03-01-2011, 01:54 PM
he biggest problem I see with silicone is that it tends to leave a thin insulating coat on everything it touches, and it may be difficult to get it off of the tops of the rails on either side of the gaps. It stays soft and rubbery, so it may push out of the joint and allow the gap to close if the rail expands. It could also then create derailments if it pushes out of the gap due to rail expansion.