152 Fuel Watcher Save FUEL FOR BATTLE! Strips of felt etc. tied with wire or string Wrap all pipes Strips of felt or old carpet Old blankets or quilts Corrugated cardboard or paper A typical hot-water system show- ing tank and pipes bound round with strips of suitable materials. Lag pipes ... You may think "lagging" is a long and complicated job, but it is really very simple. It does not matter if you have none of the materials shown in the above diagram. Anything which has been used for keeping heat in the body will also serve to keep heat in your tank and pipes.