At the end of 2019 Mosaic Art Supply was e-mailed by a local homeowner about repairing a stone mosaic that was being displayed outdoors.
The design of the mosaic is a smaller-scale interpretation of the “Tree of Life” mosaic found in the bath of Hisham’s Palace in eastern Palestine. The palace dates to the 700s and today is considered one of the most important examples of Islamic architecture in Palestine. This particular mosaic was most likely made in the 1990’s.
Natalija Moss writes up the process she and Angela Bortone performed to restore the mosaic:
The mosaic measures approximately 4 feet by 4 feet. It was suffering from water damage. The backer was disintegrating, tiles were popping off, and the surface of the mosaic was beginning to warp and wrinkle. The steel frame around the mosaic was thoroughly rusted, with holes in some places. The edge of the mosaic was stained with rust in several places.
I felt like the mosaic was repairable, but I would need some help. I contacted local muralist Angela Bortone, who used to work at Mosaic Art Supply, and together we decided we would tackle the restoration.
Many artists like to choose background colors after the central figures have been tiled.
It is best to tile from the middle and work toward the edges to avoid awkward spacing between at key focal points, but you should not leave the color choices for the background as a complete afterthought.
Nor should you have firm color requirement for the background and tile the central figures without placing that color next to them just to see if they work.
Avoid “painting yourself into a corner” by doing a lot of cutting and mounting without thinking ahead.
“Thinking ahead” can be as simple as placing a single tile next to what you are tiling now to see if it has adequate contrast.
The following method is only recommended for dry indoor mosaics. Artist Megan Adams recently used it to save a mosaic that had been compromised by white grout, which makes tile colors look less intense and the mosaic as a whole “bleached out” in appearance.
We put white grout in bathrooms because it is used as an indicator of cleanliness. It’s use in mosaic art is limited to making your project look like a summer camp project. Avoid it. Consider black or dark gray grout instead to make your colors look intense.
Also keep in mind that traditional sanded grout is lighter in color when it hardens, and so sometimes a light gray or light brown grout can turn out looking like an off-white and cause the same problem as if you had used white grout.
Artist Jill Gatwood uses the following method to make water-resistant foam-core mosaic backers for exterior mosaics, such as the Pet Memorial Name Plaques she does for clients who need something that is lighter weight and easier to ship than stone or solid concrete. The method wraps the foam in three or four successive layers of fiberglass mesh and thinset mortar, and that coating is pretty tough, tougher than stone. (The combination of polymer-modified cement and fiberglass can withstand blows that would easily crack granite of the same thickness.) Continue reading →
Jill’s instructions have convinced me that there are enough mosaic applications for silicone adhesive that we should sell it. Note that we still recommend thinset mortar or Weldbond for mosaics on architectural surfaces such as backsplashes, but for projects such as mosaic mailboxes or glass-on-glass mosaics, silicone adhesive is preferred.
Jill’s steel mailbox instructions are fairly complete and include recommendations for purchasing the right type of mailbox for the project and modifying it as needed.
Steel Mailbox Instructions
1. Selecting The Mailbox
Jill says that a steel mailbox from the big box home improvement stores or a hardware store will work but you have to check it and make sure the metal is strong and doesn’t flex. (In practical terms, this means you should buy the mid-grade or premium model and not the one made for the bottom of the market.)
Jill recommends getting one that has ribs to strengthen the frame if you need an XL size mailbox. Continue reading →
I have often used a small screwdriver to pry up tiles when I wanted to change some detail in a mosaic, but in all of those cases, the mosaic had a grout gap, and it was possible to knock an individual tile out or shatter it without damaging its neighbors, at least most of the time.
But what if you can’t afford to damage surrounding tiles or you have a mosaic with no grout gap? Is it even possible to get tiles up? The answer is yes, and the method involves a wet cotton swab, a dental pick, and a sharpened chopstick.
Many people report having trouble cutting vitreous glass mosaic tile reliably because of the embossed patterns on the back sides, which can interfere with the blades of the mosaic glass cutter, but if you take simple steps to minimize interference and rotation, it can be done.
What I mean by interference is when the blade slips down into a valley between two ridges instead of staying positioned in the desired line of the cut. Continue reading →
If you work with stained glass over time you can end up with buckets full of scrap. When the pieces start getting too small and irregular, or if there’s just too much of it, you can used them in a stepping stone. This tutorial demonstrates how to make a stepping stone with an abstract pattern. You can also use tiles instead of stained glass scraps.
Small mosaic plaques can be mounted on a wall with a the same type of hangers and wires used for paintings provided the nail on which it hangs is mounted in a stud inside the wall, and even then redundant wires and fasteners are recommended. However, larger mosaics need more robust mounting hardware. The “french cleat” is a type of wall mounting that can be used to securely affix heavy mirrors, cabinets or artwork to a wall. In addition to its strength, the french cleat also allows mosaic art to be mounted flush against the wall and makes leveling it easy.
For dry indoor mosaics, areas can be built up to support thinner tile next to thicker tile by mixing sand or sawdust to Weldbond adhesive to create a heavy paste. You can also fill holes in mosaic backers using this method. Sand is best for minimizing the contraction that happens as the glue dries, but sawdust can be used when weight is an issue.
For outdoor and wet mosaics, thinset mortar can be mixed with clean pea gravel to make a concrete. The pea gravel must be washed clean and dried to avoid contaminating the mortar, and we recommend screening the pea gravel and using only small pieces. Note that you cannot use sand because too much sand will overwhelm the mortar and make it crumbly.
Case Study: Stained Glass Mosaic Coffee Table
Stained Glass Mosaic Coffee Table by artist Holly LaBarre.
Recently our customer Holly LaBarre emailed us asking how to build up areas between wooden slats of a mosaic coffee table she was making. The design concept for the coffee table was to make it look like it was made from pallet wood or wooden planks and put stained glass mosaic between the planks. The problem was that the planks are significantly thicker than the stained glass, but Holly wanted the stained glass to flush with the planks so that the coffee table had a flat surface.
The solution was to put a piece of 1/2-inch plywood on the underside of the table top and then build up the area to be mosaiced using a paste of Weldbond and sand.
Mosaic backer built up. This photo shows one trough with an initial filling of paste. The other two troughs are still empty and show the plywood backer underneath the table top.
The catch is how to build up the area to the right height so that when the stained glass is applied, it isn’t too high or low. To figure this out, Holly made a simple gauge from a straight edged piece of wood that rests on the surrounding planks and has a small piece of stained glass glued to its bottom edge.
A simple gauge made from a straight-edged board and a piece of stained glass glued to the bottom shows how high the area needs to be built up. This photo shows that more paste needs to be added, probably 1/2 inch more.