any way of freeing the buggers up? Have been given a nice set of road wheels but a whole bunch of the nipples are seized. Have tried WD40 penetrating oil (not the niormal stuff) but it seems to have had no effect

Probably not – what you are experiencing is galvanic corrosion.

Stainless Steel spokes and Aluminium nipples will weld themselves together under the right circumstances, and often the only way of getting them apart is destructive.

From an article about GC:

Aluminum reacts negatively to stainless steel… Severe corrosion is likely to take place in a marine environment.

So salt water, of which road wheels see a fair amount, causes GC.

For future reference, I’ve built a set of wheels using Sapim alloy nipples on stainless spokes. Used a smear of copper grease on all spoke threads as I built (a habit I got into years ago).

1000km in and had cause to tighten some spokes, they all turned nice and smoothly so hopefully a good sign for future maintenance…

ah galvanic corrosion, a sacrificial anode, lower on the reactivity list than the spoke material. Rest in Pieces alu nipples

ermm so is it worth buying 10 or so spokes at £10 to rescue some Fulcrum Racing Zero’s? probably yes…

Defo worth rescuing, are they standard spokes and nipples?

The spokes should be ok, it’ll be the nipples that have corroded. They will probably break or snap if a decent amount of force is applied.

If so, then replace the nipples with brass ones, and Bob’s yer dad’s brother.

It is difficult to give a conclusive opinion without seeing them though. If you know a wheel builder then get them to take a look and they should be able to say whether they’re salvageable or not.

no they are posh bladed spokes with big 6mm nipples (ooh errr missus). The spokes twist and snap first (then it’s a f@@ker to get the ends out of the ust rim! I’d probably cut them off if I decide to rescue them

Ah, different kettle of fish then.
I’m guessing the nipples screw into the rim, and then you screw the spokes into the nipples?
Out of my knowledge sphere as far as building though, I’m an old school J bend spokes and brass nipples man 😆

Racing Zeros are annoying to replace nipples, they have an undrilled rim bed, so you thread a steel insert in to the nipple, drop it in the valve hole and use a magnet to pull it out the spoke hole.