I wish I could say that resin casting is a cheap and easy way to satisfy your crafty urges. Sadly, I can’t. Like so many hobbies (knitting, anyone?) it seems like you can try it out without a big investment, but it quickly starts to add up. So why do it? Because you can make some really cool stuff, and you get to pretend you are a mad scientist in the process.
To give you an idea of what kind of investment I’m talking about, here is the pile of stuff I used while making this tutorial:
- Freezer paper – Hands down the best thing to protect your work surfaces while doing anything crafty.
- Silicone molds – I’ve used cheaper molds, but silicone never bonds with the resin and it comes in all sorts of cool shapes.
- Resin tints – you can use all kinds of solids to color the clear resin, my favorites are candy sprinkles, glitter and old makeup, but for today’s purposes, I need the actual dye.
- Pearl powder – because I think it will look cool.
- Toothpicks – for mixing the tints.
- Popsicle sticks – for mixing the resin.
- Plastic cups – for mixing in.
- Plastic cup with fluid measures marked on the side – I use this to help me figure out how much of each color to mix, but I ran out of these cups, so it’s just taking up space right now.
- Needle-nose bottles – to make getting the resin into the molds easier (I didn’t end up using them this time, I just poured straight from the cups).
- Rubber gloves – because this stuff is kind of nasty.
Oh, and the actual resin.
SO, step one was to get most of this stuff out of my way. A clean work area makes a world of difference. My resin of choice is a clear, low-odor, one-to-one resin. This means that you use equal parts resin and hardener. It costs about the same as the stuff that only takes a few drops of hardener, but it doesn’t give me dizzy spells and it produces much less heat than the other (the hardening process causes an exothermic reaction which can get hot enough to crack your finished product, or melt through a plastic mixing cup if you leave it too long). The one drawback is that it takes longer to cure. You can touch it after about twelve hours, but it doesn’t stop being flexible for a full 24.
Normally, I am a “glance at the directions and fake it” kind of girl, but when it comes to the resin, it is worth it to read them through and through. The most important thing is getting your measurements right. It has to be as close to a 1:1 ratio as humanly possible. I usually mix up small batches, 3-5 ounces at a time, to make things easier. It won’t harden if you take time to mix a bunch of colors or you get interrupted, but I have found that trying to do a full 8 ounces worth all at once takes just long enough for the resin to start to thicken and thick resin is a pain to work with.
To mix, pour your resin in one cup, and then pour an equal amount of hardener in the other. Pour one cup into the other, scraping as much as possible off the sides, and mix for two minutes. Do not hold it right under your face and look down into the cup while you mix, you will get a headache from the fumes. After mixing for two minutes, pour everything back into the other, mostly empty cup, and mix for about another minute. This technique is called “boxing” and it is the surest way to mix two somethings together evenly.*
Now it’s time to get all Marble Slab up in here and choose your mix-ins. Like I said, candy and glitter work great,** but I used opaque resin tint this time. It costs about $5 a bottle, but you only use a few drops at a time, so it is worth the investment if you plan to do a lot of casting. I love mixing colors. The one caveat is that you can’t use too much color, and the color itself must be mixed well, or it will throw off the curing process. I once forgot to mix my yellow before I started tinting and my yellow, orange and green things all had the consistency of old chewing up gum – kind of stretchy and prone to snap if you stretch too far. After this, I added the toothpicks to my toolbox to stir up the tiny bottles.
OK, colors are mixed, it’s time to pour! Pour slowly. If the mold is large or has lots of nooks and crannies, it works better to pour into all the different areas, instead of pouring in the middle and letting it spread. It’s hard for me to estimate precisely how much resin I will need for each of my “scheduled” projects, so I always get out a spare mold for extras. In this casting, I want to make Han Solo trapped in carbonite, a few retro robots and a full tray of aliens. I also have my punctuation mold out for whatever I have left over. Waste not, want not.
Sometimes mistakes happen. Case in point, I left the stir stick in my cup of orange while I poured, and I managed to flip the stick out while I poured and got orange into the red cavity and the yellow cavity. Awesome! Really, it’s not a big deal. Whenever I make a mistake, I treat it as an experimental piece. If there’s something I’ve been wondering about, I’ll go ahead and do it, because why not? It’s not going to come out the way I wanted anyway, I may as well try to learn something from it.
Once everything is poured, you may notice tiny bubbles on the surface. This is what the drinking straw is for. Blow gently on the bubbles and they fizzle right away. You may think you don’t need the straw, that you can just blow on them and get the bubbles out. It doesn’t work. The straw makes all the difference.
Once everything is poured, make sure it is in a safe place*** and leave it entirely alone for 24 hours. Come back the next day, pop them out and you’re done. Right?
During the curing process, the resin expands a little and then contracts, leaving you with this fun little edge, which I believe is sharp enough to slice cheese. Because I have no desire to injure anyone who gets one of my resin pieces, I sand off the pointy parts. I don’t try to sand everything perfectly flat for a couple of reasons: 1) it’s actually quite a bit of sanding to get everything perfectly flat, and B) the pretty shiny back gets scratched up and crappy looking in the process. A blunt, slightly raised edge, looks better than a scratched up backside. I have discovered, through painful trial and error, that it is easier to hold the sandpaper flat and rub the resin across it, instead of trying to hold the little piece of plastic and rub the sandpaper along all the edges neatly.
Once everything is sanded, I’ll go in and add whatever painted details I want to do. In some cases, no extra details are necessary. Han Solo looks just fine with his carbonite self untouched, but I like to color in the eyes of my alien guys and the retro robots get all sorts of fun details. This is actually one of my favorite parts. I have never painted two robots the same, so each is unique. This can be a pain if I am feeling uninspired and I can’t remember which colors I like best where, but it comes in handy sometimes. If, and this is entirely hypothetical, your paint pen suddenly decides to take a giant dump, flooding a whole chest panel with blue instead of just the little dial you were trying to paint, you can say “I meant to do that” and run with it.
After the details, it’s time for the clear coat. Almost everything I do has a clear coat, whether or not it has painted details. If you use a matte finish mold, and most of the silicone molds are matte, then the resin will have a matte finish when it comes out. If you have anything like glitter or pearl powder in the mix, you will need to give it a coat of glossy or satin spray to bring out the sparkle. Sometimes I coat the back as well as the front, sometimes I don’t. It depends largely on how I feel. If you are going to do both sides, spray the back first and the front after the back has dried. This lessens the chance of getting some random outdoor debris stuck in the finish of the front side.****
And now, finally, you are done! Unless you ate attaching hardware, of course. I haven’t decided what will be keychains and what will be magnets out of this batch, so I’m not doing that part yet. For keychains or pendants, I drill a tiny hole in the top of the piece and screw in a small eyelet. Drilling the pilot hole keeps you from cracking the plastic when you screw in the eyelet. If you are going with a magnet, all you need is a dab of superglue and you are good to go. I usually spring for the high-powered magnets because the resin is a little heavy for most craft store magnets and they won’t hold up a piece of paper on the fridge. A magnet that won’t hold up a single piece of paper is dead to me.
And there you have it. It is kind of a pain in the ass process, and it ends up taking about two days for me to do it right, but I enjoy it nonetheless. Like I said at the beginning, it makes me feel like a hybrid artist/mad scientist, and I can think of no other way to take eight ounces of goo and turn it into six Han Solos, four sets of Rainbow Alien Love, two Retro Robots and a pile of miscellaneous punctuation.
*You can also do this with paint, if you are painting a room large enough to take more than one gallon of paint. That way you don’t end up with half the room looking just a hair lighter than the other half.
**When you use a solid for coloring, be it super-fine pearl powder or candy pieces, all the particulate will sink to the bottom, which is the top when you take it out of the mold, while it cures. You can get away with using less, because you know it will all end up front and center, but if you are using a colored resin and a different color solid hoping for a two-tone effect, all you really see is the solid.
***If you are using a flexible mold and you know you will have to move them, you may want to put everything on a cookie sheet first, so you can just move the cookie sheet and lessen your chances of spilling.
****Unless you are fortunate enough to have an indoor clean room set up for painting, in which case, good on ya.