On 02/11/2020 09:04:14, Tim Lamb wrote:
In message , Andy Burns
writes
Fredxx wrote:

What's wrong with iron nails?

Ask the sawmill
Also discolours Oak. The last *blue Oak* stain I followed turned out to
be a fixing for a telephone cable run. Probably fitted around 60 years ago.

Yebbut - will the resident birds care over a little discolouration of
their 'house'?