Overview of Adhesives for Mosaics
In my free book, "2022 Mosaic Handbook" I have a section in there about adhesives. I thought I'd add it here in my blog for those of you who don't have this handbook.
There are a myriad of adhesives that are used in mosaics. Some glues work well on certain backers while other glues could be harmful to a particular backer. Everyone has favorites and there are differing opinions on what works. So, here is a general overview for you, and I recommend if you aren’t sure, experiment on a small piece before you use it on your project.
White Craft Glue (I use Weld bond), is great for indoor projects. You can use it for gluing glass, vitreous tiles, and many more materials. It is also used in sealing porous backers, just mix 1/2 water and 1/2 weld bond and brush over backer, like a terracotta pot. It dries clear, is easy to work with and clean up.
Weld Bond can be used on acrylics, glass, mesh, Hardie backers, MDF, wood, stones, Skeewbackers, Wedi board, styrofoam, terracotta, and more. Weld bond comes in plastic bottles that are easy to work with. You can just squeeze some onto the back of your tile and then press the tile down to the backer. Or you can spread some weld bond onto an area of your backer using a Kraft stick or something similar, then lay your tiles into the glue. Be sure not to use so much that it oozes up and fills in where you need grout to go. Clean out any excess glue with a sharp tool.
Thin set (mortar) is what I use for almost all of my outdoor projects or for mosaics exposed to wet areas. You can use thin set on just about any tile, glass, found objects, smalti, marble, dishes, etc. It is a little more challenging to work with as you need to control the amount you use so it doesn't interfere with your grout lines. It comes in powder or pre-mixed. You can add colorant to it and use it for both your adhesive and your grout. Be sure not to use so much that it oozes up and fills in where you need grout to go. Thin set can be used on plywood, mesh, brick, cement, concrete, Hardie backer, MDF, wood, Kerdi board, Wedi board, Skeewbackers, stucco, styrofoam, terracotta, textiles, to name a few.
Epoxies - For metal surfaces, neutral cure and water-resistant silicone, epoxies, PL500 construction glue can be used. Some epoxy is a 2-part adhesive and has strong fumes, so work in a ventilated area or wear a mask. Do not use any cement-based adhesives like thin set with metals as any rust from the metal may break down thin set and grout.
Clear Silicone Adhesives - These works well for glass on glass. It is clear and waterproof.
Mirror Adhesive - Mirror adds great shine and reflectivity to mosaics and is fun to have in your art. You should use a glue specifically made for mirror to glue it down. Make sure it states it is for mirrors. Do not use white craft glue or thin set, as in time it will eat away the silver backing leaving a black spot. I learned this lesson the hard way.
E6000 - This is a glue used a ot in jewelry making. It can work in mosaics as well, only never, ever use it around any kind of foam core boards or styrofoam, as it can melt it. So do not use it with Skeewbackers, Wedi board or Kerdi boards which have foam core centers. There are some fumes from it, so work in a ventilated area or wear a mask.
MacGlue - I’ve never used it but lots of mosaic artists love it. It is a white glue that works similar to weld bond - it dries quick, and bonds on glass, wood, tile, concrete, plastic, terracotta, and more. A lot of mosaic artists prefer it for Glass on Glass (GOG) work.
Be sure to read the labels and know that it will adhere your materials and not damage any of them. Engineered backers frequently have a polymer core that will be damaged by a variety of ethyl compounds. Acrylics may be made cloudy with solvent-based adhesives. So research and experiment.
There are lots more in the market - try them for yourself and you’ll figure out what works best for you.