Man Cave Resin Coasters




About: I'm a 20-something chemistry graduate student and jewelry artist. I love to make things over buying them. My main media are metal and clay, although I dabble in a bit of everything. Most of my jewelry is fol...

I have a minor obsession with Pinterest, so after seeing a set of bottle cap coasters that looked like they might scratch the table, I said, "I can do that better!" Well, with a little help from the recipient of this gift and a couple failed attempts at other options, I chose resin casting to make these super awesome coasters. A great way to show the man in your life that you care, these fun coasters are easy to complete, done in about 4 days (assuming you only have 1 mold) and don't take that much active time on your part.

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Step 1: Materials List

What you'll need:
Casting resin
Resin catalyst
Resin mold
Mold release
Plastic or plastic coated cups to mix in
Something disposable to mix with (I used popsicle sticks)
A well ventilated area
Bottle caps to set in the resin

If you want your coasters to be colored, you can get resin dyes as well.

Links above are just some places that I have found these items, not necessarily where I got them from.

Step 2: Get a Mold and Prep It

There are two different 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. This is important because if you use the wrong type of mold, you may never get your coasters out. If you want to make the mold yourself, you can use whatever type of mold material that you're used to, so long as it's usable for resin. I was lucky enough to convince my father to make a mold for me using this stuff. I asked him to make a 3.5"x3.5" mold which fit nine bottle caps pretty perfectly. I won't go in to how to make the mold because I don't really know how to.

To prep your mold, spray a thin coat of mold release on your mold. Let it dry before casting your resin. 

Step 3: Prep Your Bottle Caps

If your mold is clear, you can place your bottle caps upside-down during the next step and skip this step. Because my mold is extremely opaque, though, it would have been impossible to see the positioning of the bottle caps from the bottom side of the mold. Because of this, I had to set the bottle caps right-side-up rather than upside-down. If you try to do this without prepping the bottle caps slightly, they will float and casting these will be much harder. To prep the bottle caps, I turned them over and filled them all with resin. Approximately 1 oz of resin was enough to fill nine bottle caps. By doing this, you ensure that you won't get your bottle caps floating to the top of the coasters. Let these set for about 10-20 minutes before moving on to the next step.

Step 4: Pour the First Layer of Resin

Now it's time for us to start the actual casting. Mix about an ounce of resin using the manufacturer's instruction for multilayer casting. The stuff I used said to add 5 drops of catalyst for every ounce of resin for the first layer, so that's what I did. When mixing the resin, you will get a lot of bubbles. I read a lot on the internet about using a blow torch or a straw to get out all of the bubbles. I found that the best way to do this was to let the resin sit for about 5 minutes. This lets the bubbles collect toward the center of the mold and then I grabbed a mechanical pencil, pushed the lead out about 1/4", and moved all the bubbles in to the center of the mold. I gave it another 5 minutes for the bubbles become one big bubble and then popped it with the pencil lead. Before moving on to the next step, wait about 20 minutes from the time that you initially poured this layer of resin.

Step 5: Insert Your Bottle Caps and Pour the Top Layer of Resin

Flip your bottle caps over and place them in the resin. The bottom layer of resin will be a little sticky now, so be careful of how you place them. Place them in the exact places that you want them. After you're done placing the bottle caps, mix another 1.5 oz of resin using a lower amount of catalyst per ounce. I used approximately 3 drops per ounce, so a total of 5 drops for the 1.5 oz. The less catalyst you use, the easier it will be to remove the bubbles. Pour this mixed resin over the bottle caps ensuring that you've covered all of your bottle caps. If you haven't, just mix up some more and add it to the top. Use the same technique you used in the last step to get the bubbles out of the resin. Leave this sitting in the mold at least over night. The resin will not be hard enough to use as a coaster for about 2 days. 

Step 6: Finishing Your Coasters

This is a new step as of 4/25/12. I had been asked about how to finish the coasters, so I'll tell you exactly how to do it. The only thing you need that isn't on the original materials list is sand paper and an object to elevate the coaster (see picture picture). The sand paper should be no coarser than 200 grit and the object should be at least an inch high tall and small enough that all 4 edges of your coaster can hang over the sides after being placed on top of them.

To make your coasters smooth, use your sandpaper to remove any bubbles or imperfections (aka the meniscus that has formed around the top rim of the coaster) that may have appeared during the initial pouring. I used 220 grit sand paper. It's not extremely important what grit you use, but I wouldn't go any courser than a 200 grit. All you want is to remove the bubbles and not make scratches that are too deep. Once you've sanded the bubbles and imperfections out, wash the coaster in water to remove all of the resin dust. Make sure that it's clean. The dust left on the coaster will get embedded in to the coaster after you put the next layer of resin on and will make this step useless. After completely drying the coasters, place some paper on your work surface to keep it clean. On top of the paper, place your coaster on top of the object mentioned earlier (see picture again). Mix up another ounce of resin using about double the catalyst that you used for the base layer of the coaster (I used 10 drops of catalyst for 1 oz of resin). Pour a thin layer on top of the coaster. You can smooth it out to the edges using your stirrer. Once you've made a nice coat on top, coat the sides by using your stirrer to place the resin on the sides of the coaster. It will drip, which is why you covered your work surface and used something to elevate the coasters. After about 5 minutes, use a popsicle stick or anything else that you can throw away to remove the beads of resin that have pooled on the underside of the coaster on each of the 4 sides. You now have removed most of your imperfections. Pictures 4 and 5 of this step show bubbles on the side of the stone coaster and their appearance after the first coat of finishing resin. It's likely that I will have to repeat this step (at least for that coaster), but it's definitely an major improvement.

Step 7: Enjoy Your New Coasters

Now you have a super awesome coaster! If you're still worried about it scratching your table, you can go out and buy silicon pads at Home Depot for the bottom of the coasters. They're super cheap and clear, so you should not see them after you put them on the bottom of the coaster.

Thanks for reading!

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    35 Discussions

    This is about as close as I could find commercially:

    It's a 3"x3" mold and you could easily bend in some of the ridging on the caps to make them fit, but if you want a 3.5" square, you'll likely have to make it. This was the stuff we used to make the mold:

    We rolled a small slab of air dry clay, cut it to a 3.5" square and let it dry for 24 hours. We then made a well for the resin mold using strips of oil based clay (so that it wouldn't dry out). We put the strips vertically around the piece of clay, mixed the mold material and made the mold. I'm very much that person who says, "well, they don't have it. Let's make it!" Hope this helps! If you need any more help, feel free to contact me.


    Reply 2 years ago

    Is oil-based clay that molding clay that is very stiff and never dries? Could you have made the entire mold out of molding clay?


    Reply 7 years ago on Introduction

    Sorry it took me so long to respond... I'm not sure how well the mold release would work with plaster, but I do have some on hand and would be willing to try it when I finally get home from summer stuff. If you'd like, I can let you know how it goes. My email is allenamistral(at)gmail(dot)com. You can email me there and I'll be more than happy to let you know how it goes!


    Reply 2 years ago

    Just blue sky thinking, but could the plaster be waxed first, and then a release agent used, before using it as a mold for resin?


    6 years ago on Introduction

    I just made mine last saturday... for some reason the top surface is sticky an seems like it didn't dry.. what have I done wrong?

    2 replies

    Reply 6 years ago on Introduction

    Hi Jokski! Sorry it took me so long to get back to you. So the resin will not cure entirely on the surface without the curing agent which I apparently so awesomely forgot to mention. That being said, you can easily sand your coasters with either a power sander or normal sanding block. It's only the outer surface that is sticky.


    Reply 2 years ago

    I'm new to this. Would it be possible to put a little curing agent on the sticky resin to make it cure and stop being sticky?


    3 years ago

    I just learned on another site that you can use cooking spray as a cheap mold release agent. You spray it in, wipe out the excess and there you go. My resin hasn't even arrived from eBay yet so I'm in the very early stages of the hobby.


    4 years ago on Introduction

    Nice, I have been making bottle cap coasters as well. I just posted/finished my instructable. I route a piece of wood and use epoxy resin instead of a mold and casting resin. Here's a pic and the link if you and anyone else is interested:


    4 years ago on Introduction

    I just made my first set and I've found that the coasters are super smooth and not very effective for holding a glass as they tend to slide. Any suggestions on how to manage it so that they are not so slippery?

    For each coaster, I used about 3.5 oz of resin. So for a set of 4, that would be a little less than 15 oz. If this is your first time with resin, I would plan for a few mess ups as well, so I would get something close to 20 oz for a full set of 4.

    Heads up for people who are having trouble getting a mold for this project: No need to make or buy a fancy mold! You can literally use anything square and plastic e.g. jewelry box, smooth tupperware, plastic shell packaging from a toy, etc. I had a small travel first aid kit at home, the size was almost exactly 3.5in x 3.5in and I used that and it worked perfectly! You can get one from local pharmacy (walgreens, cvs, etc.) for less than $2. Just spray a little extra mold release at the beginning and make sure the surface gets thoroughly coated and you are good to go!

    1 reply

    Be careful though as porous material will absorb the mold release agent. Since you have to let it cure for 24 hours, things like plaster and other porous materials will not work for a mold.


    7 years ago on Introduction

    YES! a fellow stone drinker! It's always nice to see a beer drinker with good taste. I need to make some of these... It will pair amazingly with my folding bottle opener! check out the instructable here!

    I finally edited the instructable to include my method of finishing the coasters. Sorry it took so long! I'm a full time employee and student at the University, so I don't get much time during the week.

    Thanks, technofossil! The edges are a little rough. There are some good tips on resin polishing here. I did have to sand the edges down, so I'm hoping to try these polishing techniques soon. I think I'll try the one with the rotary tool, since they're small and I have one. Once I find out how it works, I'll make an edit to the instructable.