I cut a fair amount of Garolite G-7, G-11, & G-3 bonded fiberglass board. I find the best method is carbide & flood coolant. However, my coolant goes sour after a couple of weeks. I use or have used the Rustlick products Powerchip 2000 & WS 5050. I treat with Triadine 20 to retard bacteria growth & use Zebra odor control tablets but nothing works. Most of my work is in Aluminum so I need to stay with an all-purpose coolant. I only have 1 CNC so i can't designate a machine to a specific function.

Does anyone out there have a solution or use a different coolant?

Any help would be appreciated.