Purple colour on blade

[WolfGang]

So i had a green branch of a pohutukawa (http://en.wikipedia.org/wiki/Metrosideros_excelsa) which i decided to saw into smaller round for general use, this was fine until i took my Clipper (carbon) to remove the bark and a coating of purple was left on the blade only, not the wood and it hadn't happened to my saw either.

i had sharpened it the other day so it had a reasonable fresh coat of Camellia Oil on it which i guess reacted to something in the sap


anyone else had a similar experience?



on a side note not to worried about my blade it already has a good patina on it and now it has a somewhat purple colour on it now

 

[salad]

Carbon steel will stain a whole range of colours depending on what goes on it, you can clean it off if you like with things like stropping compound or you can just leave it on to form a patina which can help to offer some protection to the blade.
My main user has been stained so many times that the steel is a dark grey colour now, I don't bother cleaning it off

 

[robin wood]

chances are the tree has tanin in the wood which reacts with steel to give the stain. It's not a problem, cleans off easy enough with a bit of mild abrasive/stropping compound such as autosol.