I recently installed a fermentap weldless ball valve kit and a weldless thermometer on my 10 gallon stainless steel brew kettle. Following the directions, I found both the ball valve and thermometer leaked. After reading some posts on here, I placed the supplied red washer (which I presume is silicone) on the inside and a rubber washer on the outside. The HBT thread did not say to use a rubber washer, but that's all I had here at the house. I have tested it and they no longer leak, but I haven't tried it out during a boil. I'm wondering if the regular rubber washer on the outside will melt. Any thoughts? Should I try to use a silicone washer? Thanks.