Stainless Steel Tile Molds
Stainless steel has a bit of a mythical place in the glass world, it’s great for molds, difficult to work with, expensive as all get out. Some of these things aren’t necessarily true. Stainless can be easy to work with, and a very useful thing indeed.
A few years ago, I had a client that wanted custom made recycled glass tile for her bathroom. The tile would be made with the wine bottles she saved up, which would be ground, filtered and the frit custom mixed to make colors, and then fused into tile shapes. Which meant I needed a bunch of custom sized tile molds. I had experimented with ceramic tile molds, which worked well, but were time consuming to make.
Since, conveniently, our kitchen garbage can pedal had just broken, I had some stainless steel on hand.
Although the manufacturer doesn’t say how thick the steel is, it feels somewhere in the 18-20 gauge. You can purchase sheet stainless steel online, and if you have a metals dealer in your area, perhaps even locally. And, if you ever see a stainless steel garbage can at a thrift store or yard sale, snap it up!!
So, to make your own tile molds, disassemble the garbage can and flatten out the steel the best you can. To make a tile mold, you’ll need:
Stainless steel sheet
Aviation snips or sheet metal shears
GLOVES
Ruler
Marker
Small Drywall Square
You’ll need piece of stainless at least two inches larger in each direction than the tile. I am making a 2″ x 4″ mold today, so I need a 4″ x 6″ piece of stainless steel. First I’m going to square up the steel using my handy dandy square:
Now that I have a square edge, I’ll measure in 1″ for the vertical side of the mold, then over 2″ for the bottom of the mold, and another 1″ for the other vertical side. 
And then use my square to extend the lines across the whole steel sheet. Notice that the right hand side of the metal isn’t cut perfectly straight. This is okay because it will end up being the top of the vertical side of the mold and won’t affect the tile at all. 
Now, I’ll mark the long side of the mold by measuring in 1″ for the vertical side, up 4″ for the tile part, and then another 1″ for the other vertical side. 
and again extend all the lines: 
Now, using my Aviation Snips, I’ll trim off the extra stainless steel: 
Now, we need to create sloped vertical sides for the mold that well close neatly on the corners, yet allow some flexibility to allow the glass to expand and contract during firing. We’ll do that by cutting out the corners at an angle. Using your square, mark a point halfway between the corner of the tile mold and the next blue line: 
Do this for all four corners, on all four sides. Then draw a line from the intersection of the vertical and horizontal blue lines to the new marks (that sounds complicated, but it isn’t) 
Do the same for the other 3 corners. Now, cut out that kite shaped section of each corner with the aviation snips: 
After all four corners are trimmed out, we’re going to fold up the sides of the tile mold. I recommend using gloves for this part, the cut edges of the stainless mold can be sharp.
Using a solid straight edge (I’m using my square), set the straight edge along one of the long sides of the tile mold, on the blue line. This edge will help you make a nice straight fold.
Keeping the square firmly in place, fold up the side of the tile mold. It doesn’t have to be completely vertical, we’ll adjust it a little later.
Now do the same thing to the other long side. Once that is done, we’ll do the short sides. Now, you’ll notice that we can’t do the short sides just the same way, since the pointy bits of the long sides are in the way. So, I’ll use the corner of my square and fold it one bit at a time:
Now, all four sides should be sorta vertical
Still with your gloves on, carefully fold each side so the corners touch, they won’t seal perfectly, but you can do a pretty good job:
These can now be kiln washed or sprayed with Boron Nitride and used to fuse recycled glass into tile. If the kiln wash doesn’t stick, you can try adding a drop of dish soap to your kiln wash, or run the tile molds through a firing empty, they will oxidize slightly and the kiln wash will stick better. Here is a picture of my molds mid use:
Stainless Steel Tile Molds
Filled Stainless Steel Tile Molds 1″ x 6″