I have a few questions about machining magnesium and would appreciate any advice I can get.
I normally machine aluminum...6061 and A356, using a trico md1200 micro drop coolant unit with their veggie oil....works great, nice surface finish, no complaints.
I have a project where weight is critical and I want to use mag but have heard horror stories of machines catching on fire, etc. when mag isn't handled carefully.
I don't want to flood cool if I don't have to, but don't want to burn my shop down either!!!!!
Anyone been here and made it work?
Thanks in advance for any help!!

You have to have three elements to make fire. Fuel, Heat, Oxygen. The normal machining process is not enough heat. The material will give of Hydrogen at a faster rate as Aluminum while in coolant. I have machined and been around the machining of Mag. The only incedent we had was when an operator left a clamp up that got into the spindle. The metal to metal contact made sparks the ignited dry Mag. By using a shovel to remove the burning material it didn't get too bad. The operator ran very far away though.

we do a bit of magnesium turning/milling. as long as you have coolant on the tools/workpiece, you should be fine. but if you don't there is a very good chance you'll torch your machine.
we were turning magnesium parts in a cnc lathe years ago. the previous operator cleaned out the machine, and forgot to turn the coolant for the machine back on. the next shift came in and started running. didn't take much time for the machine to become a flaming grill. needless to say, that machine was scrapped.
if you're careful, you should be fine though.