I have an oil-fired boiler for heating my home. This one is welded steel. There is a large flange (about 9" in diameter & secured by 6 bolts) where the controls & immersion coil go into the water jacket. It is currently sealed by the original gasket which is now leaking a bit. I bought the standard red 1/4" thick gasket matetial with plans to cut out a new one & replace it, but I have to wonder if there isn't a better, cheaper way.
Can I simply seal this flange with high-temperature RTV (also known as Silicone Rubber). The Black stuff is rated for about 600 degrees. Any thoughts?
Mike N.