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Best Heat Resistant Sealing Finishes for Tiles and Coasters

Another trip to scour the local stores this time to find more possible options for how to get a nice glossy seal on painted tiles that will stand up to the heat of a hot coffee mug.

Video comparison and test of various clear spray finishes to use over the top of acrylic painted ceramic tiles.

My local car part supplier yielded three possible spray finishes to try on my tiles. I am trying to find the perfect finish for the painted tiles that will turn them into functional coasters. My criteria – economical (rules out resin), ideally available on the island so it’s easy to get my hands on, glossy finish, easy to use, stands up to the heat of a hot coffee mug without going sticky.

On trial this week:
Kamar Varnish by Krylon
Duplicolor Clearcoat Acrylic Enamel – (can looks different but DA1692 is the clear gloss, I checked with Duplicolor)
Duplicolor Gloss Clear Engine Enamel

Here are some earlier trials and tests of other varnishes and products that you might like to check out:

In this test, I used 3 previously painted ceramic tiles which had been left to fully cure for 1 month. I followed the instructions on the cans for how to use the paint – basically 2 light coats and then one wetter coat to finish. All tiles were then left for 7 days before carrying out the hot mug test. How did they get on – watch the video to find out!

So there we have it. After a lot of trials and errors and testing, I have found a product that seems to work for using a painted tile as a coaster. It works well with hot and cold drinks, water and hot coffee mugs. Nothing sticks, no water marks. All is well. I will still want to test some more to try to get the right thickness of spray to get the best possible gloss finish while minimizing the look of the spray particles. But if you want to protect your painted tiles, this is the product that I recommend from all those I have tested so far:

Dupli-Color EDA169307 Premium Enamel Spray

premium enamel spray

Click for Price

47 thoughts on “Best Heat Resistant Sealing Finishes for Tiles and Coasters”

    1. Hi, great demo, tks

      I am looking for a varnish that is safe for food related objects. Eg a spoon rest that is on the stovetop. Do you have any recommendations. Thanks so such, Karen

    1. I’ve tried searching for it in the UK too and the few places I could even see it listed were sold out. Might I suggest you try the Halfords own version and see how you get on. Several thin coats then leave it a week and give it a test. Worth trying…

    2. some of the engine enamel products available on Amazon.co.uk say that it should be baked after it has dried to fully cure the finish. I wonder if that might be what was needed for the engine enamel (last one) that didn’t quite make the cup test?

  1. Hello my question is which product would be the best for a trivet used for hot pan up too four hundred degrees.

    Thank you

    1. I don’t think any product would work well enough for this sort of heat. The heat would likely penetrate through to the acrylic paint underneath and I think could damage it, cause it to bubble or come away from the surface. I can’t be sure, I’ve never tried, but I’m not aware of anything I would trust to this sort of temperature.

  2. Mary Lou Arnold

    Hi Deby,

    I’m curious, does the engine gloss state that it needs to be cured in a warm oven? Thank you for this video – very helpful!

    1. Not the one that I have, but I’ve read that of some of the other brands. It’s not something I would recommend because of the potential fumes in your home, and I’m no expert on that. Some people have a separate mini toaster oven and use it outside for crafts though.

    2. ah, just saw your reply to this one; same comment as mine that I have just made. I am not sure whether they would emit any fumes, I have used ceramic glazes that needed baking, and these didn’t emit any fumes.

    3. I read a comment on another site and they said curing it in the oven sent it yellw

  3. I have used the enamel clearcoat. After 10 days it still smells. Do you know how I can get rid of the smell?
    Thank you!
    – it works perfectly with hot mug! Yaaay!-

    1. Hmm, well good news first that you have passed the hot mug test. About the smell though, not sure what to advise on that. I didn’t notice any smell but I’m not particularly sensitive to smells anyway. Maybe try wshing it in soapy water, but after that it might just be a case of waiting.

  4. Regarding the coasters, I use the Duplicolor engine enamel gloss clear. Three coats 24 hours apart then 24 hours later I bake them at 200 deg. Fahrenheit for 20 minutes and let them cool in the oven. My toaster oven is outside on the screened in porch. There is an odor.
    I’m going to try spray the three coats within the hour and bake 24 hours later.

  5. Is the Duplicolor scratch resistant? I’ve tried another engine enamel and it let my tiles get scratched.

    1. I’ve not used it long enough to be able to say. So far the ones I’ve done have been fine.

  6. Thanks so much for doing these tests deby. So just to confirm, if I buy the engine product that worked, I do not have to bake it. Right? I can’t bake anything as I don’t want to harm my kittens.

    1. I didn’t bake it, I wouldn’t in case of any fumes. However I have to say that others have since tested this product and some people say it still sticks for them unless they bake it. For the products that failed for me, some people say those products work perfectly for them and don’t stick. So unless you are using resin, there so far doesn’t seem to be any single product that has worked for everyone.

  7. Perhaps try a light sanding in between coats of the varnish. It’s something you would do when coating wood and I’ve done it with my alcohol ink pours. It would be something to test out to see if it makes a difference with the artifacts being left behind.

  8. Have you tried coating tiles with the poiycrylic then spraying with the engine enamel? I really would like to make trivets for hot items right out of the oven. Love your videos

    1. Hi Christina, we haven’t tried that yet. I think a similar topic has been discussed in our Facebook Group, which you can find and join here if you aren’t already a member!

    1. We’ve tried Krylon Kamar Varnish Spray and Liquitex High Gloss Varnish, and both turned out great! Just keep in mind that the reaction to the inks varies depending on the surface you’re working with (ie. glass) so it’s best to do a test run on a small batch to see if doesn’t burn the alcohol out.

  9. If you really want to bake them you could use a grill. We did this when melting beads for ornaments and it worked great. Ty for your research 🙂

  10. Interesting, as an artist looking for fast dry clear varnish that sets up durable. Like hit by vehicle tire durable, but it must not yellow, hopefully not. Dupi color is great for acylic paint but I’m not sure about 2x rustoleum. Krylon yellowed on my acylic paint right away & it brought underneath stains to the surface. I give this stuff a try, but some tyoe brush on varnish may hold better.

    1. Go to NAPA auto…..they have the same product in glossy finish. I just got some today and will try it out on my tiles (not ceramic) tomorrow. Engine enamel must be baked and will withstand temps of 500 degrees…..I was warned that the fumes are really dangerous…..good for engines as they get very hot and that is what cures and sets them . Also looking for something for trivets…apparently general paint makes something for wood A B clear or something like that…green can….not really expensive as it is ready to go out of the can….read comments on woodworking site person has taken hot off the stove onto his trivets (wood) and after 2 years they are still going strong….Will be looking for this in a small can to give it a try. I have been spraying with the Krylon clear before using the epoxy or whatever….on 2 tiles I forgot to “Krylon” I noticed on one the white appeared to yellow…but not the other….I used a different brand of white on the yellowed one but they looked the same before the epoxy treatment….they both dried for 4 days min and looked the same….when seperate you do not see a difference…also I have given a single spray of kryon to the base of whatever I am painting on…Often i spray paint different colours on my tiles and leave them for a week to dry and cure…spray with krylon non yellowing clear….and then paint away….I can have lots of tiles ready to go all at once!
      (i can also have some unique background colours too!)

  11. What was the temperature of the water you placed in the mugs and how much? Did you heat water in microwave and then pour into cups? How long did you leave them on the tiles?

  12. I am looking for a sealant for garden art that will be in the hot Florida sun and rain. Will the sealant stay firm and not get soft to pick up dirt particles? Thank you for all your help. Susan Mork

    1. We haven’t tested one that stays outside so I’m not sure how it will deal with the constant sun. But I would try out the Dupli Color Enamel spray and see if it works since it did well with heat in our test

  13. I applied 3 coats as per instructions. Wrapped them all nicely and gave them out at a baby shower. Got a call two days later saying they were sticking on cup. Anymore recent testing done by anyone?

  14. Is Resin the way to go if I am wanting to coat coasters that I have acrylic painted and then plan to sell? I have tried spray varnish and polyurethane gloss. And so far everything sticks to a warm mug. I’m willing to spend the money to resin coat them if this is what is needed in order for them to not stick to a warm mug.
    Any resin you recommend?
    Thanks so much for your research. I’ve been struggling with this for months.

    1. I use the Environmental lite pour on epoxy and other than the curing time….not bad compared to some….its really nice…no fumes…no vocs. available at home hardware and even some Walmarts and home depot ….and is a 35 to 40 dollars for the medium size kit…very glossy like glass…less expensive and not hard to use either.
      I am looking for the matte finish though…much prefer it to the high gloss….but would like to give customers a choice….this dupli comes in a matte finish more expensive than the gloss but if the gloss works I will spend the extra for the matte finish…
      no matte epoxy around that I can see so far LOL!!

  15. I like the glossy look of the engine enamel you tested, but since a hot mug sticks to it, would it work as a base coat with the acrylic enamel as the top coat, or would the latter reduce the glossiness of the base coat? Also, which resin brand works for coaster?

  16. Heather Lutterman

    Thank you SO much for this post! I’m doing tile coaster with my preschool students for them to give as Christmas gifts to their parents. Our projects are done… just needed the clear coat. Thanks for doing the leg work and testing these products! I’m going to order from Amazon right now! 🙂

  17. Thank you so much for this!
    I am looking for something on wood. Saw above mentioned “A B Clear or something” for those looking for that product I just found it: General Finishes Arm-R-Seal comes in different finishes. It’s a wipe on product though.

    Again thank you all!

  18. Valerie Demerski

    Thank you for doing this comparison. When I followed the link for your recommended choice I noticed that it states this product will give a matte finish. One of the questions on the page was from someone asking what to use if you prefer a gloss finish and it was suggested to use the laquer clear coat in protective gloss finish by Duplicolor as well. Have you tried that one?

  19. I have been doing a bunch of experimentation with Dupli Color products. I am making tile coasters that have paper images on them. I use matte polycrylic by Minwax to glue the image onto the tile. I tried spraying Dupli Color gloss products, both the engine spray and the gloss Clear coat, directly on the tile once the image was glued. The gloss only “stuck” where some polycrylic had gotten onto the front of the image. So I knew I had to put a layer of polycrylic on the image, before spraying sealer, to get a nice glossy look. Keep in mind that when you put a layer of polycrylic on top of your image it will lessen the heat resistant effect of the sealing spray you use.

    Once I put a layer of polycrylic over the image (and the whole front of the tile) I tried Dupli Color clear coat matte spray and gloss spray as a heat resistant sealer. I follow directions carefully and let the tiles cure for 7 days. I had sticking problems with both the matte and the gloss products but more so with the gloss. I even baked the tiles in a toaster oven in the garage (I bought a second hand toaster oven for $10 to use for crafts) to see if that would help the sealers cure more; it didn’t work, certain hot mugs still stuck when left for more than a few minutes.
    I then tried the Dupli Color clear gloss Engine Enamel spray. I sprayed that on the top of the layer of polycrylic. The next day I baked the tile in the toaster oven at 215-225 degrees Fahrenheit for 1 hour (just to let you know I experimented with all different times and degrees so I am just posting what time and temperature worked in the end). The gloss looked beautiful, the paper image did darken a bit and the white areas turned a pretty sepia tone which I didn’t mind because I was using manuscript illumination images. Someone doing original artwork or who wants the white to stay bright white may not like the color change. When it came to hot mug testing the Engine enamel worked great except for metal mugs. My husband has a flat bottomed metal mug covered in enamel and that consistently stuck to the tile. It shouldn’t because after you bake the tile the Engine enamel should be heat resistant up to 500 degrees Fahrenheit but I think the polycrylic layer I put on top of the image decreased the amount of heat the sealant could take before it gets sticky. All the other mugs in the house did not stick at all.
    While I was experimenting with time and temperature when using the Engine enamel I noticed that, outside of the metal mug, there was one mug that kept sticking. It is a PotteryBarn mug that is either porcelain or very fine ceramic. I finally got the right time and temperature to keep that mug from sticking. Using the same mug for experiments does work well but once you find the spray that seems to work with one mug you then have to try it out with different mugs to make sure they don’t stick. I think that is why people are surprised when a coaster works fine for them but not for someone else. It all depends on the material and thickness of the mug.
    I also worried about putting cork bottoms on the coasters to prevent scratching surfaces. I didn’t know if the cork bottom would insulate the bottom of the tile and not let the heat escape out the bottom of the tile. I just tested a finished tile with a cork bottom and everything went fine, there was no sticking.

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