Don't use the terms "junk" or "shot" or similar emotion laced words. Instead of saying "worn out" say "worn beyond manufacturer's limits". Being worn out is subjective - the owner may argue with you - but worn beyond manufacturer's limits is factual - either it is or it isn't.
I've been known to use the word "artifact" to describe a "possible defect".
example:
My shop rejected a $200.00 sodium cooled exhaust valve as being "worn". The owner took the valve to another mechanic who said "it doesn't look worn to me" (like this guy had micrometer eyes!). The owner came back to us real mad and didn't want to pay for the replacement valve that we had put in his engine. If we had put "stem diameter worn beyond manufacture limits: .0502 - manufacturer service limit .0505 then we could argue facts. In fact, the other mechanic would know what the wear limit was and check it for himself, and probably would have agreed with us.
Engineering Reports:
Be careful when talking to engineers. Use measurements with caution. For example, if you say a part is out of round by .003 of an inch. The engineer might argue with you that it is not .003 but .002 inch. Either way it is distorted or oval or out of round.
So what words do engineers use to describe their mistakes? A service bulletin from an aerospace manufacturer describes a mistake in manufacturing as a "quality escape" Such words reek of lawyers looking over the shoulder of the engineer.
Email:
Consider all email as being public and lasting forever. Email sent to companies will be retained and will be asked for and produced during legal actions. Forget privacy. Sensitive topics are better discussed over the phone. However, email is good for protecting yourself and creating a record of a problem.
