Okay, so I'm NOT a resin expert, my dad is. I did not buy the resin, so I have no clue how much it cost, so I will not be able to give cost estimates for this project, only time estimates, so let's get started! I've been collecting bottle caps for different things for a while now for random things. On Pinterest (I know, who would have thunk, right?) I found bottle cap coasters and thought they would be perfect for a fun way of keeping the boy's furniture free of drink rings. I tried making them with polymer clay which gave me the opportunity to make sure that the bottom of the bottle cap didn't scratch his table (because, after all, that is the point of a coaster, to keep furniture nice). This did not work out. They broke and after Ryan tried them, he said he didn't like the way the bottles sat on the bottle caps. And then, he said something GENIUS (yup, I'm dating an awesome man). He said, "can you put them in something?" Immediately my gears started turning. I made a call to my father, the man who knows what type of material to use no matter what the project, and he said that I should use resin. I was going to head out the Michael's and buy some, but my dad was coming to visit that weekend and brought some for me. When I told him what I was doing, he even made a really cool mold for me (more about that in a minute). With all of this info, I went to work!
Catalyst for resin
Small plastic or plastic coated cups
Something disposable to stir with (I used popsicle sticks)
Optional: Resin colors
Edit: It might also be helpful to buy some curing agent for your resin. If you're using polyester resin like I did, your surfaces will likely be sticky and take a ton of crazy sanding to finish them off...
Get a Mold: Okay, you have a few options here. You can find a mold online or you can make one yourself. If you buy one, make sure that it's specifically for resin. If you're not careful during this entire process, your coasters will turn in to a sticky mess that you may never be able to get out of your mold. If you're super ambitious, you can make your own mold. I used this stuff because that's what my dad uses and he had it on hand, but you can use any other material that will work to make a resin mold. The way I made mine (or my dad made mine, thanks again!!!) was to make a small slab of clay that was 3.5"x3.5" and then making the mold. For those of you who have never made a resin mold before, I recommend just ordering one.
Spay Your Mold: Okay, this part is SUPER important. If you don't coat your mold with the spray mold release, it will not come out of the mold and you will have to buy/make a new one. Spray with mold release and let it dry. Don't coat it TOO much or you'll get filmy stuff coming off with your coasters.
Prep Your Bottle Caps: I saw one of these tutorials where she put the bottle caps face down, but I'm anal about the way I wanted this done and I wanted a nice coating on top the bottle caps. I also wanted to make sure that they were aligned the way I wanted them, which is REALLY hard to do when they're upside-down. Because of this, I wanted to put the bottle caps right side up, which would cause small problems. The bottle caps will easily trap air and float to the top unless you prep them. To do this, mix 1 oz of the resin (whichever resin you use, just follow the manufacturer's instructions to a T) and pour in to your 9 bottle caps. One oz is just about right to ensure you can get it in to all of the bottle caps. Let this sit for about 10 minutes. You want it to be extremely viscous (like almost hardened) before you flip them over. When doing this, use the manufacturer's instructions for the first layer of multilayer casting. Very often, resins are made in two parts, the resin and the catalyst. The more catalyst you put in, the quicker it will set, so for my resin, it needs 5 drops of the catalyst for 1 oz of resin for it to set quickly. This is what I used.
Pouring Your First Layer: After you've waited your ten minutes (or more), mix another ounce of resin at the ratio of resin to catalyst. Pour this in to the bottom layer of your mold and wait about 5 minutes.
Placing Bottle Caps: You can now turn your bottle caps right side up and start placing them. It's not super important to be careful during this step, but be sure that you don't push them all the way to the bottom (this is why you want to let the first layer set for a couple minutes before putting the bottle caps in). I started on the edges because it seemed to be the easiest way to ensure they didn't float into places I didn't want them to be. Now, give it some time for the bubbles to come out (unless you want bubbles).
Pour Your Last Layer of Resin: After having waited about 20 minutes or so for the bottom layer to set, make another 1.5 oz of resin with much less catalyst. The amount of catalyst you use will depend on your preferences. As I said earlier, the more catalyst you use, the quicker the resin will set, which may be to your liking, but the less catalyst you use, the easier it will be to remove bubbles. I liked the removal of bubbles method. Another hint for removing bubbles, let the resin sit for about 5 minutes and the bubbles will start congregating toward the center of the mold. Take a mechanical pencil and stick the lead out about 1/4". Use this lead to bring all of the bubbles in to the middle in to a big clump. Wait about 5 more minutes and the bubbles should have formed one big bubble that will be easy to pop with your lead.
Have a Super Awesome Coaster: Okay, there's a very long wait period here, but in about 24-48 hours, you will have super awesome coasters. I would not try to use them for about 48 hours. Since the resin is pretty thick, it will take a while for it to set fully. After 48 hours, you can enjoy your coasters as is or add little silicon feet from home depot to them.
One last thing before we go in to the time commitment, the resin is an irritant. I'm not kidding, it really is an irritant! Do this in a well ventilated area (sorry, roomie!) and wear some gloves. I promise, it will burn if you get this on your skin. It's not toxic, but it's definitely uncomfortable.
Mixing resin: Total time 5 minutes
Pouring resin: Total time 5 minutes
Removing bubbles: 10 minutes
Waiting: 48 hours
Start to finish, these won't be done for two days, but they really don't take that much time on your part and the resin that we got from Michael's is really user friendly, so I didn't have to deal with any initial user error.