Level 3 Skillchains

[FeralisCallidus]

I have never seen Impaction -> Liquification -> Fragmenation produce Light.

Neither have I, but I've done...

Shadow of Death > Sidewinder > Hexa Strike

Induration > Reverberation > Fusion [ Light ]

However there are no primary/secondary to a weaponskill.

Yes, there is. I'm sorry, but that's just plain fact.

[gix]

Very simple way to produce Light with Liquefaction -> Impaction -> Fragmentation in post65 XP PTs is Red Lotus Blade -> Raging Fists -> Dragon Kick, so yes it's very possible ^^
As for Impaction -> Liquefaction.... I don't think so, because you're not gonna get Fusion from that.