Crikey Doug.
Be careful,mate!. [Linked Image]
Sounds like you might be in need of a regulator with a decent handle on it for a start.
Also I'd be replacing the gauge as well, they don't tend to work as well, after they've been over-pressured.
Compressed air has safety rules all it's own, it's sure dangerous stuff if it gets out of hand!. [Linked Image]