We all have our favorite shampoo and conditioner. We have pretty strong opinions about the best brand of mayonnaise (or we hate it entirely). So it should really come as no surprise that I very much have picked a favorite polymer clay sealer, Varathane. I don’t always use a sealer or varnish on my polymer clay, but when I do, Varathane is my favorite.
Do You Need to Seal Polymer Clay?
One of the most common questions I am asked is, “Do you need to seal polymer clay?” The short answer is no. Baked polymer clay is a durable plastic and as such does not need to be sealed against the elements. Polymer clay is so durable that it will hold up to wear, weathering, washing, and use better than any sealer that you can put on it.
But the long answer is that sometimes you do need to seal it. If you use mica powders such as Pearl-Ex or Perfect Pearls, although perfectly durable on a sculpture, when used in jewelry or against the skin you’ll want to seal the powder to keep it from rubbing off. The same goes for powders such as metal pulvers or chalk pastels. Some techniques, such as a variety of crackle techniques, use metal leaf adhered to the surface of the polymer clay, and that does need to be sealed. Most acrylic paint is going to be as durable as your sealer so you don’t always need to seal it when used to paint the surface of polymer clay. But using a sealer can add an extra layer of durability.
You would also want to use a sealer on polymer clay when you want to change the look of the surface. If you want the surface to be more glossy or more matte then a sealer is a great way to do that. And adding even a thin layer of a sealer can intensify colors just like when you find a pebble at the beach then get it wet to see the colors. By the same token, it makes translucent clay more translucent, mica powders more sparkly, and colors much more rich and deep.
What is Varathane?
Varathane is a brand name of polyurethane varnish that’s been around since 1958. It’s used as a wood, furniture, cabinet, and floor finish. Chances are good that there is wood in your home that is finished with polyurethane. It’s been a favorite of polymer clay artists for over 20 years because it just works. It’s currently produced by the Rustoleum Corporation, but previously it was made by a company called Flecto. You might even see it referred to as Flecto from time to time. It’s the same stuff. It’s also undergone many label changes over the years and the can you’ve been using, or the label you see advertised online, might differ from what you currently see. Anita Brandon of Melody O’Beau Designs made phone calls and talked to the manufacturer, verifying that this current label is in fact the same product we’ve all been using over the years.
Varathane does come in an oil based and a water based version. For polymer clay use, you will have much better results if you use the water-based version. If you need to use soap and water to clean up, that’s the right one. You don’t want the one that requires use of paint thinner or mineral spirits to clean it up. Oil-based Varathane can work on polymer clay, but it takes a long time to dry (days) and gives a yellow cast.
Varathane comes in half pint, quart, and gallon cans. It also comes in a spray. I’ve heard that some people have had success with it, but I find that it gives a rough and uneven spray finish. Sprays are always tricky, most of them aren’t polymer clay safe, so stick with the liquid in the can.
Characteristics of Varathane
Varathane is a milky white liquid with a slight bluish tint. It is slightly thicker than water, but not gloopy like many other varnishes that I’ve tried. It has a very mild smell, not a whole lot different from lots of craft paints. It goes on easily with a brush and dries absolutely clear within minutes. You can recoat it again as soon as the first coat dries. But I do like to wait an hour between coats. (Okay, I admit it, sometimes I rush drying a coat by using the heat gun. I’m so impatient.)
You can use a brush, sponge, or even your fingers to apply it. Don’t “scrub” back and forth with the brush, though, or you will get bubbles. Anita’s article on Varathane goes in detail about how she gets a perfectly speck-free finish on her wonderfully fun polymer clay cherries. If you dip coat your beads, give them a quick spin to remove excess Varathane before putting them up to dry. It’s better to use several thin coats than one thick one. I use a very thin coat if all I’m doing is setting mica powder. But I use several coats to build up a thicker layer if I’m going for a glossy, glass-like finish. And yes, you can thin your Varathane with a bit of water to get an even thinner coat. This is sometimes the best way to get a smooth, low shine finish, too.
To keep your can of Varathane clean, don’t apply it directly from the can. Decant a small amount into a small bottle, and apply it from there. Prescription medicine bottles work particularly well for this. I also like to use these nifty containers I found at WalMart, too. I like the wide mouth, perfect for dipping beads.
Varathane comes in gloss, semi-gloss, and satin finishes. I see that Menards carries a matte finish as well, but I’ve never tried it. I see very little difference between the gloss and satin, though, especially when used as a thin sealer coat. I think if you built up several layers you’d see that satin is less glossy than gloss. But it’s not matte by any means. I wouldn’t spend the money for the satin, by the way. I’d just use a thin coat of the gloss version if I didn’t want a very shiny finish. Maybe I can find some of the matte finish soon, and I’ll let you know how it does.
How Durable is Varathane on Polymer Clay?
First let me say that I always use Varathane on polymer clay that isn’t waxy or oily. If you’re using Pardo or Kato Polyclay, give the clay a good wipe with alcohol before applying any sealer. (Even then, I do have trouble with any sealer sticking to Kato very well. It tends to peel off like skin after a sunburn.) Varathane will dry to the touch right away, but can take weeks to fully cure. To accellerate that curing process, I usually put sealed items back in the oven for another bake. I have often seen it recommended to use 200°F (93°C) for 10-15 minutes, but that seems to be info that’s “passed down” and I don’t know its source. I usually just bake it again at my clay’s favorite temperature. (Usually with the next batch of beads.)
Once cured, Varathane is water resistant and will easily hold up to washing. The surface is hard enough and durable enough that scratching with your fingernail will not tear through it (once fully cured). Yes, of course, you can scrape it with a knife or something, but don’t do that! Varathane will never fully cure to a rock hard finish on polymer clay because it is softened by the plasticizer in polymer clay. But it is hard and durable enough for jewelry use.
If you ever need to remove Varathane, you can dissolve it with rubbing alcohol. Not that I’ve ever had to soak dried Varathane off a brush or anything. 😉 Okay, I admit it. I’m always forgetting to wash my brush. Sometimes it’s hard to completely remove dried Varathane from polymer clay. It’s really very durable. But alcohol’s fairly safe and fairly effective at removing it, especially before it’s fully cured.
Is Varathane a Sticky Sealer?
There seems to be a fear out there about sticky sealers. And for good reason. If you use nail polish as a sealer or glaze, your project will usually turn sticky with time. If you use the wrong spray sealer, it can get sticky over time. And some acrylic varnishes, such as the green label Liquitex Gloss Medium and Varnish, seem to never fully dry and stay sticky. But I’ve NEVER, NEVER, EVER had Varathane remain or turn sticky. In fact, the feel of dried Varathane is sort of like a smooth plastic. I really, really like it. (How’s that for a scientific term?)
Is Varathane Non-Toxic?
Even though Varathane is designed to be a wood varnish that’s commonly used on furniture and floors, that doesn’t mean that it’s a toxic substance. Yes, I know, it’s easy to think of the stinky cans of paint that you’ve used in the past. Well, this isn’t that. Totally different stuff!
If you’ll look at the label of many craft items, such as polymer clay itself, you’ll see that there is a seal that certifies the material is tested to be safe and non-toxic as a craft material. To get that certification, a manufacturer has to have the material tested. Since Varathane is a wood varnish and everyone expects a product used in that capacity to be possibly toxic, there’s no reason to pay to test and get certification for it to labelled as non-toxic. That being said, it is a fairly non-noxious substance as paints go. It is not turpentine or paint thinner based. It is water based and doesn’t have volatile compounds such as any of the aromatic hydrocarbons like benzene and toluene.
The label does warn to keep it out of your eyes and use good ventilation while drying. The only compound the label lists as being worrisome (glycol ethers) are also in sunscreens, and totally evaporate during drying. Don’t drink it. But I wouldn’t hesitate using it to seal jewelry. Dried Varathane is non-toxic and perfectly fine for skin contact. UPDATE: Safety rules changed in 2015, and many varnishes contain N-Methyl-2-pyrrolidone (NMP) as a solvent, in addition to water. This is a fairly low toxicity solvent, but it has been shown in some tests to cause reproductive harm in high concentrations. Wear gloves and be sure to wash your hands if you’re pregnant. The solvent evaporates, so fully dried varnish (as with finished jewelry) has no safety concerns.
Availability of Varathane
In the US and Canada, Varathane can be found in many hardware stores and paint stores. Again, make sure you get the water-based variety that matches the label you see above. I’ve heard that some people have found it at Home Depot and Menards. I couldn’t find it here in my town so I ordered it online. But shop around, you’ll find it. You can also purchase re-bottled Varathane in small bottles from Polymer Clay Express.
Lately here in the US, all I can find in the hardware stores is Minwax Polycrylic. It’s not the same thing as Varathane. It WILL work as a polymer clay varnish. But it’s going to be subtly different from Varathane. As they say, your mileage may vary.
Varathane is available in North American and also in the UK from Amazon.co.uk. But if your country doesn’t have Varathane, see if you can find a water based polyurethane wood finish. Chances are that it will be very similar. The key thing to look for are the terms “water-based” or “water clean-up” and “polyurethane”. If you know of a another good polyurethane brand, please let me know!
- Craftmill, a UK craft supplier repackages a UK brand of polyurethane in smaller bottles. They say that it’s good for polymer clay. Might be worth a try.
- María Eva Ramos of Niná Studio tells me that she has used VITRIO water based polyurethane wood floor finish for several years and has the same good luck that I’ve had with Varathane. She’s in Venezuela, though, but it might give you a brand name to look for in addition to Varathane. Thanks María Eva!
- And Nicola Sutherland says that in Australia she uses Cabothane with great results.
- In Latvia, Tin Liva has been using this polyurethane for 7 years and reports that it’s just like Varthane (which she has also used). Look for Synteko Pro – one-component polyurethane water based wood floor finish;
Synteko Pro 90 (gloss), Synteko Pro 20 (matte), Synteko Pro 45 – (satin
comes in cans 1l, 5l, 10l
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