Monthly Archives: April 2015

Stained Glass as Mosaic Tile: A Question of Styles

In my article Stained Glass Mosaic Art, I explained how stained glass can be cut up into small pieces and used like conventional tesserae or cut larger and used to define entire elements as is done in a stained glass window. In the window mode of working, one single piece of variegated glass is used to render an element, say a tree trunk for example, and whatever shading or detail is provided by the swirls or bands in the glass. Contrast that with conventional mosaic mode, where the shading or detail is built from different pieces of glass, and together they render the tree trunk.

The objection to working in the conventional mosaic mode is that most artists don’t want to lose all the visual interest of the swirls of color by cutting them up. Canadian artist Lorna Ball demonstrates that it is possible to use stained glass cut up into small tiles and not lose the visual interest provided by the variegated colors of the glass.

Grey Owl mosaic

Grey Owl mosaic by Artist Lorna Ball demonstrates that mosaic is a fine art where individual style can be expressed as fully as in painting.

Note the bark on the trees in the mosaic below. Sure, a single piece of swirled glass could be used for the trunks, but could any swirling no matter how beautiful capture the texture and dimension of the bark facets as well as Ball’s separate slivers of different colors do?

Up Through The Trees mosaic art

Up Through The Trees mosaic by Lorna Ball captures the essence of looking up from the forest floor. You can almost hear the birds up above in the canopy.

Lorna’s work also demonstrates an important point about using stained glass cut up into small tile: just because the tile is cut up small, it doesn’t have to be cut up into similar shapes and sizes. Notice in the mosaic below how the black tiles in the branches of the trees are completely different in shape and proportion from the white tiles in the tree trunks and from the yellow tiles that render the leaves:

Autumn Trees mosaic art

Autumn Trees mosaic by Lorna Ball makes successful use of different shaped tesserae.

The slender black tiles used for tree branches might make you wonder if the conventional mosaic style and the conventional stained glass style can be hybridized, and the answer is a qualified yes. For example, the above scene would have looked odd if the leaves of the canopy and forest floor were rendered in their tiny tiles and the tree trunks were replaced with single pieces of swirled glass. There has to be stylistic integrity throughout the composition, or the odd element will stick out like a sore thumb. The styles are simply too different. Look at the following mosaic by Natalija Moss as a reminder of how different these two stylistic modes are:

The Major mosaic art

The Major mosaic by Natalija Moss.

What if the blue strips of the background were rendered in smaller blue tiles in a conventional mosaic manner? Could the face still be composed from large pieces? No, the background would have more visual detail than the figure in the foreground, which is the exact opposite of what is needed to make the figure stand out from the background.

Mosaic Guitar

Artist MC Holt-Evans of Nashville recently made a mosaic sculpture very much in keeping with spirit of The Music City, and her mosaic guitar is worth taking a look at, especially if you are considering making a mosaic on an improvised base such as a musical instrument or a piece of furniture. The instructions below could be adapted for using other household objects as a base.

mosaic guitar back side

Mosaic guitar by MC Holt-Evans has a “blue grass” color scheme.

Mosaic Sculptures on Improvised Bases

Mosaic sculptures that use household objects as their base aren’t anything new. For example pique assiette (broken plate) mosaic furniture is fairly common, as are mosaic gazing spheres made from bowling balls. (Note that my article on gazing spheres explains why hard polystyrene makes a better base than a bowling ball.) However, a guitar can be a particularly challenging choice of mosaic base for several reasons: The shape is complex and curved, and part of it (the neck) is long and thin and has a lot of corners. The wood of the guitar’s sound box is thin, and yet it has a thick layer of lacquer that must be removed before adhesives and grout will bond to it.

Prepping the Guitar

Sanding

A medium grit sandpaper (120 grit) can be used to take off any lacquers or sealants. As always, wear an N95 rated dust mask for doing this type of work. (The N95 dust masks are cheap and readily available at a building material or hardware store.) I don’t recommend wet-sanding a guitar because you want to minimize its exposure to moisture until you get it sealed because the wood is thin and easily warped by moisture.

Modifying

Are you going to want to put the strings back on the guitar after it is mosaiced? Probably so, and that mean you need to take into account the thickness of the tile you are adding to the surface and raise the nut fret that separate the head from the neck. Use a hard wood for this such as bass (the wood used for sewing boxes and buttons) and not some soft wood like balsa.

Sealing

When you reseal the guitar with a water-based primer, you should apply two thin coats instead of one heavy one. To seal her guitar, Holt-Evans used an acrylic primer called Zinsser’s Bullseye 1-2-3 because it was recommended by an artist who works with mosaic guitars. Weldbond adhesive could also be used to seal/prime a guitar, and it might be the better choice because it is the adhesive that will be used to attach the tiles, and thus you wouldn’t have to worry about how well the adhesive and primer bonded to each other, but you would still need to give the sealing coat at least a week to dry out completely and fully harden before you tiled on it. Holt-Evans reported that she left coarse brush strokes in the sealant. This improves the bonding of adhesives and grout.

Using What You Have on Hand?

Be careful selecting a primer at random because Weldbond might not bond to some of them, definitely not oil-based materials. You want an acrylic, something like an artist’s gesso and not a latex house paint. PVA’s like Weldbond won’t bond to the vinyls and other binders in some house paint. Using what you have on hand isn’t necessarily being frugal if it doesn’t last nearly as long as it would have with the right stuff.

mosaic-guitar-start

The wood of the guitar was sanded bare and sealed with an acrylic primer in preparation for mosaic covering.

Mounting the Tile

Holt-Evans used Weldbond to attach the glass tile, penny rounds, and stained glass she used.

Partially Crushed Liquor Boxes

Use partially crushed liquor boxes to cradle the guitar or sculpture while you work on it. You can rearrange the boxes to re-position the guitar as needed so that whatever part of the curved surface you are working on is facing up.

Brush on the Adhesive and Let It Get Tacky

If you are having problems with tile sliding around, use a small paint brush to spread the Weldbond onto the surface and allow to sit for a few minutes and get tacky before you add the tile. Depending on how dry or moist your air is, this can be about 15 minutes, perhaps much faster if it is dry midwinter air and the heater is running. Remember, if you let the glue skin over too much, then it won’t bond to the glass as well.

Dental Picks and Cotton Swabs

Dental picks (or tooth picks) are invaluable for adjusting the positions of tiles without contaminating your fingertips. Cotton swabs can help clean up messes with precision and not move tile out of position. Tip: Don’t thow your wet-glue swabs into the trash. Instead, let them dry out and peel the dried glue off them next session and get another life out of them.

mosaic-guitar-progress

Mounting the tiles on the primed surfaces of the guitar.

Grouting

Grouting Studio or Bench Space

I like to grout outside on a patio or some place that can be hosed off. You can use drop cloths indoors, but you still have to be relatively neat, or you will track sand on the floor and ruin it. Grout and thinset mortar are concrete, not paint. That being said, grouting inside can be done without making a mess and is routinely done by mosaic artists. A plastic folding table or a table covered in construction plastic from the building material store is ideal for a project that might require multiple sessions to grout.

Grout Colors

Black grout makes color stand out more. All grout colors are lighter when the grout hardens, especially black grout. Black grout is usually jet black when mixed up but hardens to a charcoal gray or lighter. Pure white grout makes a mosaic look like a summer camp project.

Thinset Mortar vs Grout

I prefer thinset mortar instead of grout for projects like these. Thinset has an adhesive polymer in it that makes it strong and resistant to impact. Compared to ordinary concrete and grout, thinset is a lot less likely to crack and crumble when dropped. However, thinset contracts slightly as it cures, and so you might observe hairline cracks when used on a three dimensional object that can flex slightly, such as a wooden guitar. Like grout, thinset mortar can be dyed with concrete dyes.

Special Concerns

Grouting something like this is best done in multiple sessions. Unlike a mosaic chair or desk, a guitar has multiple places where special are has to be taken in order to not soil or clog some detail. A guitar has frets and working pegs and a saddle and a sound hole to take into account. Painter’s tape can be used to protect the bare wood inside the sound hole. Use crushed liquor boxes to cradle the guitar in different orientations while you grout it.

The color of a grout can look different if different amounts of water are used to mix up different batches or if they are misted differently. Try to mix up and handle your grout in a consistent way.

mosaic-guitar-finished

Finished mosaic guitar by artist MC Holt-Evans.

Grouting Sequence

Holt-Evans started by grouting the back of the guitar because it was the largest flat area with no obstructions and therefore the most straightforward surface to be grouted. When she grouted the back, she continued the grout over the sides so that there wouldn’t be a grout seam right at the corner because corners are vulnerable places and subject to many impacts.

The head and neck were each done in separate sessions, and for both of these elements, Holt-Evans did not take the mosaic and the grout around to the sides and backs. Only the top faces were covered, and so this meant that the grout had to be tapered off to the corner.

The front of the guitar was done in a later session because of the detail work required to get the grout tapered to the edge of the sound hole. The grout was carried down over the side to join the grout from the back on the sides.

To prevent a hairline crack where new grout meets the old, you should moisten the edge of the old grout with a little water on a cotton swab before grouting. This keeps the old grout from sucking all the water out of the new grout before it has a chance to harden.

Mosaic Bird Bath

Artist Lyn Richards sent me some pictures of the mosaic bird bath she made this past summer, and it is worth showing off. The floral design and the colors used in the mosaic were inspired by Van Gogh’s painting “Irises.”

mosaic-birdbath-close

Mosaic bird bath by artist Lyn Richards makes good use of contrasting colors and a Van-Gogh-inspired floral design that help integrate the bird bath with its surroundings. Note the use of an ordinary concrete stepping stone as a footing/base to keep the mosaic work separated from the soil. This is recommended because the acids in decaying organic matter slowly rot stone, concrete and grout.

Material List for a Mosaic Birdbath

Concrete Base

To make a mosaic bird bath such as this, you could use a ready-made concrete bird bath from a lawn and garden center, or you could make an original concrete sculpture if you are looking for something with a less conventional shape. Lyn used a ready-made concrete bird bath that came in two sections: a base column and a bowl.

Thinset Mortar and Tools

Thinset mortar should be used instead of adhesive for attaching the tile. A complete list of tools and materials for mixing thinset and for applying it is given in my instructions for using thinset mortar with glass tile. (Note the instructions were written for doing extremely detailed work, so I might make thinset seem much more difficult to use than it really is.) I have also written a page for how to keep your hands clean when using thinset.

 Glass Mosaic Tile

Glass mosaic tile in non-porous and so water can’t get inside it and freeze and crack it all to pieces. This makes glass superior to stone and ceramic tile when used outdoors. You can use any of the glass we sell. Lyn’s mosaic was made from different brands of 3/4 inch vitreous glass tile, metallic glass tile. iridescent glass, and stained glass.

To find out how much tile you need, you can divide your shape into component surfaces and use our mosaic tile estimator.  What do I mean by component surfaces? For estimation purposes, Lyn’s bath can be thought of as cylinder topped by a disk. The surface area of the cylinder is A = D*Pi*H, where D is the diameter, and Pi is 3.14, and H is the height. The surface area of the disk is A = Pi/4*D*D. Note that this time D is the diameter of the bowl and not the pedestal base. Remember to multiply the surface area of the disk by a factor of 2 because there is a top and a bottom.

As always, remember to inflate your estimate by 5 to 10% to account for cutting scrap and to provide a cushion for error in your estimates. I have always found that it is much better to have tile left over than it is to not have enough. Suppliers sell out from time to time, and the next manufacturer batch might not match what you already have, or at least match exactly. Also, leftover tile serves as inspiration and material for future projects.

Finding and Transferring Patterns

Lyn used Van Gogh’s painting “Irises” for her pattern. She drew the outline of the shapes (blades and petals) onto the concrete using a pencil, and then she went over that drawing with a black Sharpie marker when she was sure she had her lines correct. This is recommended: Don’t use the marker until I work out my lines by trial and error using a pencil. If your pencil drawing gets to be a mess and you need to start over, you can “erase” it by wet sanding it and wiping it off with a rag.

mosaic-birdbath-side-d1

To create a sense of depth and shading, Lyn used multiple shades and hues of green for the leaves of the irises instead of one color.

Choice of Colors and Visual Interest

Note how Lyn used multiple shades and hues of green to make the blades of the iris leaves instead of using just one type of green. This creates shade and depth and visual interest and makes all the difference in the world. Monochromatic color fields are boring, and they take just as long to tile as a more interesting mix of colors. Note the solitary pea green blade of new growth and how it stands out from the other leaves, which are a mix of darker and bluer greens. Similarly, the petals of the irises are made from multiple cyan blues and ultramarine blues instead of one color, and this makes them more lifelike and more visually appealing.

Andamento and Visual Interest

The background of a mosaic is an opportunity to add visual interest to the scene and should never be “bricked” up like the tiled wall of a shower. Andamento is the visual flow of a mosaic created by arranging the tile in rows, and it can make the background of your mosaic as visually interesting as the figures in the foreground.

mosaic-birdbath-top-det

Lyn’s strong use of andamento creates a sense of motion in the background. When used to its full potential, andamento can make the background as interesting as any figure in the foreground, as demonstrated here.

Observe how Lyn used multiple related hues for the background instead of one color. Also note there is not a single whole tile mixed in with all these cut pieces. Why not? A uniform square would stick out like a sore thumb among all the irregular pieces.

Cutting and Attaching the Tiles

Thinset is concrete that hardens over time. I can usually get three hours out of a batch, and I often work in sections, usually completing about 1 or 2 square feet per session, depending on how detailed my work is. Lyn found it useful to have her tile cut up in advance of a session, but you can always make incidental cuts as needed while you are attaching tile. Again, my thinset instructions explain the details of how to handle and use the mortar to attach tiles. Tip: partially crushed liquor boxes make great cradles for holding heavy pieces of stone and concrete while you tile them.

Removing Sharp Edges

A marble file or a rubbing stone can by used before the tile is mounted to remove any sharp edges. After the tile is mounted, it is a little more difficult to remove sharp edges, but gently rubbing the surface of your mosaic with a rubbing stone can help a lot.

Grouting

Before grouting, you should clean off any excess thinset from the face of the tiles. Scraping this off will also make any loose tiles fall off so that you can reattach them before grouting. You should wait a day or two before grouting to let the thinset harden. Black grout is best for making your colors stand out. Lyn used a combination of black, gray, and brown grouts, and she blended these to get the exact color she wanted. A few days after your grout hardens, you should buff all the grout haze off and seal the finished mosaic with multiple applications of a silicone-based tile and grout sealer, such as available at any building material store.

mosaic-birdbath-full-2

Lyn Richard’s mosaic bird bath at home in her garden.