Of course, I should have thought of that, Graham! Google is not exactly a friend, I approach it with caution in case it might bite or something. I am, as I may have mentioned before, a fossil in these matters *, but thanks anyway.
The recommended process involves up to 10 (TEN) stages! Worth it, though, when the velcro on my trusty sailing 'topcoat' declines to function. I will apply myself.
Michael
*Actually, I may have my new VHF radio (plus licence) to play with at Ullswater, so possibly I'm not a totally lost cause.