[Katherine Swift]

Hi Monica,

I’m happy to hear you are having fun with resin casting. Enjoy the journey!

Polyester resin can be tricky to work with and I generally don’t recommend it for beginners. When it comes to adding catalyst to the resin, you have to start with the end in mind. You add drops of hardener based upon the thickness of the final casting. How deep are your spheres? That will dictate how much catalyst you need. The ironic thing about polyester casting is that the thinner the casting, the more catalyst you need to generate enough heat to allow resin curing to occur.

The issues with your heart-shaped silicone mold is likely due to the mold. Castings will pick up the surface of the mold and impart them on the casting. If shiny templates weren’t used to make the mold, castings from that mold won’t be shiny either.

As for your castings, I think they are getting too hot and subsequently cracking. If you can tell me how deep your castings are, I can help you tweak the amount of hardener you use. Your room is a little warm (72 or so is ideal), which may also be impacting the heating up and subsequent cracking.

Have you considered an epoxy resin? I like polyester resin for larger castings, but based upon your description and the pictures you sent separately, I think getting polyester to work in this situation is going to be a challenge. (Plus the smell is horrible.)

[leah]

in my limited experience, depending on the type of resin you use, the ventilation is not 100% required. i have a small house and do my resin projects on my dining room table since it’s the most open area in our house (which is a pain in the winter because it’s also one of the more difficult rooms to keep warm). since i use only the low-odor epoxy resins, it seems to be just fine, at least in regards to the smell.

getting resin on my skin, on the other hand, i am extremely careful about. when i first started using resin (easy cast), i tried not to get it on my skin but i never wore gloves. and it only took a few times for me to have a reaction, not only to where it touched my skin when i cleaned out the mixing cup for reusal but also wherever the fumes came in contact with my skin (wrists, arms, neck, face) that was miserable lasted over a month. even when i wore a painter’s mask and long sleeves, i’d still have some reaction issues. i’ve since switched resin (had the WORST luck with easy cast curing anyway) and haven’t had as many issues, but now i still always wear gloves and try to avoid holding my arms or face directly over the resin i’ve just poured. so please, please be careful!

[Katherine Swift]

Hi Diana,

Yes, I would recommend the piece stay in a well ventilated area while it is curing as well. Keeping it covered to keep out dust is a good idea and will help a wee bit with the fumes, but until it has reached the demolding time, I would keep the ventilation good in the area. If you have a room that you can dedicate to resin casting, you can leave the room when you are done casting, close the doors, but perhaps leave a window open and use a fan to circulate the air.

If you get resin on your hands, I would recommend washing it off with a good detergent and water. Don’t use alcohol or acetone as this will likely make the irritation worse. I would also suggest making yourself familiar with the SDS information on the resin product you are using. Included are safety measures on how to handle spills, etc. and when to seek medical attention if necessary.

The goggles are important in case the resin splashes in your eyes and when you are sanding. It won’t do much to keep fumes out of your eyes. If that is a concern or you find you are extra sensitive to the fumes, then I would suggest working the resin underneath a ventilation hood which can evacuate fumes away from you while you are working.

We also have a safety section that goes over additional information as well: https://resinobsession.com/tag/safety

[Katherine Swift]

Great questions! While I can’t guarantee that it will completely eliminate lines, pouring the second layer of resin while the first layer is still curing will minimize them. You are correct in that you will need to do it while the first layer of resin is in the gel stage. This is when the resin is starting to cure, but not solid. If you were to place a toothpick in the resin at this point, it will be a thick, and perhaps chunky, liquid. The time for this to occur varies with every resin. Unfortunately, at least the first few times, you are going to have to babysit your resin to see when this occurs. In my experience, it happens within the ‘double the pot time’ range. For example, if the pot time of the resin is 30 minutes, the gel time will likely happen within 60 minutes. The gel time usually only happens for a short period of time, so you are going to have to watch it closely and be ready to pour your next layer.

As for pouring only 1/2 inch at a time, that also depends on the resin. Some have recommendations on thickness of pours, while for others, it’s more about the volume.

[Bethie]

So I tried this out on Saturday night. I mixed the resin and boiled breast milk together and poured into the mold. Its been curing for 36 hours now and its still sticky. Did I do something wrong? This is my first time I’ve ever used resin.

[Katherine Swift]

Hi Samantha,

For the best results, I recommend using colors designed specifically for resin. Resin hates moisture, so other colorants such as paints, can keep the resin from curing. With that in mind, I certainly think it can be fun to experiment with other colorants. You can see my results here using some items I found around the studio: https://resinobsession.com/resin-resin-resin/experimenting-with-resin-colors I haven’t used the Pebeo based paints or a solvent based paint. I have used alcohol inks, however, and been mostly happy with the results.

[Julie]

I am now on my fifth fish bowl and I am still getting terrible results. I
did coat my polymer project with resin two times. I also sprayed my project
twice with Castin Craft Resin spray. After it dried I heated items under a
desk lamp and kept all items warm while curing. It seemed as if the clay did
“okay” but I am now getting the “force shield” result in the middle of
everything. I used 8oz of Castin Craft casting resin and 16 drops of
catalyst. Ugh..I am sooo frustrated. I am not sure how to attach pictures to this to show. Do I have to wait until SUMMER?????? When it is HOT all over? I am in Oregon and it is not cold. Sigh..

[Katherine Swift]

I would try using the clay and bowl with the lamp in a hot box shown here: https://resinobsession.com/resin-resin-resin/casting-resin-in-cold-temperatures The box will help keep the heat in.

I don’t know about warming the bowl in the microwave. I’m worried it would create hot spots (similar to reheating food) that may impact curing. Instead, I would put the bowl in a hot water bath to make sure it is warmed up evenly. Assuming it’s winter where you are, I don’t think house temperature is warm enough for inanimate objects. If you try heating the bowl in the microwave, let me know if that works.

[Katherine Swift]

Hi Julie,

My thought here is that the film you see is air trapped next to your embedments. It could be from air released from the object during casting. Resin curing is a heat reaction. Sometimes that heat can cause air to be release during the curing process. The other possibility is that the surface tension of the embedded objects is trapping air. I don’t think the resin is a problem since you mentioned things are curing normally.

Here are a few suggestions on what you can try to prevent this in the future:

1. Dip your pieces in resin and allow them to cure on wax paper before embedding them in your fish bowl. That will reduce the surface tension. It will also seal any air in.

2. Seal the items with a two to three layers of our acrylic sealer spray before embedding. This will also seal air in.

3. Make sure your items are warm before including in the resin. That may allow air to escape before you put it in the resin. If I were going to do this, I would warm them up gently with a heat gun. https://shop.resinobsession.com/products/zap-embossing-heat-tool It wouldn’t be a bad idea to make sure your fish bowl is warm as well.

Let us know if this helps!

[Katherine Swift]

Hi Suzette,

The easiest way to make a frosted look would be to sand your pieces with wet/dry sandpaper once they are finished curing. I would suggest something in the 600 to 800 grit range. It will ‘frost’ the surface while still allowing you to see what’s underneath, colors are otherwise. Perhaps you have a couple of resin mistakes you can practice on first. 🙂

[Katherine Swift]

You can push the rhinestones in when the resin is tacky. They will stick, but the resin itself is very flexible. You have to be careful that you don’t distort the shape of the piece. You can see how resin is flexible partway through the curing process here: https://resinobsession.com/resin-tutorials/diy-tree-ornaments

As for casting resin stones, then casting a resin piece behind/under them, you will need to find a way to cast the stones in place first. That will require casting the stones in the mold (thus several turns and several castings).

[Erin]

Amazing clear cast, I figured out that the reason it was making the ugly bubbles is because the inside was curing faster than the outside and that was causing it to shrink. So to combat this, I took a lighter and heated the outside of the jar before the inside began to fully cure. It solved the bubble problem, but the resin then cracked. .-.

[Katherine Swift]

Hi Tory,

Age of the resin is my concern. I recommend users only purchase the amount of resin they can comfortably use within a six month period. If your resin has collected moisture, that will certainly inhibit proper curing. Let me know how it goes with a new batch.

[Katherine Swift]

Hi Kimi,

That’s a great question and one I’m working on in my experiment series. (Unfortunately, I don’t have enough experiment results yet to share.) Where the trouble comes is that clear resin itself has colors in it to achieve a final clear look. (Resins tend to be a bit on the yellow side whereas the hardeners tend to be on the blue side.) The problem is that one brand’s colorants may interact with another brand’s colors in the resin and/or hardener.

In general, I have had success using one brand’s colorants in another brand’s resin with the exception of Alumilite green. I have found despite everything curing appropriately, when used in at least two different brand of resins, it will turn blue.

At this point you have two choices:

1. When using a brand of resin, be sure to use their colorants.
2. Experiment a little, knowing you may run into a problem from time to time.

[Katherine Swift]

Hi Tatiana,

Here are a couple of my thoughts to help you:

1. Are you absolutely sure you are measuring and mixing properly? It sounds like your castings are initially curing properly, but I would be 110% sure your measuring and mixing is spot on. I like to use graduated mixing cups to make sure I am exact, then mix for 2 to 3 minutes while scraping the sides of my cup and stir utensil.

2. Are you using anything else besides flowers in your resin and/or are your flowers dry? Excess moisture can keep resin from curing properly.

3. Are your resin charms going into metal settings? Metal settings when displayed in the heat, will pass that heat onto the resin. I have seen resin melt in these situations.

4. Are you castings thin? In general, Easy Cast resin is a relatively soft resin, even when cured. I could easily see a thin casting made with this resin and a little bit of heat applied make it ‘bendy’ rather quickly.