Gluing one tile at a time using Weldbond mosaic adhesive is more easily done if you increase the working time of the glue by preventing it from drying out.
NX Standard Wall & Floor Adhesive - White - Palace Chemicals
Adhesives for natural stone tiles
WHAT ADHESIVE IS RIGHT FOR YOUR MOSAIC PROJECT – The Mosaic Store
Ready-mix tile adhesive vs powdered tile adhesive
How to Use Tile Adhesive and Its Types- Roff
How to make mosaics: the tile adhesive method (or the thin set method)
Primers & Additives
MusselBound Makes a Strong Play for Accent Tile
TILE RESCUE Injection Repair Adhesive is a Professional Strength, fluid, non- expanding repair adhesive designed to re-bond and permanently save those
TILE RESCUE Injection Repair Adhesive 3 Pack of 10.5 oz. Tubes