lead loading v's body filler

Need to fill some holes and an old series 1 landy bulkhead after it came back from shotblasting. They're pretty small, I'd say 2-3mm. The shotblaster recommended filling with lead. Does it do a better job than normal filler? I've found a lead loading kit but it's about £60, and I've a tin of Isopon under the bench in the garage.

lead is thecnically better, but there is a knack to doing it.other thing is rust will nevercome through lead…..but it can come round it. It only really exists as before plastic isopon type filler was invented that was used for everything.
if you want a good repair you have to remove ALL rust! if you do this it doesnt matter what you put in as there is no rust left an as long as it is protected from the atmosphere you will never have a problem again.
in short lead isnt a wonder fix, its an old school fix.

Chemical anti rust treatment followed by isopon. Just as effective.

Old skool is always best, regardless. Have you learned nothing on STW?

Lead loading is a 'dark art'. You must get the finish perfect because you should never file or sand it. Use a modern polyester body filler. Not the stuff that's been sat under the bench for 2 years though.
Hth
Marko