One of the things I love about living in Florida is that our winters tend to be quite delightful. And by delightful, I mean I can wear flip-flops pretty much any day of the year. It also means I don’t have to worry much about casting resin in cold temperatures. But I know many of you aren’t so lucky, so here are a few of my cold weather resin casting tips.
But before we get into that, you need to know this about resin:
When you buy two-part resin, it comes in two bottles: resin and hardener. When you mix them together, a chemical reaction occurs that produces heat. This is what causes your resin to harden. The ideal room temperature for this to happen is 70 to 75 degrees F. That’s not so difficult to achieve during the summer, but during the winter, it can be challenging.
So here are some cold weather resin tips to make sure your resin cures hard and clear:
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Tip 1. Create a resin ‘hot box.’
Take a large box, and include a lamp with an incandescent bulb. Turn on the light while your resin projects are curing. The incandescent bulb will create a little heat, and the cardboard box will keep the heat inside. Be sure to cover your projects, as those bulbs also attract dust. You can also use a metal cabinet for this.
⭐️ BONUS: Here are other resin casting tricks I always use.
Tip 2. Cast your resin in a smaller room and use a space heater.
Make something like a bathroom or a walk-in closet your resin casting room during the winter. Turn on a small space heater while you are casting your resin. The heater will bring the space up to the low 70s without turning on the full heat to your house.
⚠️ IMPORTANT: Please don’t leave a space heater unattended.
⭐️ BONUS: Here’s the resin supply list you need to save you time and money.
Tip 3. Warm your resin before using it.
Put your resin kit in a warm water bath for 5 minutes at a time before using them. Not only does this warm up the resin, but it thins it out, too, making it easier for the resin to release bubbles.
⭐️ BONUS: Here are other ways to rid your projects of resin bubbles once and for all.
Tip 4. Warm your mold before adding resin.
Before pouring your warm resin, in your warm room, into your cold mold, run a heat gun over the mold first. This helps the resin retain its heat instead of the resin warming the mold.
⭐️ BONUS: Here’s how to use a heat gun for more than just heating a mold.
Tip 5. Plan ahead.
Use your resin when the outdoor temperature is going to be the hottest. That might mean checking the weather and rearranging your schedule to pour resin in the middle of the day.
⭐️ BONUS: Here are more resin casting tricks to make things easier for you.
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Thank you for the tips! I hadn’t thought about a ‘hot box’.
For curing shelves, I bought some really cheap stacking horizontal letter/paper trays at Staples. The clearance between trays is enough for my smaller molds and a low cover. Since the top tray is open on top, I put larger stuff there or even end up stacking mold-cover-mold-cover. I put parchment paper or wax paper down on the tray before putting a resin filled mold on it. If there is an over spill, it won’t stick to the tray.
Link just for the visual of what I mean by letter tray: http://www.staples.com/OIC-Plastic-Stacking-Trays/product_SS997913 I think mine were cheaper yet ’cause I don’t care what they look like.
Thanks @Rijacki for sharing
Thanks for the hotbox idea! It took my last resin project a week to cure as we keep the house under 70F in the winter.
Even here in Atlanta we have plenty of cold days (like the rest of this week!). In cold weather, I first try to do my resin casting upstairs, as it remains warmer there (heat rises…), as opposed to downstairs, even though downstairs is more convenient. Sometimes I will just set up a small, square folding “card table” on which to do the project in a corner of the living room. Then I also keep a small, adjustable desk lamp pointed over the project while it cures. And I keep the project covered using the most appropriate size (based on the number of pieces in my run) of clear plastic storage bin/container (slightly raised up on at least one side to allow for air flow but to limit dust and to help concentrate the heat from the lamp’s light bulb for warmth).
Hi I was wondering do you think I could work on the resin in my basement then give it a few hours to set and then bring it upstairs? If you think that would be ok about how long would you wait.
Thank you
Teri
@Teri, how warm is your basement? What kind of resin are you working with?
These are all great tips, does anyone here use UV lamps to help cure?
UV lamps are only helpful if it is a UV resin.
Hi, yeah I have used UV lamps for the UV resins and tried underwater curing. However, I obtained curling. Is there anyway to get rid of the curling of the edges? do you know what is the curing time underwater?
I haven’t used UV resin much and can’t make a recommendation. I would suggest asking the manufacturer for help.
Hello,
Just wanted to share my method of dealing with cold temperatures!
My room is absolutely freezing! Not ideal for resin.
I was really confused as made two pieces, one cured fine the other was still taccy [I always take great care to mix and never encountered non curing or taccy resin before] . I then realized the piece didn’t work as I was including a large metal disk in the resin and the metal itself was cold as ice.
My solution? As well as warming the resin before use, I didn’t have a suitable lamp to make a warm box so I used a small hot water bottle I had.
I placed it inside a wooden art box suitcase type thing, I’m sure just under a regular cardboard box would be fine too and placed my resin pieces on top.
It worked like a charm! Perfect for my metal pieces as maintains a warm temp in the inclusion and stops them going ice cold again.
Thanks everyone for sharing you advice and I hope this might be of help to someone too!
I prewarm my resin in a water bath, and my molds in a food dehydrator. Then I let them cure for 12-24 hours in the garage (This is TX, so it’s 60 in there overnight). Then I demold and place the pieces in the food dehydrator. I run that for a few hours, let them cool down and I have rock-hard cured resin.
Thanks for the tips!
I have only one question: I have to warm the resin AND the hardener (or catalyst)???
Thanks!
Yes, I would suggest doing both.
Thank you for this great information! Fall is definitely arriving here in Kentucky, and it’s only 66 inside the house. I’m just going to wait till around lunchtime when it warms up a little bit more. Thanks again!
I live in England so it’s very cold here, we usually have the heating on would it help to place my resin in its mould son a radiator?
I would not put it directly on the radiator as it may damage the mold.
? Turned my shed to a studio. Come winter and cold i have a small heater. But u can see the hot coils. If u tip it it cuts off. Hubby concerned about coils n toxic resin. Is this dangerous. Ty
I’m not sure I understand your question. Are you worried about getting the resin too warm?
I think they were somehow concerned about the red heating coils in the heater and the fumes from toxic resin, that the heater would somehow ‘ignite’ either the fumes or perhaps the resin itself like a flammable liquid like gasoline.
At least that is my estimated guess to what the above commenter was asking about dangerous.
I’m VERY new and VERY inexperienced with resin and just started. I’ve only done it twice (first time was MAJOR failure, 2nd time was just last night). Here’s my big question. I’ve been reading through all the great info here and I see that you can cover the resin projects with boxes and lids. My big problem/question is can resin projects be placed in a closed drawer or a cabinet with doors shut as it cures??? I rescue cats and have started resin as a way to hopefully bring in some funds for the rescue but that means I HAVE CATS lol Some are sweet but then some do everything possible to get into trouble. I have a small old house which is very cold right now. My tiny bathroom is not working out well with balancing projects on the tiny (only) shelf I have in there with the heat vent open. I’m kind of at a loss right now as to how to keep projects safe, both for the project’s safety and the kittens. 🙁
Hi Laura, I understand it can be stressful trying to keep your projects safe while they cure. Yes, you can put them in a drawer while they cure. You could even include a heating pad to bring up the temperature.
2nd time turned out AWESOME! I read many many articles here and did the following: put the bottles in XL bag then into warm water bath about 10 mins before starting. While mixing slowly, I had a heat gun on low blowing toward cup. Turned out crystal clear! PROBLEM – finding a “safe zone” to cure. 🙁 My idea of having piece in bathroom was a good one, but they got bumped and therefore pieces were “uneven”, almost like they were tipped so one side is higher. Also even tho I had cardboard covering the top, there were still a few friendly cat hairs that snuck inside. I’ve read so many different things, so I’m nervous/unclear about how exactly they can be stored as they cure. They can be placed in a drawer or cabinet with doors shut. I actually have a dresser with shelves that I may just use for resin to cure. I can put the projects on the shelves and then place a heating pad somewhere on one of the shelves? Does it need to be a certain distance away from the projects? or can it be next to? I’ll bungie cord the door shut so they can’t get to anything. This will be ok? I love the tutorial on the cheese board and would like to try it! 🙂 THANK YOU SO MUCH!
Hi Laura, your heating pad should be close enough to your project that it can absorb some of the heat.
Would it be better for the primer and resin to penetrate the wood if the resin and hardener are hot?
Hi Pouria, I’m not sure I understand your question. Can you tell me more?
Thanks so much for this article. I’m very new to resin and I have questions about the curing process. I plan on mixing and casting the resin outdoors since I have a small outdoor space but I’m having trouble figuring out where to leave it while it’s curing. Resin is still toxic while its curing and I’m trying to avoid bringing it indoors while it cures for that reason. However, I can’t leave it outside to cure even if I cover it because it gets to about 50 degrees at night where I live. I have a cat and I don’t want to expose her (or myself) to the fumes at all by bringing it indoors. I live in a small apartment and I have an extra closet where I can leave it to cure indoors. I’m wondering if I can leave the resin inside of a cardboard box or storage container, in the closet, while it’s curing? Will I still be breathing in the fumes? Am I being too cautious about this?
Hi Lindsay, I appreciate that you are taking resin safety seriously. I wish everyone did!
Firstly, you should be using a resin that conforms to ASTM D-4236. This is a resin that has been reviewed by a toxicologist and deemed safe for use for art purposes in any location. All of the resins sold on Resin Obsession have this certification. You can find them here: https://shop.resinobsession.com/collections/resin.
For more details, you can consult the safety data sheet for the resin you are using. It will make detailed recommendations as to how to use the resin safely indoors. Not all resins have the ASTM certification nor will the manufacturer provide safety data sheets. This is unacceptable in my opinion and I would never use a product like that.
If the mold and epoxy is cold in a cooler room, will it cause the mold to stick to the epoxy???
Hi Tracy, there are a lot of reasons why resin could be sticking to the mold. Here’s a discussion I found in our forum talking about this topic: https://resinobsession.com/forums/topic/resin-sticking-to-my-silicone-molds/
hi! ok a few questions. i did my first poly resin cast indoors as its 50 degrees here and i’ve had the space well ventilated but the smell is taking over… i read above that you can store the cast while it’s curing, so i assume that i can put it in a box (probably will try a tupperware container) and let it sit for at least 24 hours before taking it back out of the storage container… does that sound ok to do? i pretty much just want to put the cast somewhere so the smell will stay contained instead of spreading throughout the house. next, if i were to use a heating pad, i guess i don’t understand how to do this? do i put my storage box (not a tupperware container in this case) on top of the heating pad and use it on low heat as to not overheat the cast? i need more, transparent information as i am new to this! any input would be greatly appreciated. thank you!!!
Hi Hal, there are examples of using heating pads in theses articles:
https://resinobsession.com/resin-resin-resin/resin-casting-in-cold-weather/
https://resinobsession.com/resin-resin-resin/how-to-get-your-resin-to-cure-in-cold-weather/
You could go down to your Sporting Goods store and get some hand warmers Walmart carries them and they get warm enough to cure your resin
Can I use a heat gun on my almost liquid uncured resin? It sat out all night at 68 degrees
Hi Carol, what’s the expected cure time of your resin?
A little late to the party here, but what do you think about the resin heating mats? Is it OK that the mold is directly touching the mat?
Yes, I think that’s fine provided the mat only gets warm, and not hot.