Originally Posted by muddywater
Well if right is right and wrong is wrong then your rule of thumb is wrong. If i ever install irrigation with a poc at the bottom of a mountain, i will just google it like you did.
Rule of thumb is a Jim Crow law pertaining to the size of stick you could beat your wife with; as it could be no thicker than your thumb. Therefore by saying "rule of thumb" he means a rough measurement that is quick....
.... holy crap, that was the first time I actually used my expensive degree.
In the real world of installing there are a lot of "rule of thumb" measurements made. If you would like to walk onto a commercial job site and stop everything to get scientific more power to you, but you'll go broke quick. Making quick judgement calls based on experience and knowledge you can recall quickly is what separates the Men from the Boys. Having a solid "rule of thumb" list invaluable.