CEMENT BASED ADHESIVES
Tiling adhesive is available in most hardware stores and is relatively inexpensive. The bond to both the tesserae and the backer material is improved by adding a commercial tile bonding agent and priming the backer material with the same product, before applying the paste. Alternatively you can mix your own cement mortar, at one part cement to 3 parts sand – but best add a polymer waterproofing / bonding agent to improve the durability and adhesion of the paste. Cement based adhesives are suited for the indirect method of mosaics for making an adhesive bedding and are best for outdoors work and for floors and heavily trafficked areas.
PVA OR EVA GLUE
Polyvinyl Acetate (PVA) is water soluble, readily available household glue that can be used for non load bearing internal work, such as wall plaques. A waterproof variety is also available called EVA, but it is also not suited for external work. These glues are especially suited for the direct method of mosaics as the mosaic blocks or tiles can be individually buttered with the glue, prior to placing.
WALLPAPER PASTE OR WATER SOLUBLE CRAFT GLUE
Water soluble craft glue or wallpaper paste is used to adhere the mosaic tiles to the paper backing sheet for the indirect method.
EPOXY RESIN
There are a number of epoxy resins suitable for both internal and external mosaic work. These two part, very strong technical adhesives are somewhat tricky to deal with as they are extremely sticky, can be quite runny and usually set fairly fast. Not for the beginner to mosaics.
SILICONE
Clear Silicone is useful for working with glass mosaics as it lets through light, it also does not damage the silvering on mirror tiles, but some silicones are not suited for use against cement backing surfaces.
GROUTS
The grouts that we use for mosaics are usually cement based tiling grouts, inexpensive at any tiling or hardware store. A small bag of grout goes a long way. Additives are available to make them more waterproof, where this is important. They come in a variety of colours and can also be stained further to suit. Plain cement mortar may also be mixed up if preferred usually at the ratio of one cement to three sand – pure cement, used without sand, is not advised as it shrinks when setting. The best bet is to buy your grout ready made.
