sealer

Anyone used zinsser gardz as a sealer prior to skim? Just wondered. It's brilliant as a sealer over 100 year old chalky surfaces and would work great on contract emulsion to prime. Not sure if it's good to skim over through?

Been looking about for some sealer and found this wickes stuff. Been trying it out as I wanted something that seals better than Pva but doesn't have the sand like blue grit. Found this from wickes but early days. Anyone used? It's also says to use this product before there one coat plaster and...

Looks to me it's disconnected? Everywhere around me has no stock. Ie trade centre and B&Q. Anyone hear anything about this? Guess I'll have to switch to some decent Pva instead when I'm doing repairs but no idea what to use if I artex a ceiling. Water based undercoat I guess,as that should work...