Help, fire box leaks

[meltyface]

I have a char grll with offset fire box and just installed a bbq guru. I noticed this weekend that the guru was overshooting the temp by a lot, and im pretty sure it is because the firebox leaks air around the tray and the door. Does anyone know how I can make thes a little more airtight, there are gaps due to it warping from use and heat, plus with it just being metal to metal it wont have a good seal anyway

 

[eman]

Either a high temp rope gasket or if the gaps are not to big high temp silicone used to fill the gaps.

You must clean the surface that you will apply the gasket to and then if you are using silicone apply a thick bead and cover w/ plastic wrap. . close the door so that it compresses the silicone and let dry. open door and remove plastic wrap.  If the gaps are in spots thgat don't move just fill w/ silicone. If using rope gasket apply silicone stick on rope gasket then close door let set .

 

[meltyface]

I was thinking about the rope gasket, but will that stuff catch on fire or otherwise be destroyed by fire directly contacting it?  Also, will the high temp RTV silicone be destroyed due to the same circumstances?

 

[sqwib]

I used the rope and RTV on my firebox, so far its holding, and this is the type of abuse it gets.