Polymer Clay in the Dishwasher

Can you put polymer clay in the dishwasher? Does it need to be sealed? More at The Blue Bottle Tree.I started the testing for this article  intending to review Mod Podge Dishwasher Safe Sealer. But I figured since I was running the tests, I might as well try various clays and various sealers, too. So this really turned out to be more comprehensive than just a review of a single product. I suppose this has become an article about polymer clay in the dishwasher.

It’s really fun to decorate and cover glasses and utensils with polymer clay. So the question of durability always comes up. Most people do recommend hand washing any hand-decorated glasses and cutlery. But is that necessary? What actually happens when you put polymer clay in the dishwasher? Does it crumble? Does it peel and flake off? Does it turn white and disgusting? And does a sealer make polymer clay more durable? Well, thanks to the patience of my family over the past three months, and thanks to my dishwasher, we now have a pretty good idea. And honestly, it’s not what I expected.

Testing sealers and polymer clay in the dishwasher. More at The Blue Bottle Tree.
All baked and sealed, ready to be tested for durability in the dishwasher.

Skip to the Fun Results!

Test Conditions

The Votives

I used three straight sided glass votives. Each was covered with a thick sheet of polymer clay, leaving the top third of the votive bare glass. Black clay was used so that any deterioration of the sealer would be more visible. I used Fimo Professional, Premo, and Kato Polyclay. The clay was just smoothed onto the glass, no adhesive was used. I used a smooth sheet of copy paper to “texture” each votive so they would all have the same surface texture. All three votives were baked for an hour at their respective correct temperatures and then washed with rubbing alcohol to allow for optimal sealer adhesion.

These are the brands I used to test polymer clay in the dishwasher. Read more at The Blue Bottle Tree.

The Sealers

The votives were marked into five separate sections, each received a different sealer, and one left bare as a control. The sealers used were Mod Podge Dishwasher Safe Gloss, Varathane, Liquitex Gloss Varnish, and Future. Three coats of each sealer were used and they were left to dry for 28 days, according the directions on the label of the Mod Podge. The sealers were used on the polymer clay and also on the area of glass directly above it. This was done to check if sealing the interface between clay and glass was necessary. I labelled everything with a Sharpie.

Sealers tested on polymer clay in the dishwasher.

The Dishwashing

Each votive was placed over tines in the top rack of my dishwasher and just left there for three months. I have a typical GE dishwasher, nothing fancy, and it was always used with the potscrubber option enabled. Heated drying was not used. We used Finish dishwasher tablets for each load. My family was crazy busy this spring and we ate frozen meals or ate out a lot, so we didn’t run the dishwasher every day. I estimate that it went through about 60 cycles in the three months. And yes, my husband did ask, several times, how much longer we’d have polymer clay in the dishwasher!

Votives I used to test sealers and polymer clay in the dishwasher. More on The Blue Bottle Tree.
After three months in the dishwasher, these votives look a bit worse for wear. Interestingly, the clay is fine. It was only the sealers that were a bit of a mess.

Polymer Clay in the Dishwasher

After three months of being in the dishwasher, the unsealed area of all three brands of polymer clay showed absolutely no wear. There was a slight film of some kind, which felt sort of waxy, but that was easily removed by buffing with a towel. I’m thinking this residue was something like soap scum. But all three brands of polymer clay had no crumbling, chipping, degrading, cracking, or obvious discoloration. Since I used black clay, I can’t tell if light colors would be discolored or not. Perhaps that’s an experiment for another day.

Sealers on Polymer Clay in the Dishwasher

Whereas the polymer clay looked pretty good after being in the dishwasher for three months, I can’t say the same thing for the sealers. They did not fare so well. Here are my observations.

Mod Podge Dishwasher Safe Gloss

This sealer is marketed for glueing and sealing paper decoupage onto glass and ceramic plates and mugs. It’s also nice when mixed with glitter and applied to a mug. But I wondered if it would also be a good sealer for polymer clay and if it would be good to protect mica powder and paints on polymer clay in the dishwasher. Sadly, however, this sealer is very streaky and leaves very obvious and visible brush strokes. It does not level out and most certainly is not invisible on glass. Mod Podge Dishwasher Safe became sticky on Fimo Professional after one wash, though, it did bond well and can’t be scraped with a fingernail. But on Fimo the finish developed tiny white spots over time. Mod Podge Dishwasher Safe fared a bit better on the other two brands of polymer clay in the dishwasher. Although it didn’t discolor on Premo or Kato, it can be scraped off with a fingernail if you really dig at it.

Mod Podge Dishwasher Safe Gloss stayed attached to the glass very well, however. Of the three votives, only one showed a small area of cracking.

Mod Podge Dishwasher Safe Gloss leaves very obvious brush strokes on both glass and polymer clay.
Here you can see the very obvious brush strokes of Mod Podge Dishwasher Safe Gloss. I wouldn’t call this very glossy, either.

Varathane

It’s no secret that I really like the way Varathane performs in a variety of situations and on a variety of clays. This , I now know, includes polymer clay in the dishwasher. I didn’t like the way any of these sealers performed, but the Varathane performed better than the others. The gloss finish of the Varathane remained glossy on Premo, but dulled considerably on Kato. On Fimo Professional, however, there were many tiny white spots. I’d think that Premo with Varathane would be the magic solution, but sadly, the Varathane can be easily scraped with a fingernail. Varathane was not easily scratched on Fimo Professional and Kato.

Varathane was remarkably clear on the glass, and I wouldn’t hesitate using it for sealing paper decoupage on glass. But not in the dishwasher. The coating of Varathane that was on the glass lifted off with the first wash and crumpled like a wet sack onto the polymer clay section of the votive, where it remained for the rest of the three months of testing.

Varathane on on glass in the dishwasher peels right off.
Both Varathane and Liquitex Varnish looked great on glass until the first run through the dishwasher. They both sloughed off the glass in a sheet.

Liquitex Gloss Varnish

Well, this sealer was a total failure across the board. On all three clays it became rubbery and tacky, similar to a latex balloon. On Fimo, it also developed tiny white spots. On Kato Polyclay, when I applied the Liquitex Varnish, it beaded up and even with three coats I couldn’t get a smooth finish. This varnish also sloughed off the glass part of the votive with the first wash.

Future

Future is the old name for very clear acrylic finish that is used on no-wax floors (ie. vinyl floors). It has changed names and labels many times as the product as been bought by new corporations. You can (I think) now find this product under the name Pledge Floor Care. I have an old bottle that I’ve had for 10 years. But I believe it’s the same stuff. It’s a favorite of polymer clayers for its low cost, ease of application, and good shine. Durability, however, is its downfall.

That point was made very clear in this test. Very early in the three months of testing, this finish deteriorated and turned white and chalky on all three brands of polymer clay tested. Future is most certainly not a suitable sealer for polymer clay in the dishwasher.

Future floor polish is not a good sealer on polymer clay in the dishwasher. It turns white.
Future (aka Pledge Floor Care) turns white after being in the dishwasher just a few cycles.

Conclusion

I ran this test in hopes of identifying a good sealer to use to protect polymer clay in the dishwasher. I found that in all cases, the sealers deteriorated faster than the polymer clay. If you are going to cover glass or utensils with polymer clay and run them through the dishwasher, don’t seal them. From the limited time test that I ran in this article, the polymer clay holds up quite well to dishwasher cleaning and yet an occasional run through the machine isn’t going to hurt anything.

Here are some other points:

  • Mod Podge Dishwasher Safe Gloss is durable in the dishwasher but doesn’t give a very nice glossy finish. Lots of brush strokes.
  • Varathane gives a better overall finish that than the other sealers I tested, especially on Premo. But It could be scratched with a fingernail.
  • Liquitex Gloss Varnish is not suitable on polymer clay in the dishwasher.
  • Future (aka Pledge Floor Care) is not suitable on polymer clay in the dishwasher and turns white rapidly.
  • Bare polymer clay holds up in the dishwasher far better than any of the sealers I used on the clay.
  • Don’t use a sealer on polymer clay unless you have to. And if you do, don’t put it in the dishwasher.
  • If you do need to seal polymer clay used on dinnerware, like if you are using mica powders that need to be sealed, don’t put them in the dishwasher! Hand wash them only.
  • Sharpie didn’t hold up on the glass in dishwasher. It washed off after 2-3 cycles.
  • Durability of polymer clay in the washing machine had similar results.
  • Note that each clay behaved differently with the sealers. This might explain why so many people report varying results with paints, sealers, and other chemicals on polymer clay. Maybe they’re using different brands of clay.

In summary, polymer clay appears to be fairly durable in the dishwasher, at least for the short term, and does not need to be sealed. In fact, the sealers don’t hold up at all. For maximal life, I still recommend that you hand wash any polymer clay covered dinnerware. But there’s no need to fear putting unsealed, sturdily built polymer clay in the dishwasher occasionally.

50 thoughts on “Polymer Clay in the Dishwasher”

  1. Thank you so much for this.
    Great research and much appreciated. I will be forwarding this onto a lady I know that does knife and cake slice handles.
    Thank you

  2. I bake varathane or polyacrylic onto the polymer clay (Premo) flatware handles I make. My suggested care is to hand wash the items, but it is good to know that they can handle an occasional trip through the dishwasher. Thanks for doing this testing.

    1. Unsealed clay can. Not sealed. Maybe one or two trips would work on Premo, but certainly not on Fimo. Sealer degrades far too easily in the dishwasher.

  3. Thanks Ginger !!!! I bet if you wiped the future area with ammonia the Future would come all the way off easily.

  4. Thank you for the testing, it was very interesting. Your last statement reminded me of some beads I made about 10 years ago and sewed them around the neckline of a T-shirt. I still wear that T-shirt and it has been washed and dried several hundred times. No coating on the beads and the beads look way better than the T-shirt.

    1. I have found exactly the same thing with buttons I’ve sewn on clothes I made the kids. Also, I did a test on washing polymer buttons…I just ran it through the wash a few dozen times, and it help up just fine.

  5. Ginger, thank you so much for all the work you put into this. You spent a lot time on this one, we truly appreciate all that you do! Great stuff!

  6. I have been putting my rice paddle in the DW for years. The clay is fine…unless you are a doof and put it on the bottom shelf by the heating element. 🙁 But if you leave it on the top shelf…polymer clay will last for years with no problem. And no sealer. 🙂

  7. Debbie Goodrow

    Thank you for your testing, and clear reporting. I turn to The Blue Bottle Tree often for my information!

  8. Merci beaucoup pour le test, J’évite d’utiliser les vernis et préfère le ponçage/polissage, mais maintenant je sais ce que je pourrai donner comme info au cas où 😉

  9. Flo :::Talismans

    Thank you Irish for this very good test. People often ask me about flatware for children that I realise : now I can answer with full knowledge of the facts and shall say that a great lady of polymer clay made a very elaborate test !

  10. i didn’t think one could use polymer clay on dishware that comes in contact with food , so what am I not understanding when you talk about “hand wash any polymer clay covered dinnerware.” where is the clay added to the dinnerware

    1. Actually, yes, you can. But not in food-contact areas. So you can cover the outside of a glass or the handles of cutlery. For more information on the specifics of the food-safety issue, check out my article “Is Polymer Clay Safe?”

  11. Hi ginger, If you want a sharpie that will hold up to water and washing then buy the Industrial Sharpie (it has red letters on the barrel). Used in hospitals and other environments where marks absolutely must stay on even when subjected to steam and water it’s a VERY permanent marker. Office supplies sell them in 2 packs.

  12. I am liking your (skip to the fun results) bullet points and straight to the point for people like me!

    1. It was actually some of our conversations that made me realize that I needed to add that feature. Some of us are detail people who are happy with diving into long articles, but I think a lot of us (especially when on a phone) have our eyes glaze over with too much information. Giving people the option to go either way seems to make sense.

  13. How many coats of each did you use, and did you sand the polymer before applying? It sounds like the Varathane held up okay on the polymer itself, just not on the glass, which isn’t usually covered by a varnish. I usually recommend to my customers that they hand wash any utencils or glasses that have polymer on them, just to be on the safe side.

    1. Since the votives were straight sided, I just rolled them on plain copy paper to give them a uniform texture. Not smooth, but not rough either. And I put three coats of each sealer on. Yes, the Varathane held up better than either Liquitex or Future. But it was far from being “okay”. All of the finishes had fine white spots on Fimo Professional and looked terrible, including Varathane. The Varathane on the Premo stayed the shiniest, but still looked pretty rough where it scratched. I can still easily scratch it off. Sealers/varnishes just don’t hold up as well as bare clay.

  14. Thank you so much for sharing your experiments, I’ve been wondering how polymer clay cup decoration or covering utensil handles would survive wasking. Perhaps sealing with Fimo deko gel could work better than other sealers, I never tested it on dishwasher but I know it works as a wonderful sealer for objects that will be used harshly, and well, it’s clay ^^

  15. Thanks Ginger, great article. Polymer cracks when you use heat in your dishwasher. I told the kids not to put my covered wooden spoon in there, but in one ear and out the other, lol. It cracked all over.

    1. I would think that would have more to do with the swelling of the wood in the water than the heat. Your kids listen like my kids. Sorry about your spoon. Ugh.

  16. I agree that you shouldn’t use a sealer unless you have to! Jacquard makes a Pearl Ex Varnish that can be heat set. That may need to be dishwasher tested (have never owned a dishwasher, so I can’t do the test! LOL)

  17. Cara Jane Hayman

    Very thoughtful and thorough testing as always! Thank you so much for sharing your results. I made a polymer decorated spoon for a friend a while back and the answer is white clay stains in the dishwasher – it’s now a pink and purple pattern instead of purple and white.

  18. thanks for sparing us all that testing. so, did you need to buy a new dishwasher after all this testing? i’d be worried that deteriorating plastic would total ruin the dishwasher – even if it had a disposal feature. please mention that this testing is probably not safe for septic systems.

    1. Oh goodness, there wasn’t THAT much deteriorating plastic. Just a couple of flakes of sealer that came off of the glass with the first wash. I knew to look for it, so there was no harm. I’m on city sewer here, but honestly there’s no reason why this would hurt a septic system. Now if I were doing industrial production, maybe! Though I will have to admit that a new dishwasher does sound nice. I want one of those stainless steel jobs with the super quiet super blasting features. Think I could convince my husband? 🙂

  19. Lol you beat me to the test 🙂 I just bought a dishwasher 🙂 nothing fancy it does the job I want anyway 🙂 and I was going to run some tests to see how it went but I was going to spray my test pieces with PYM II as that turns paper water proof 🙂 same with photos and I have been using this on all my prices that have mica powder on them to ensure they are sealed 🙂

    Maybe as you have not used that for the test I will still run my own tests but I only use Kato and now Sculpey Premo as I love their colours 🙂 so my test will only reflect these two brands 🙂 but I will be using the colours as well as the black only because I wanted to make sure of which ones I could use or not for a special wedding gift I am making for a friend 🙂 once I have run my tests on my sample gift first 🙂 wanted to make sure it did not matter if they were plain or mixed colours as they are used in the project 🙂

    At least I know I am not the right track though thank you so much for your feedback on your tests 🙂 at least I now know not to varnish after I have sprayed them with the PYM II 🙂
    Have a great day Ginger 🙂 and ta 🙂

  20. Great blog post. I’ve been running similar sealant tests on metal clay and am concluding that I prefer the bare metal. Have yet to find a sealant that really REALLY stands up to long-term wear. That may be fine for a froo-froo piece of jewelry that someone wears once a year, but I want to make jewelry you can put on and leave alone for months on end (yes, I’m that lazy about wearing jewelry).

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  22. Ginger, thank you so much for your test and for reinforcing my decision to not use a sealer on my utensil handles. In the past, I have had a few friends say that the clay cracked when they put it in the dishwasher, but found out that they were using the high heat drying cycle and the utensils were on the bottom shelf utensil rack. I agree with you that hand washing is still the best method of care, but the dishwasher with the no-heat dry cycle is ok, too.

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  24. I have a couple of small expresso cups I want to decorate with polymer clay. I was wondering if u can seal them with resin and then they are dishwasher safe or will the resin chip off?

    1. Resin will not bond well to polymer clay. It just lies on top of the clay. Water will get forced under the resin and it will lift. Just decorate with polymer clay only…no sealing is needed. All varnishes and sealers will degrade in the dishwasher. Polymer clay will withstand it, but it might discolor over time. Plus, the polymer may lose bonding with the ceramic if washed in the dishwasher. Hand washing should be just fine however.

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