Resin on Polymer Clay

My experiences with resin started when I was trying to put an even coat of resin on a curved cabochon with EnviroTex Jewelry Resin.  The resin looked perfect when wet, but as it dried, the top developed bare spots and the sides were thick with sagging resin.  I tried another coat and it smoothed it out somewhat, but I thought there must be a better way.

To figure this out, I bought the following brands of epoxy resin and a UV lamp and commenced testing.

1. Alumilite Amazing Clear Cast
2. Cernit Kit Finish Glass
3. EnviroTex Jewelry Resin
4. EnviroTex Lite Pour-On High Gloss Finish
5. Ice Resin Jeweler’s Grade
6. Lisa Pavelka’s Magic Glos – UV
7. UltraDome UV Epoxy – UV
8. Art Resin
9. Little Windows
10. Resin Obsession
11. Pandora Deep Shine – UV
12. Chinese resin from Amazon (I don’t know if it has a brand name) – UV

Most in the list above are two-part resins.  There are two bottles of liquid (resin and hardener) that you mix together and let cure for many hours.  Once mixed, you either use it or throw it away because it will harden.  Some are one part to one part (1:1) and some are two parts to one part (2:1).

Four in the list above are UV resins and I’ve marked them UV.  There’s only one bottle, no mixing involved and the resin stays wet until you cure it with a UV lamp for up to 20 minutes.  If you don’t want to buy a UV lamp, you could set your resin-covered pieces in the sun and protect them from bugs, dust and weather.

I thought about testing Pebeo Gedeo Crystal Resin, but I saw a cured sample in the local art supply store and it had pulled away from the edges a little.  

I also tried Loon Outdoors UV Clear Finish and their UV flashlight because I’d read a review by someone who’d used it on polymer clay and said it worked wonderfully.  It’s made for tying flies for fly fishing.  For me, it remained sticky.  I cured it for 20 minutes under the UV lamp and it turned yellow and was still sticky.

TESTING METHODS

I first made small, flat tiles from polymer clay.  I used a Cabezel mold to make another set of tiles with bezels.  After they were baked and cooled, I wiped them with rubbing alcohol to clean off any oils and labeled them with a Pilot pen.

Following the manufacturer’s instructions, I mixed and applied resin.  I tried to put the same amount on each flat tile and covered them all to the very edges.  I filled the bezels until they didn’t look like they could hold any more without running over.

After letting them sit for a few minutes, I removed the air bubbles by passing the flame of a BBQ lighter close to the surface.

Next, I cured the resin as directed by the manufacturers.  I used either the UV lamp or set it aside to cure for 24 hours, covered with little plastic tubs to keep out the dust.  Warmth helps resin to cure faster, but I just put the tiles on a shelf in the basement where it’s about 68-70˚F.  Resin doesn’t like humidity when curing.  That’s rarely a problem where I live.

Resin may need a few days to completely cure.  I put some test pieces in a plastic baggie prematurely and a couple tried to stick together.  The surface of the EnviroTex Lite was a tiny bit sticky, so maybe I didn’t get the parts exactly equal.

WHY RESIN?

Resin gives a hard, clear, glass-like finish.  There’s almost nothing like it for bringing out the shine in mica powder.  It can be wonderful, if you use the right brand for the right purpose.

It adheres like glue to surfaces and you can actually use it as a glue.  I’ve only used it on Premo, Pardo and Cernit, so I can’t say how well it adheres to other brands of polymer clay.  I’ve been able to pull it off of Pardo, but it wasn’t easy.

It can also be messy and frustrating.  It can spill out of your bezel.  It can sag and develop bare spots.  It can get bubbles and dust in it.  It can refuse to harden or it can harden in the bottle.  It can turn yellow if not mixed in the proper proportions, or if exposed to more heat than it’s designed to tolerate, or if exposed to the sun too long.  Some epoxy resins have UV stabilizers to prevent yellowing by the sun.

WHY EPOXY RESIN? 

Epoxy resin is good for a beginner, which I am.  It has very little odor, but you need to use it in a well-ventilated area and/or wear a respirator mask.  It isn’t as toxic as polyester or polyurethane resins.  It’s not rubbery like silicone resins.

ONE PART AND TWO-PART EPOXIES

There are one part and two part epoxies.  One part epoxies cure with UV light.  Two part epoxies cure from the heat caused by the chemical reaction caused from mixing the two parts together.

UV resins can also be called gel resins. I’ve read that gel resins tend to crack and aren’t as durable as two-part epoxy resins.

UV LAMP

I had a Loon UV flashlight, but it was small and didn’t seem practical for the 20 minute cure time that UltraDome needs, so I needed a 36 watt black light.

After shopping and comparing, I settled on the NailStar™ 36 Watt Professional UV Nail Dryer Nail Lamp.  I chose it because it had a “constant” setting on the timer, instead of just 2-3 minutes.  There are many other good lamps available.  Just be sure to get the type of light your resin requires.  For the brands I bought, I needed a black light rather than an LED light.

I really thought about buying a UV nail lamp that was large enough to put in two hands at once.  If I ever do larger resin pieces, it’s good to know it’s available.

THE RIGHT TOOL FOR THE RIGHT JOB

My main goal was to find a resin that wouldn’t pull back from the edges of a flat piece or create bare spots in the top of a curved piece.  I wasn’t really interested in doming or molding.

For jewelry, there are basically three types of resin:

1. doming resin
2. casting resin
3. those that try to do both

Doming resin is designed to contract into a rounded dome when poured into a bezel.  It has a high surface tension.  It can also be called coating resin.

Casting resin is designed to be poured into a silicone mold.  It has a low surface tension.

Those are simplified examples.  In general, a doming resin contracts more than a casting resin.  People use resin for many things besides bezels and molds.

For clear explanations of resins and fairly easy resin projects, including using resin with polymer clay, see The Art of Resin Jewelry by Sherri Haab.  For more unusual projects, see Susan Lenart Kazmer’s book Resin Alchemy: Innovative Techniques for Mixed-Media and Jewelry Artists.

It’s not always clear from the manufacturer’s descriptions what type of resin it is and what purpose it’s meant to serve.  I learned much from reading articles by Katherine Swift at ResinObsession.com.  I’d suggest her Resin Choices Chart and  What Are the Different Types of Resin? article.  If you join her email list, she’ll send you her free ebook “50 Tips to Help You Be Better with Resin.”

DOMING

The best doming resins were:

• Magic Glos
• Little Windows
• Cernit Kit
• Ice Resin
• EnviroTex Lite

Magic Glos made the best dome.

In my observation, a doming resin will contract until it reaches whatever thickness its chemical makeup dictates.  To cover a flat piece with a doming resin, you either need a very thick coat or multiple coats.

If you’re trying to cover a flat piece with a resin that really domes, it will pull away from the edges either immediately, or while it cures.  To prevent this, I tried sanding the surface of the polymer clay to give it some tooth, thinking the resin might stick better.  I tried varnishing the surface, thinking it was rejecting the polymer.  Neither made any difference.

FLAT SURFACES

The resins that didn’t pull back from the edges of a flat surface at all were:

• UltraDome
• Deep Shine, though I got bubbles in mine

Resin Obsession, Art Resin, Amazing Clear and EnviroTex Lite only pulled back a little. The rest pulled away from the edges much more.

Resin Obsession domed somewhat and it didn’t pull back from the edges.

Little Windows domed well, but pulled back from the edges a lot.

Art Resin domed and didn’t pull back from the edges.

I followed the directions for Deep Shine and used the brush that came with it.  I should have washed the brush first, because I got lots of lint in the resin.  I wiped the resin off and reapplied it thinly with a gloved finger.  The directions also say to not apply it thickly or it will get bubbles, so I guess I applied it too thickly because I got bubbles and the surface wasn’t smooth.  It is not a doming resin.  Strange thing is it made the clay curve up.

The bottle of Chinese resin I got was like thick glue and wouldn’t self-level, had lots of bubbles and remained sticky.  I put it under the UV light for longer and it started to turn orange.  I understand I got an old, bad bottle.  Some people really like this when it’s fresh.  It took three weeks to arrive from China, so I don’t really want to order another one.

MOLDS

I haven’t made any resin pieces from molds, but you’ll probably get a better result with a casting resin, such as Alumilite Amazing Clear Cast or EnviroTex Lite Pour-On.

You can make your own silicone molds from 2-part molding putty or you can buy silicone, polypropylene or polyethylene molds specifically made to use with resin.  Using a spray-on mold release product or olive oil prevents sticking.  Resin can stick to some plastic and rubber molds, so verify beforehand whether they’ll work with resin.  Flexible molds make it easier to pop out the cured resin than rigid ones.

BUBBLES

Some of the resins tested had bubbles.  The bubble-free resins were:

• UltraDome
• Ice Resin
• Amazing Clear Coat
• EnviroTex
• EnviroTex Lite
• Cernit Kit
• Magic Glos
• Resin Obsession

It’s a good practice to let resin rest for 10 to 20 minutes to allow bubbles to rise to the surface where you can pop them.

I’ve read that some brands are less prone to bubbles than others and the thicker the resin, the harder it is for it to release bubbles.  If resin is too thick, you can put its container into hot water bath to thin it.

Using a flame works and it’s satisfying to watch bubbles pop that you didn’t even see.  Don’t get too close with the flame because excessive heat can change the surface of the resin.  I’ve read it’s the carbon dioxide from the flame that bursts the bubbles, not the heat.  You can also wave a heat gun over it.  With the heat gun, maybe the heat makes the resin thinner so it releases the bubbles.

If you have surface bubbles or sags in cured epoxy resin, you can sand them out and apply another coat to restore the shine.  Another coat forgives a lot of mistakes.  Buffing lightly can give a satin finish, but I haven’t found it to bring back the extreme shine.  It can make whitish areas, if you overdo it.

I understand that polyester resin doesn’t get bubbles and you can buff it to a high shine, but there’s the smell and toxicity to deal with.

COLORLESS?

The most colorless resins were:

• Ice Resin
• Art Resin
• Resin Obsession
• Little Windows
• UltraDome
• Deep Shine
• Magic Glos

The rest had just a tiny bit of a greenish or amber cast.  The thicker the resin, the more obvious these color casts become.

YELLOWING

This YouTube video shows several brands of resin and how they yellow over time when exposed to UV light.

SMELL, TOXICITY & CLEANUP

It’s very important to read all the instructions that come with resin.  Some brands have more complete instructions and material safety data sheets (MSCS) than others.

After reading about the allergic reactions people have had to resin, I protect myself.  None of the resins I used were polyester, polyurethane or silicone, so they didn’t have much of a smell.  That doesn’t mean they’re not harmful.  Some of the warnings say to not inhale the resin or recommend using it in a well-ventilated room.   None of the brands I used recommend using a mask, but I wear one.  Make sure your mask is made for vapors or fumes, not just for particles.

Wear nitrile gloves, not latex.  Latex can have a reaction with resin or allow resin to penetrate to your skin.   Some people are also allergic to latex.  Don’t get resin on your skin or in your eyes.  You can clean up your work surfaces with alcohol or baby wipes, but if you get it on your skin, use soap and water.

Once resin is cured, it’s hard to remove, so do a thorough job cleaning up.  You can try an Xacto knife, razor scraper, sandpaper or acetone (fingernail polish remover) to remove dried resin.

CONCLUSION

UltraDome is the best UV resin for good, flat coverage to the edges without bubbles.  It works well to cover curved surfaces and give a fairly thin coat to flat pieces.  My second choices for this would be Alumilite Amazing Clear Cast, EnviroTex Lite or Resin Obsession.

Lisa Pavelka’s Magic Glos made the highest dome.  Don’t expect a thin layer of it to cover a flat surface because it will pull back a lot.  A really thick layer or multiple coats might remedy this.  Ice Resin, Cernit Kit Finish Glass and EnviroTex Jewelry Resin also made nice domes.

Ice Resin, Art Resin, Resin Obsession, Little Windows, UltraDome, Deep Shine and Magic Glos were colorless.  The other resins tested had a slight green or amber tint.

If I had to pick one UV resin, it would be Ultradome.  If I had to pick one two-part resin it would be Amazing Clear or maybe Resin Obsession.

WHERE TO GET SUPPLIES

Most of the resins I tested are commonly available through art and craft stores or online. I believe online is the only way to buy UltraDome at UltraDome.com or EpoxyJewelry.com.

Cernit Kit Finish Glass is a new product and currently seems to be available only in Europe.  I ordered mine from PerlesandCo.com and it arrived promptly.

I bought my UV nail lamp through Amazon.com

COVERING BEADS WITH RESIN

Curing an even coat of resin on round beads and cabochons is more involved than just using the right resin.  If you’d like to learn how I do it, I have a  Faux Moonstone tutorial that explains my methods in detail.

 

 

 

 

UPDATE 12-21-2018: I checked on the resin samples nineteen months after the original test.  They’d been sitting in a closed box in my windowless basement with very little exposure to light.  The EnviroTex and EnviroTex Lite have both yellowed .  EnviroTex Lite more than EnviroTex.  The rest of the brands look about the same.