[OldDeckHand]

'I wonder what is used to extinguish a titanium fire? I think it’s hard to put out."

The "dry powder" kinds of extinguishers. Class "D", I think.

When I was in college, I worked in the summer at a shop that did a lot of titanium work, with plenty of shavings. They had those Class D extinguishers everywhere.

[Jack Hydrazine]

Those class D extinguishers probably had graphite-based powders in them.