|Making Mosaic Stepping Stones
When we first started making stepping stones for the garden using glass we didn't
even know that there were books on the subject. Peg had been into stained glass
for some time and had made some beautiful panels both for ourselves and relatives.
When you do a lot of panels, you end up with buckets full of scrap glass.
We wondered, "what can we do with some of this stuff?" (we tend not to throw
anything away!) We had seen some nice stepping stones in the garden centers with
rock and sometimes seashells pressed into them and that's where "our" using
the glass idea was born. We whipped up a few small stones to try it out, ended
up tossing some because they didn't turn out right, and decided to go searching.
What we found was that most stained glass retailers were already supplying books and glass and molds for doing this! "Great," we thought. We can do that. How we missed the books and molds in the first place we still are not quite sure--having bought lots of glass and supplies for other projects. OK Charlie, get to the point.
Yeah. The point is, none of the books we have "found" tell you ALL of the story. Some have part of the info you need, some others might offer a tip or two on getting started. The short of it being--everyone has their own techniques for getting these things made, and for us it still ended up a trial and error thing until we got good results. So for what it's worth, here's what works for us. Maybe we can save you some time and aggravation and have your #1 stone come out right!
The mold - The most important part of the whole project. You can buy molds at stained-glass suppliers in all kinds of shapes. Hearts, rounds, squares, half moons, six or eight sided, etc... but you can also use large plastic containers like tupperware or rubbermaid or such. For our first projects we used both a 1 foot square and round plastic container. A 1 foot diameter is about the smallest size practical for an actual stepper, but you can make them "brick size" too and use them as ornaments, accents, or whatever.
You can make molds from wood by starting with a small piece of plywood--3/8" minimum thickness--in the shape you want and tacking on sides made from 1x3 stock (nominal size, 3/4" x 2-1/2") Unless you're a whiz at woodworking, I'd stick to straight sided shapes. If you do this, it would be great to have access to a table saw so you can rip a 7 degree bevel into your sides. The beveled edge would then go on the inside of your mold to promote easy release of the stone (and it'll make the stone look better too). You can also use screws to attach your sides which can make mold release a breeze by removing a side or two when the concrete is dry. Depending on how proficient a woodworker you are, you can conceivably make a mold in any shape you want! Now you have a mold.
The glass - If you're already cutting stained glass, then skip this part! You know what you need to do. I won't go into actually cutting the glass. You can find lots of resources explaining how to use a glass cutter, the scoring-snap method, scoring-tap-snap method, using a glass grinder or special glass band saw, etc. Practice some cuts and go for it. Which ever way you go, remember safety first!
If you're using a pattern from a book, make sure it fits the mold. Make sure that when you cut out your patterns that you can maintain uniform spacing between the pieces and still maintain the integrity of the pattern. Peg checks this carefully. Sometimes even patterns intended for a particular mold look out of whack if your spacing between pattern pieces change. Sometimes, you will want to adjust the spacing yourself. This is especially true if you are modifying a pattern intended for a foiled/soldered panel. The "rose" you thought you were making might end up a tulip if the relationship between pieces goes awry. We've read and heard different ways to do this including cutting out the pattern pieces with special-wide scissors!(pattern shears) Another way is to take the pattern to a copy machine, reduce it to fit the bottom of your mold minus a ½ to 5/8" allowance on all sides before you cut your pieces out. A new one Peg is working on now was reduced about 8% to get it to both fit the mold and maintain the relationship between the pieces. Tip Children's coloring books are a good source for designs. After the pattern is the proper size and proportion, the actual pattern construction begins. Make an exact copy of your finished pattern and cut the pieces apart trimming 1/8 to 1/4" off all outside edges. On VERY small or thin area pieces, we often elect to do more trimming on the adjacent pieces and leave the little one almost intact. We have tried reducing the final pattern slightly on the copy machine, then cutting this apart to use for the individual pieces. Any pattern with curves WILL NOT WORK because of the changing spatial relationship between the pieces. (The straight-sided sun burst in the film strip was done in this manner and it came out just fine.)
If you want to get a fast start, try the freeform method, and pick out pieces of glass (or cut some easy triangles and shapes) that suggest flowers or whatever shape you've decided on. We've done lots this way including the daffodils stone, lighthouses, ships at sea, whatever you can dream up.
Okay? Now you have your glass.
Next step. Grease up that mold! We use Vaseline. Smear it all around the mold, especially the sides and where the sides meet the bottom. When tip out time comes, you'll be glad you did!
Don't know where this tip came from, maybe a book, but it's one that will save you much cursing! You can't possibly put your glass in the mold and pour mortar and concrete on it and expect the pieces to stay put. Sticky shelf paper to the rescue! We use the clear plastic variety so you can see what you're doing, but any will work in one of the following ways.
1. NOT CLEAR - Cut a piece of the shelf paper a little smaller than the mold, lay it in the mold sticky side UP and go ahead and put your glass in place REVERSING the pattern you've chosen. That is to say, the side you want showing on the stone will be DOWN, the back side of the glass will be UP. Position the pieces as necessary until it looks as you intended only in reverse.
2. CLEAR - Same as above, cut the paper a little smaller than the mold but this time set it aside. Go ahead and put your pattern together, either in the mold or out, the side you want to see on the stone should be UP. (This method works better when you've got a busy pattern that would take some thinking about to reverse or put together upside down.) When it's all assembled take the sticky paper and STICK it right on top of your pattern. Press firmly making sure each piece makes contact as you will now FLIP this whole thing over into the mold. Center it up in the mold and you're almost there.
The mortar - We use straight "out of the bag" mortar mix for the first pour. You can buy this everywhere in 40/60/80 lb bags. You need this fine mixture to ensure filling of the spaces between your glass pieces. Follow the directions on the bag, and mix about a quarter to a third of a 5 gallon plastic bucket full of mortar mix for a standard 14 to 16 inch mold. A little less or a little more depends on the size of your mold. You will have to experiment and will gain expertise as you make the stones and will be able to "eyeball" the right amount after a while. Add water a little at a time until the mortar is say, "mayonnaise" consistency. Carefully spoon, trowel or whatever into the mold starting at the EDGES first. This will help keep the shelf paper with glass attached from shifting. Continue until the glass is covered to a depth of 3/4 -1". For stepping stones that are likely to see some actual stepping activity, IE not just a pretty face, we recommend cutting a piece of ½ mesh (or more) rabbit wire or other fencing wire smaller than the mold by about 2 inches on a side. Place this in the mold on top of your mortar, making sure it is flat with no protrusions that will show. Now, on to the concrete! Again, use the premixed stuff right out of the bag. Remember, mortar is a cement mix that's smooth, used typically for setting brick and block. It has good adhesion but is short on strength when used in large areas. Concrete has a slightly different mix of Portland cement and contains small rocks or gravel. It is extremely strong in large areas. This is what we want for a stepping stone. Mix as directed, eyeball the amount based on your first pour, and top off the mold with this mixture, again starting from the edges and working in. Pat, tap, shake (not too hard) or do whatever it takes to get the air out and to make sure there are no spaces along the sides of your project. Now you're really almost done!
Wait three days! Well that's what the books all say. You will find that it all depends what time of year you pour your project, the viscosity of your cement mixes and a whole lot of other variables. After you "do" a couple, you will know when "the right time" for "tipping out" arrives. Turn the mold over and peel off the shelf paper covering your masterpiece. Do not be horrified if it looks less than you expected at this point. Even after a three day "set", you will be able to wipe things clean with a wet sponge or towel. Fill in any impfections, if you have any, with a small amount of mortar mix and let dry. If it looks like a stone, than it must be a stepping stone! Congratulations, you've done one...the rest will be magnificent!
Jury still out - To seal or not to seal--with a waterproof sealer.. Some sources will tell you to go ahead and paint them over with a good quality exterior sealer to keep the water and elements from penetrating your stone. But this we know to be true, if water gets into an outdoor fixture, then it should also be able to get out. We DON'T seal ours generally, and if we do, we only seal the top to help preserve any special pattern that we would like not to wear as much. The stones in the gallery are over three years old and have not been sealed..
This text is a first draft and will likely be modified. Please come aboard often!
Copyright © 1999 Chuck & Peg Diem all rights reserved.