The glue you choose will depend on the surface you wish to mosaic and whether your mosaic will be placed inside or outside. Below is a list of popular glues, along with tips and required prep work.
1. Thin Set Mortar
Thin Set Mortar is a cement based adhesive which is ideal for almost every outdoor application. The white variety, called Superflex, is available at the Vinery and is freeze and thaw resistant. We suggest using thin set mortar for mosaics on cement, any time your project will contain water, be submerged in water or be continually exposed to wet conditions.
Tips: Thin Set Mortar comes in a powdered form. Mix it with water until it is the consistency of thick mud (mixes up just like grout). Its working time is only 30 minutes, so be sure to mix up only a small batch at a time. Using a tooth edged trowel allows you to apply the correct thickness of mortar. Since Superflex Thin Set Mortar is white, you are able to use both opaque and transparent glass!
The Projects: Flower Pots, Bowling Balls, Bird Baths, Address/Patio Stones, Patio Tables, Shower Floors
The Substrates: Terracotta, Unprimed Plywood, Concrete, Cement Paver Stones, Cement Board, Unprimed Hardwood, Drywall
2. Ceramic Tile Adhesive
Ceramic Tile Adhesive is traditionally used to glue down ceramic tile floors and walls. It can be pried up later with a lot of effort (whereas Thin Set Mortar won't budge!). It can be used on articles that are occasionally splattered with water, and is tacky enough to be used on vertical surfaces too!
Tips: Ceramic Tile Adhesive is a grungy yellow, so make sure to use only opaque glass!
The Projects: Wall Panels (mirrors, picture frames), Indoor Tables, Backsplashes, Furniture (rough up existing finish)
The Substrates: Primed Particle Board, Primed Plywood, Primed Drywall, Floors (consider exposure to water), Unprimed Hardwood, Salvaged wood furniture
Weldbond glue, touted as the glue that will bond any surface together, can be used for a variety of applications. The best advantage of using Weldbond glue is that it dries clear, so it can be used in glass on glass mosaics. In our experience, Weldbond is not water proof, however, and must be used cautiously in applications where it may be exposed to water.
Tips: Weldbond can take a long time to dry on non-porous surfaces like glass, so brush on only a very thin layer of glue. Try choosing a textured glass as your substrate so that any bubbles in the glue will be concealed. On vertical surfaces, it helps to apply a thin coat of glue to the entire surface first and let it dry. Then, apply your pieces as usual. Otherwise your pieces may slip right off.
The Projects: Garden Stakes /Suncatchers(Seal with Armorcrete), Candleholders, Decorative Vases (dried flowers only!), Wall Hangings
The Substrates: Textured glass, Glasses votives, Glass vases, Primed Plywood/Hardwood
Disclaimer: No warranty is implied by these instructions. Please wear goggles when cutting mosaic materials or mixing grout. Mosaic materials are often sharp. Keep out of reach of children. Do not dispose of mosaic material in your household plumbing. Please link to these instructions freely, but email us if you would like to reproduce them.