@ Nicholas
I haven't made accurate measurements but for example to do a complete VIC 20 or A1200 case I do the following...
PS:Before doing anything I give everything a good clean first with the ScrewFIX UPVC Cleaner to remove all surface dust, oily fingerprint etc...
50ml of Creme Peroxide
Half a teaspoon of Vanish Oxi Powder
Mix thoroughly and leave to stand for 5 mins
after 5 Mins it should have frothed up a wee bit
Another quick & thorough mix
Then apply with a paintbrush
Then sit under the UV light for preferably 10 hours, no point in leaving it any longer than that as by this time the chemical reaction seems to have dissipated and for heavily yellowed items another fresh coating and 10 hour soak should do the trick...
Managed to get meself a job lot of 15 UV lights on eBay for 16 quid (£5 less than I paid for the single bulb I bought at first) now Scotlands got it's own permanent source of UV light, getting a nice tan from it...
Still find it amazing how well this stuff works and I reckon you'll be pretty amazed too when you see the results for yourself...
PS:Gloves are for cissies be a man and use bare hands like I do, just remember not to pick your nose or rub your eyes till you've washed them though...