Smooth-On OOMOO™ 30 Tin Cure Silicone Rubber, Easy to Use Silicone Mold Making Kit, Pint Unit

I buy these pretty frequently for work and it's currently my favorite silicone for making molds. I've bought about 40 so far and would say about 15% arrive unusable, either from leaking or one of the components being completely coagulated (not the fault of the shipper by any means), but it's amazon so getting replacements isn't difficult, especially since here in the US they typically arrive within a few days of ordering. If you are going to do a large pour with multiple sets, make sure to give each container a shake to make sure they're all ready to use. I've had no issues with thick pours (3-4 inches thick), just make sure you shake both containers REALLY well before use and make sure it's very well mixed and it is on solid colour without streaks or spots before pouring. It cleans up very easy, if it is mixed and spills, it peals off so satisfyingly after curing. After opening, I would recommend using it all within a week. It will cure while in contact with many things other silicones won't, like wood, polymer clay, and cured silicon of the same type(I like to use previously made molds as filler to save on material, just make sure it's cleaned very well with soapy water then let dry). I mix by weight, not by volume and typically end up with extra part B After having use all that I need from a set, I like to let the remanence of part A drip into a cup until there are no drips left, then mix with the proportionate part B and let set, then that can later be used as filler material on a later mold. I RECOMEND USING A SILICON TO RESIN RELESE SPRAY IF CASTING RESIN INTO YOUR MOLD. Definitely a fan of the quality and it's pretty easy to use. Definitely recommend vacuuming after pouring to get rid of air bubbles, not always 100% necessary but it helps. I've never had a batch not turn out so if it's sticky or doesn't set, it's most likely user error. I always let it set for 24 hours, longer shouldn't be necessary. The company doesn't like giving refunds in the event of the product arriving unusable so if a return must be made, do it 100% through Amazon and not the seller. That's about all I can think of to say about it.

I am a doll sculptor teaching myself how to make replica parts of my pieces to expedite production, and I've experimented with a few different products for casting parts and replicating them: none of them beat out the results I got with Smooth-On! The 1:1 ratio is very simple and while you will waste some product in your first couple of rounds, you very quickly begin to be able to eyeball the measurements per mold; I've made 5 now and I can pour without weighing the pieces, without wasting product. I began with using foam core and hot glue to create the vessels in which to pour the silicone onto the pieces, but it was very messy and time consuming; I now swear by using Lego bricks instead and wrapping the edges of them with Frog Tape to avoid leakage. I haven't had any issues with curing, perhaps because every time I pour I mix each part in their respective pots for about 30 seconds before I pour to mix them. I'll then use wooden skewers to mix them together for about a minute before preparing to pour. I use a small spatula to help get the silicone off the sides of the mixing cup as I pour, ensuring I use as much product as possible per batch. Two-part molds have been easy and amazing with this. Just be sure to use sulphur-free clay and make keys in the clay before making your first mold part. As for the second part, I have the best results with simple Vaseline; I use a cheap paintbrush to apply the Vaseline to the mold and get into every crevice. I've had molds ruined with mold release spray not working well enough, but never had a single issue separating my mold parts with Vaseline. Smooth-On also makes my favorite material to cast my molds: their Liquid Plastic! The drying time is very fast and I can easily sand off the seams with fine grit sandpaper and buff it with a polisher. If I need to patch anything up, I can use air dry epoxy clay. Overall, Smooth-On is by far the brand I trust and have had the best results with as a self-taught mold maker and sculptor!

I thought this product worked pretty great. I didn't read the reviews before hand and I guess I'm glad I didn't. As the description state, this is a product has two compounds that come in two different bottles. You measure (I just used a regular measuring cup) the same amount for both compounds, mix thoroughly and pour into/over whatever you are making a mold of. One bottle will have a blue compound that is a thin-ish consistency and the other bottle is a pink compound with a much thicker consistency. I did read some of the other reviews and they mention getting the product and the pink compound was super thick, "chunky" or even solid. The instructions that come with the compound do mention that the product does not have a long shelf life, and actually recommends using it ASAP. So I am guessing that is what happened to other people, they either ended up getting the compound that had been sitting around awhile or didn't use it fast enough after they recieved it. The instructions mention using a releasing agent, I didn't. It worked out fine for me. I was using several different objects of different types of materials to make molds of and I didn't have any issue de-molding anything. I'm not going so far as to say you don't need it, but I would say that I don't know that it is necessary. I will say the objects I was making molds of didn't have a lot of nooks and crannies that the molding compound would make it's way into, most of the surfaces were flat and smooth. I thought there could be some more clarity in the instructions. The instructions mention a "cure time" and a "pot time". Cure time is pretty self explanatory for most people (how long it takes for the product to set up.). But I wasn't and still am not sure what "pot time" is. I have an idea, but again, not 100% sure. My one big piece of advice for using this would be to have a game plan in place before you start making molds. I had a vague idea of what I was going to do and ended up making a bit of a mess. The two compounds have different consistencies so an idea of how your are going to mix these thoroughly is necessary. I mix these compounds in a dixie cup with a chopstick (I realize now how ridiculous this sounds) and I thought I had mixed it well, when I went to pour the compound into the cookie sheet I was using I saw there were parts that hadn't mixed as well. The instructions call out that mixing it thoroughly will yield the best results, so I felt like i was kind of scrambling to get it all mixed before the compound started to set up. I did mention before, the mess. This is a really messy process. Luckily I found that clean up was SUPER easy. I was kind of worried about it since I was getting compound all over my cabinets and hands and everything. But I wiped up most things with a paper towel and then soap and water after the fact. Very easy to clean up.

Before you open and use this look at the product batch number, the lower left corner of the bottle front... It's in the format below... 2208XXX equals August 2022 OOMOO had a 9-month shelf life, so if your batch number is over 9 months old it's expired and potentially no longer any good... I have been using Smooth-On products (and other professional grade silicones) professionally for decades in the movie props industry, but I have never used the more consumer-friendly 1:1 mix OOMOO line... But, as it goes, I needed something in a pinch for a small project so I figured I would give it a try... Upon opening it I noticed the yellow bottle (pink) was very thick, but I didn't think much of it as the blue bottle (blue) was pretty liquid and I thought maybe that was just the way it was and would even out, but upon mixing it, it became obvious something was wrong as the final mix was THICK, well beyond any pour grade silicone, much more like a vertical surface brush on silicone... I didn't even try to pour it, it wasn't going anywhere unless I scraped it out of the mixing cup, it didn't even self-level in the mixing cup before it set up... After talking to a few people more experienced with OOMOO products they told me this is the tell-tale sign of it being expired aka past its shelf life, and sure enough, I looked at the batch number and saw it was 10 months old... Only a month past its shelf life but long enough that it was spoiled... Amazon replaced the first order, but the replacement order was also expired, so I got a refund... So beware, you might be getting an expired product that might or might not work... Hopefully, the seller takes note and rotates their stock out and pays better attention to shelf life in the future, as Smooth-On makes great products overall, as long as you use them within their shelf life period...

I was working on a small project and figured I'd give this a try. I've used Smooth-On products before, so I know that you get a good product. I was working on a small project with a small budget to play with (and I like to experiment with different materials) and this did the job. In hindsight, I should have purchased a silicone with a lower shore value since my mold had some undercuts and this tears pretty easily if you aren't careful de-molding, but I did a few small tests and was prepared to be very careful and had no problems. Only drawback is the 6 hour de-mold time. I'm used to products that set in under an hour, but I knew from the description what I was getting so my impatience is my own fault. LOL On the plus side, having 30 minutes of working time is a definite plus (as opposed to 5 to 10 minutes that I'm used to). It captures the detail very nicely and works well with Plat-Sil thickener to thicken it up for brushing on in places where it can tend to drip down. I've made multiple castings from my mold and it's holding up perfectly.

Excellent stuff. Mind you, my mold-making is in its infancy, but this material is proving to be a good place to start. It mixes at a 1:1 by volume, which is helpful for those of us whose basic arithmetic is somewhat lacking (such as myself). Part A is significantly more viscous than part B. Be patient when measuring it out, as it does have a tendency to overshoot whatever it is you're trying to measure to. I've been using the lines on two separate solo cups for measuring my components. I've also been mixing in a bowl-shaped tupperware container (polypropylene). The cured rubber pulls right out of it. Be wary about using glass; the cured product stuck quite efficiently to a glass stirring rod that I used, which I'm just gonna have to take the time to scrape off. Spraying a mold release on any glass items you're using may do the trick. The rubber cures with a good flex, but still stiff enough to cut with a reasonably sharp knife. The instructions say to bake for four hours at 150F after it's cured to rid the mold of the alcohol that's produced as a by-product of the reaction. Now, a word of caution: When setting up your material for the pour, make sure you're within the bounds of one quart of liquid. Expect to go through no less than a full kit for a large mold! If you find yourself trimming off a lot of your mold, save your offcuts; they work nicely as fill for subsequent molds. The extended cure time is a godsend. Every detail comes out and there's not a single bubble on the workpiece. I molded some metal parts and found that even the particularly fine grind marks on the steel came through in the silicone. Allegedly, oomoo25 also does not require degassing, but I remain skeptical. All in all, this stuff's great. Take your time, be patient, get everything set up properly, and have fun!

I was making a critical figurine and first bought Mold Making Silicone Rubber 30A from BBDino Direct and it was awful. If I hadn't thrown it out, I should have returned it for a refund. It didn't cure correctly, stuck to itself even with mold release and was just awful. I then ordered the Smooth-On 00-30 Trial Kit. I've used this before, but was looking for something a bit less expensive. Big Mistake. The Smooth-On product works Great. It cures solid in 4 to 6 hours (Same as the other product) but does so with no sticky surface. While you do need mold release to separate the mold halves, I forgot the mold release and still got the mold apart and made great parts. You get what you pay for. Smooth-On is made in Pennsylvania. The other product was made in China.

Great stuff, very handy for a variety of uses, including creating molds of course. I've used it for forming air-tight interfaces between hoses and containers, which works well as long as there's not a lot of stress on it. It does tear fairly easily (Which is noted on the product page), so it's important to support it properly or embed structural pieces to help it deal with force/pressure. This isn't a big problem if it's used as indicated, it's using it for other purposes where this might be a problem. I do like how much you get for the price, which seems very reasonable for almost 3 pounds of silicone. My next buy will be some stronger, platinum-cure silicone since it seems to be the best for high temperatures, strength, and a quick cure. The only real downside I'd note is that it is very sensitive to lower-than-ideal temperatures when curing. They recommend using and storing it in the mid-70's, since anything much cooler will result it an extremely long cure time, assuming it completely cures at all. This isn't a disaster since it's easy to apply moderate heat to "set" the cure permanently, just something to be aware of if it seems to be taking forever to cure.