The ceramic tile coasters that I crafted looked great initially, but very quickly got tea and coffee stains on them that wouldn't wipe off. Not being waterproof is a pretty serious problem for a coaster!
I'll share the secret with you on this page so you can learn how to make coasters that are beautiful, durable, and fully waterproof. It's actually pretty simple once you know how.
This is a long page, but don't let that frighten you. Learning how to make tile coasters is actually really easy.
How to Make Coasters: Materials
The first step in learning how to make coasters is to gather up your materials. Here's what you'll need...
Materials for tiles and decorating them
4 tiles each 4" (10 cm) square
Mod Podge or other white craft glue
Paint brush for spreading glue
Instead of using scrapbooking paper, you could use photos to make your own custom photo coasters.
Materials for varnishing and waterproofing the tiles
Achieving a waterproof and non-tacky finish is the the most critical part of how to make coasters in my opinion. Here's what you'll need
Two disposable plastic cups
Wooden stirring stick (e.g. popsicle stick)
The Envirotex is the secret of how to make coasters with a beautiful, glass-like, non-tacky, stain-proof finish. It's a two-part epoxy that comes in two bottles which you mix together then pour on your coasters. People use it to coat bar-tops in bars and restaurants so it's designed to be durable. One coat of Envirotex is equivalent to 50 coats of regular varnish. If you want to make a gift that will last for years, then it's worth using.
Before I discovered Envirotex I tried practically every other type of varnish (including acrylic varnish, decoupage varnish, spray-on polyurethane varnish, araldite, egg whites, and mod-podge), and nothing gave as good a finish. The other types of varnish looked OK, but they were tacky, or brittle, or got stained by coffee or tea.
I haven't seen Envirotex in craft stores, but you can get it at Amazon (link above), or on eBay (links below). Click on one of the links for more information about the product. A 8-oz kit (enough for 16 tiles) normally costs around $15, so it comes out at less than $1 / coaster. And obviously it's cheaper per tile if you buy it in bulk.
How to Make Coasters: Decorating
Cut out squares of scrapbooking paper (or photos) to decorate your coasters. My tiles are 4" across, so I cut out pieces of scrapbooking paper 3.5" across, to leave a small border around the edge.
Make sure your tiles are clean and dry. If they're greasy, then give them a wipe with methylated spirits or rubbing alcohol to clean them.
Completely paint the blank side of a decorative paper square with Mod Podge or white glue. Make sure you go right up to the edges. It's best to work on a piece of scrap paper that you don't mind getting glue on.
Place the glued piece of decorative paper onto a tile. Press on it firmly to remove any air bubbles. I recommend using a glass tumbler as a rolling pin and using a rolling motion from the center to the edge of the paper to work out any bubbles. The first time I did this I just used my fingers and even though I thought I was thorough I still left some bubbles under the paper which I only noticed once the glue was dry.
Repeat the process for the rest of the tiles. Have a cup of tea and a biscuit and wait 15 minutes for the glue to dry before going going on to the next step.
Check for any bubbles under the paper. If you see any, pop them with a pin and flatten them out.
Brush a layer of Mod Podge or white glue over the top of the decorative paper. I like to brush all in the same direction.
Wait until the glue dries clear (about 15 minutes), then paint on another layer, this time at right-angles to the first layer. It's really important that you completely seal over the paper with glue, so that later the varnish doesn't soak into the paper and discolor it.
Leave glue to dry overnight, so that it's completely dry before you apply the varnish in the next step.
How to Make Coasters: Waterproofing
I strongly recommend varnishing your tiles to make them waterproof. If you leave them unvarnished then they'll look OK, but they'll always have a slightly tacky (sticky) feel to them, and will stick to a hot cup placed on them. Also they'll stain if tea or coffee gets on them. Varnishing your tiles with Envirotex will give them a glass-like waterproof finish which I think is really worth it.
Mind you, the Envirotex epoxy varnish is going to drip everywhere when you pour it on your coasters, so before you start it's a good idea to:work on a disposable surface like a big piece of cardboard or several layers of newspaper
place each of your coasters on top of a disposable cup, to prevent them getting stuck to your work surface
put on some rubber gloves, because it's unhealthy to get epoxy on your skin
The Envirotex smells a bit so you might want to work in a room with an open window. It not anywhere near as stinky as spray-on varnish though.
Mark lines at 1oz and 2oz (30 mL and 60 mL) on one of your disposable plastic cups. That's assuming you're making 4 coasters, each 4" square. If you're making more or less, you'll need to follow the instructions on the Envirotex package for how much you'll need.
The way I marked the lines was to put exact amounts of water into the cup (usingdigital scales) and mark the level with a Sharpie marker. You could also use measuring spoons to measure out the water. Make sure you completely dry the cup afterwards.
Another option is to buy disposable measuring cups that already have measuring lines marked on them, but I figured I could just as easily make my own for cheaper.
Put the Envirotex bottles in a bath of warm (not hot) water to heat up.
While the bottles are warming up, cover the edges of the base of your tiles with adhesive tape, and trim any excess. This will make it easy to remove any drips of Envirotex later.
Pour 1oz (30 mL) from each Envirotex bottle into your measuring cup. Stir vigorously for 1 minute using a wooden paddle. After 1 minute, pour the mix into your 2nd cup, and stir vigorously for another minute. It's important to use two cups like this, because it leaves behind the unmixed epoxy on the sides of the first cup.
As soon as you've finished mixing the Envirotex, pour it onto the center of your coasters. Try to divide it evenly between all four. Notice how each coaster is balanced on top of a disposable cup to prevent it getting glued to the work surface.
The Envirotex will form spreading puddles on each tile and start dripping over the sides. Don't worry about the drips, they're a normal part of the process.
You want the Envirotex to completely cover each tile, so if it doesn't quite reach into the corners then use a scrap of cardboard to help spread it.
Also use a scrap of cardboard to make sure that the Envirotex completely covers the sides of each tile.
About 15 minutes after you poured the Envirotex, you will notice tiny bubbles rising to the surface. Breathe gently over the surface of each tile to pop the bubbles. It's the carbon dioxide in your breath that makes them pop. If you're nervous about putting your face too close to the tiles then you can breathe on them through a straw.
About 30 minutes after you poured the Envirotex, use a scrap of cardboard to wipe any drips from the bottom of the tiles. Wait another 30 minutes, and wipe away the drips again. By this stage you will have drips of Envirotex epoxy all over your work surface. I hope you protected it with newspaper or cardboard!
Cover your project with something (e.g. big cardboard box) to prevent dust landing on the coasters, and let the Envirotex cure for 24 hours.
Once the Envirotex has set, peel the adhesive tape (which will be covered in drips of Envirotex) off the bottom of the coasters.
If it's hard to remove the tape, you might need to first file the bottom edges of the tile with a nail file or sandpaper.
As a final touch, attach felt squares to the bottom of your coasters with glue or double sided tape. You could also use cork-board instead of felt.
Here are the finished coasters, ready to be given as a gift! The Envirotex coating cures to full strength and toughness about 72 hours (3 days) after pouring, at 70 degrees F (21 °C). After this time the coasters are ready to use. The cure time is slower at lower temperatures.
I hope you enjoyed learning how to make coasters and that you found my instructions clear. If you have any questions or comments, or just want to say hi, then please kindly leave a comment!! :)