Hello-
I've got an original 1990 automatic halon system in the engine compartment. Although the indicator light shows good, I doubt it's ever been serviced, and, of course, is now obsolete.
Question is, what's the better chemical alternative? Novec or HFC-227 system? Or other compound? Thanks.

HFC-227ea or FM-200 (same thing) was essentially the first of the Halon replacements and is made by Dupont. The difference with FM-200 (and also Novec 1230 or Sapphire) is that they are considered clean agents, whereas Halon was not. FM-200/HFC-227 is actually a refrigerant and suppresses a fire in 2 ways...it cools the fire and breaks down the chemical reaction. Novec works very similar also. Both are good at suppressing the fire, and honestly, I'd buy whichever is cheaper (most likely FM-200) Novec is made by 3M under the brand name Sapphire.

Novec has been marketed as the "cleaner" less ozone depleting agent, but there's really little different in the environmental issues with either FM or Novec.

On another note, if your Halon is still showing proper pressure, it's probably still fine. My boat is also a 1990, and had the original Halon still. I had a fire in 2015, and it worked perfectly. You may also be able to pull the tank out and weigh it, as the proper weight might be stamped on the tank.

Thanks for the tip. Doesn't halon have a tendency to settle over time? I remember something like a drop/shake test to see if it has conglomerated. I'll have to remove it regardless. I guess trusting a safety device that's sat idle for 28 years just kind of makes me wonder.

No, those are dry chemical ABC types.

Halon Frequently Asked Questions

Do you happen to be in the fire suppression business?