This morning I have spoken to The Welding Institute in Cambridge, a
research and applications institute rather than a welding workshop. The
advice from their health and safety man with regard to fumes and milk was
as follows (wording as best as I can remember, but the point made is
exactly the same). "There is nothing to prove that milk is beneficial to
welders unless they ingest the hazardous materials. The biggest problem is
inhalation of welding fumes."
If anyone can produce properly researched evidence that milk is going to
help, I would always err on the side of caution. You only have one set of
lungs and one life. I have already compromised my lungs - do you want to
be a schmuck as well?
PS thanks to everyone who mailed off list in support - I have taken off and
hung up my flame proofs.