Why use thread compound? Lubricating machine screws with compounds like Permatex or Loctite decreases friction in the threads, allowing for truer torque measurement. It lessens the likelihood of binding during the torque phase which leads to over-torque and mashed threads. Some compounds function similar to lock washers, preventing the proverbial screw loose. Thread dopes also inhibit corrosion and seizing. For marine applications, avoid using the automotive Never-seize. This gray goop contains lead, and while it works great on land applications, it can actually increase electrolytic corrosion in marine applications. Remember, there is little in life more frustrating than seized parts. So save on labor and take a moment to dash on some thread treatment. Instead of busting knuckles over frozen bolts, laugh as someone else down the dock launches wrenches out to sea.
Permatex and Bondo produce gasket makers and sealants designed to hold tight in whatever application you need. Blue, Red or Black RTV goop, high temperature and oil resistant sealants will keep engine oil in its place and coolant happily circulating where it belongs. Save time by preparing the surface meticulously first, or spray on some Permatex Gasket Remover for an extra hand. Quality compounds engineered to withstand temperature fluctuation, vibration, and engine fluids will keep that marine engine logging miles and not repairs.