Tank Drain Pipe Locations Template

We cut a piece of 3/16 luan exactly the size of the top of the new tank.  We used this as a template to locate and mark the 3 holes we needed to drill for the 3 drains that dump into the tank.  To make the template as accurate as possible we marked it with the center of the large drain on the back of the tank as well as the threaded rods and support brackets/straps that will hold the new tank up and in place.  We put masking tape in the areas where the 3 drain pipes would meet the new tank.  We also measured, cut and put in place each of the small pieces of drain pipe that would connect the plumbing coming down from the coach and go into each of the tank grommets.  These had to be exactly measured and cut so they were the correct length to properly seat in the tank grommets once the tank was put in place.  We did not do this for the toilet drain yet as we could later mark that position from inside the coach.  We then coated the 2 and 2 1/2 inch drain pipe ends that were in place with dirty engine oil.  The template was carefully and accurately raised on a 2 foot square of OSB on a floor jack up against the two drain pipes.  Each pipe left a ring on the template marking where the holes needed to be drilled in the new tank.