes or cracks.

My gut tells me as long as the new panels go in properly then I should be fine, but I haven't seen many of these without the refractory panels so I'm not sure what is normal vs what could be a problem.

Another thought, is there any high temp rust paint or something I could use to slow the rust before reassembly? Or just leave it?

 

[begreen]

The warping seems slight, it's the rust you want to check out. If this is just superficial then it may be ok. If it is rusting more on the outside then the metal may be thin there. Take a screwdriver and poke a little at these areas to see if they are solid.

 

[northernguy]

The warping seems slight, it's the rust you want to check out. If this is just superficial then it may be ok. If it is rusting more on the outside then the metal may be thin there. Take a screwdriver and poke a little at these areas to see if they are solid.

I think it’s superficial, could probably just sand it off. Can’t see the other side, it’s double walled with a several inch gap between. Pushing with a screwdriver just makes the wall flex a bit, seems solid enough.