Note: This post was first published on May 17, 2016 at http://www.jyotibhargava.com
Since mosaics can be made with varying media and substrates, a careful thought on adhesives becomes necessary. Some quick considerations that come to mind are these:
. The intended location of the mosaic – outdoors or indoors
. Weight of tesserae – ceramic tiles, glass, shells or stones
. Size of mosaic – a large wall, a 3D installation or just a small coaster
. Climate conditions – overly humid or frost-ridden or dry
. Substrate material – cement, glass, stone, wood or metal
Here are the adhesive choices that I’m familiar with:
PVA
Fevicol is the most popular PVA used in India. The craft quality fevicol is 
graded as MR and it’s good enough for small wall art, but as the size of substrate and weight of tesserae go up, it’s prudent to use the carpenter quality PVA or Fevicol SH. Of late, I’ve seen Fevicol Marine being sold as a more waterproof variant but I still need to test it for outdoors.
Fevicol dries clear and it’s good for mdf, wood and fibre mesh.
Silicone
Internationally, silicone is recommended for mosaics meant for outdoors. My own experience shows me that the silicone we get here in different brands has less adhesion than Fevicol SH. I’ll keep checking more brands of silicone and post an update on the brand that works better than Fevicol SH.
For Glass on Glass, artists recommend thinly and evenly applied silicone as it dries clear. Those of you with experience with silicone should please share the silicone brands you’ve found effective.
Thinset
If not Silicone, the adhesive highly recommended for outdoors is Thinset. It’s essentially grey or white cement with chemicals for better bonding. Thinset is mixed with water, allowed a few minutes of slaking time and buttered on the reverse of tiles to stick to substrates like wood, metal, stones or walls. If a mosaic is created on fibre mesh, the mosaicked mesh can be applied to its intended substrate using Thinset. White or grey colour can be chosen based on the colour of tiles and substrate.
Popular brands of Thinset used by folks I’ve connected with are Laticrete, Asian Paints, Ardex Endura and Roff.
Epoxy Adhesives
Epoxy adhesives come in the combination of Resin and Hardener as in the popular brand Araldite. Once mixed, the adhesive has to be applied quickly as it hardens within minutes. Epoxy adhesives are waterproof and bond strongly but because they don’t dry clear and they give little time for applying to tiles, they aren’t favoured by many.
Pre-mixed Adhesive Pastes
I’ve known of white pastes from Kerakoll and Roff that are recommended for adhering fibre mesh or direct tiles to walls but because they come in large buckets, I haven’t acquired them for testing as yet. Those of you with experience with these adhesives are requested to share your views on the brands you’ve found effective.
Superglue/Quikfix
I use these adhesives for those odd tesserae that weren’t stuck properly and come off the substrate as I start grouting the mosaic. Their instant adhesive and drying qualities are helpful in those situations.
I’m sure I’ve missed many glues from the list above. In international groups, I keep hearing of liquid nails or elmer’s glue and the hugely popular Weldbond, none of which I’ve had access to. So do tell if I should include any more adhesives in my mosaic kit.
