I am ashamed to ask this question - how to re-inflate fenders?

Stick a car 12v inflator onto the valve. You do not need an adaptor but just hold the fitting tight onto the valve so that it "smothers" it. This should get the extra air into the fender. It is fiddly to get the right fit over the valve but at least you are not expending much effort; once you get it right you can tell. The only difficulty is if your valves are sticky but short of removing and replacing them this route is as good as any.
Think this is the Majoni recommended route and it certainly worked to inflate my new ones last season.
Good luck
 
We asked the local chandlery, and they were happy to oblige, using a compressor and they had the right adapters. We have asked the one at Hamble point, and Arthurs in Gosport do it, and force four swanwick. I guess is most will have a compressor as they store them flat and inflate them at the checkout.
 
I really should be ashamed of myself, I know, but what sort of pump and connection is needed to get some air back into ordinary inflatable fenders? I knew this once but have forgotten!

Don't be. It never even occurred to me you could.
 
How do you do the ones without a brass air valve? Ours have a screw in plug and there must be a better way than what we've been doing.

Those sound like Polyform fenders. Compass Marine have special adapters for them. You unscrew the plug and just press the wide flat end of the adapter against the valve inside.
 
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