how do i load a fire extinguisher full of paint?

Answer 1

Not recommended.

You'd want to use a pressurized water type unit since just about any liquid would work. Fill the unit about 2/3 full and then close the valve. Top it off with pressurized air, you should be able to do that through the fill port (it's the same type of valve on a tire.)

Don't do anything stupid with it.

Answer 2

Most small red fire extinguishers are non serviceable. That means they are designed to be used until expiration date then discarded. They cannot be recharged because they cannot be taken apart. A larger, more expensive unit can be serviced/recharged and I expect you could take the head/valve off, remembering that it is under pressure, dump out the powder and refill it with paint. But then how would you recharge it with nitrogen? Nitrogen is the propellant than moves the powder, or in your case paint, and it requires a special recharging kit that is not available in most toy boxes. . Otherwise you would simply have a can of paint. And not a spray can either.

Answer 3

Depends on the type.

If you want a real mess..not particularly paint, I'd suggest a powder type extinguisher. You can unscrew those and ad pigment to that white powder. Any art store sells that. Color suggestion would be ultramarine blue, crimson red. Do NOT replace with the pigment, just ad about half a cup or replace half a cup.

Good luck.

Oh BTW: The police doesn't think it to be that funny and the fine is substantial.