Not sure which product to use?
Owatrol OilFrom £16.13
Colourless, penetrating rust inhibitor & oil-based paint additive
Water-based paint conditioner to eliminate brush and roller marks
VC175 Mould Killer£17.22
Stops mould growth - add to paint, mortar, grout or adhesives
E-B (Emulsa-Bond)From £30.90
Water-based mix-in bonding primer and first coat of paint in one