I've just finished my resin 28mm Vauban-style ravelin courtesy of Magister Militum. Despite soaking it in the bath in warm soapy water for several hours and giving it a good scrub the primer still didn't take until the above cleansing process had been repeated, this time with a liberal application of Cif (Jif to those of us of an older pre-EU generation!).
No worry really although I'm not sure I'm 100% happy with the end result. I have a couple of lengths of wall and a bastion to do so perhaps when they're all finished and on the table suitably populated with artillery and troops I will be happier. Exactly what I will use it for remains to be seen as I don't have anything to represent the glacis and suchlike. Perhaps it'll be best used in the 19thC where the absence of a glacis and outer works can be put down to neglect and budget cuts! It actually looks better with more modern artillery anyway.
The trouble is that this piece has distracted me from finishing off basing my Franco-Prussian French (well, some of them at least) and some Bavarians I picked up off eBay, although I did get the remaining French artillery done. Some progress too on the limbers and some more command bases.