Heat treat furnace

[Highpower]

(12-05-2015, 09:03 AM)RobWilson. Wrote: PS you probably know this but others may not , stick a few bits of charcoal in the furnace with your part , it uses up the oxygen in the furnace chamber as it burns  and so cutting down on the scale/oxide   on parts ,its not a perfect solution but it is an improvement. Keep the door shut as much as possible .

Rob,

Is there a 'rule of thumb' for deciding how much charcoal you add in with your part?
"A few bits" leaves it open to a pretty wide range of interpretation.....

I've seen it suggested a few times to add a piece of char cloth in with a part if you are wrapping it in stainless 'foil', but again I'm not clear on how much is 'just enough'.

Fortunately I was a boy scout, so at least I know what 'char cloth' is......