I've just tried the Liquid Quartz Sealer and had excellent results as per waterproofing, however, on other items (partially glazed and twice fired to cone 6), it's showing a mould like surface discolouration after putting it through a dishwasher several times. I'm starting to think this is because I sanded the raw parts of the item and didn't wash and dry thoroughly enough before spraying on the LQ. So moisture is possibly trapped creating the awful grey mould appearance. I've decided to refire to remove the product and burn of the mould.
Hopefully this will eliminate the problem and I will be wiser next time.
