I put masking tape on new upvc windows to protect them as the house as just been rendered and I can't get the damned stuff off. It never peeled off in one go , just bits of it. Have tried hot soapy water... not helped a bit. Nail polish remover, no effect. Petrol works but very slowly and I'm sure it is softening the upvc as well. It has took me and the wife approx 2 hours to do one window sill. I have the stuff all over six windows and door frame. Is there a product I could buy or some magical formulae. Also tried a new stanley blade, that dosn't work.
Any advice appreciated.