I myself thought about getting a S/H tank and having it expanded to 22 litres so I made inquiries with 'Hartlepool Radiators' who replied... "We carry out the expansion process and our RENU process at the same time so they're lined with a rubberized lining too. It takes approx. 4-5 weeks and the cost will be £450-480+VAT." Too rich for me I'm afraid.
