Smooth-on OOMOO 30 - Bulk LOT - 1 Case with 4 Kits - 8 Pints Total Silicone

I tried doing my own pieces-parts molding for my SF modeling a bunchteen years ago. Ran out of time and money. Now I have both, decided to try it again. I had a sample pack of both Oomoo and Alumilite's stuff (from H*bby L*bby). Tried 'em both. Liked the Oomoo better. Saw this 4-pack at Amazon. At the time I ordered it, it was cheaper to buy the 4-pack than a single pack (not no more). Still, what you're now used to, you live with its foibles.(Unlike a substantial portion of reviewers of the single-pack Oomoo 30, who received packs with Part A--it's always Part A--already self-congealed, or with a substantially-shorter shelf life than the 6 months smooth-on recommends, not a one of my packs in my box was bad.)My first mold was not only the biggest one I've done so far (a rocket nose cone. A LARGE rocket nose cone--or half of one, to conserve rubber), but a learning experience (shoot, a whole college course year!) in many, many things that smooth-on does sideways. Still, with the four-pack, you can make (and replace) molds reasonably easily and economically (as economical as any casting will ever be). With the exception of how to make a two-part mold that doesn't become a brick from the introduction of Part B--smooth-on's advice on how to avoid this is worse than worthless--ANYthing that went wrong after my first mold-making could be traced back to _me_ doing something wrong, not a problem with the mold material.As said, I use it mainly to make parts for the models (SF, mainly) that I'm working. If I have one from an older model, or something neat I found that I need a dozen of (both are now in my experience), this stuff does an absolutely-amazing job of capturing it. Small stuff--I've got some greebles that aren't but a few millimeters in size (I just use a drop of resin in them; works a charm)--medium stuff--I have some models that are (a) foreign and (b) a couple of decades old, and I was able to grab patterns from them, including occasionally things I _didn't_ want *sigh*--and large stuff (like the old plastic nosecone that I wound up needing four complete ones of, and my mold didn't disintegrate even after sixteen runs of the half-cones), all worked well.In terms of quantity, I got one reasonably-large mold and a half-dozen smaller molds from each set. There's not a lot in the bottles (smooth-on really likes to sell the gallon drums), but if you work your mold-making out intelligently, you never waste a drop. I found with the first mold that I'd mixed too much Purple Stuff--both the smooth-on and Alumilite "rubber needed" online calculators bite--and that was wasted (the mold was already full). Before I made my second mold I tore through my source material and found other things that I knew I wanted, some okay-large, many fairly small. If the stuff warranted it I built a second box of lego; if not, I found that I could pour little one-piece molds into things like leftover medicine dose measuring cups (I actually did a tiny two-part mold in one of those) and some cinnamon roll icing things until I didn't waste any more (and you can actually pour the rubber into the container first and set small things down onto it; some will sink in, but most of them went only as deep as my toothpick made them).I need to get another 4-pack just because I've got some larger things done up that I need to make multiple copies of (oh, those SF models and their guns and greebles). Having learned most of the pitfalls, and how to skirt them, with my first box, I'm okay with another one. Ought to keep me busy for a week or two. :)READ THE INSTRUCTIONS. Mostly, they're correct, and you won't go irreparably wrong if you follow most of them.That said: I have no idea how smooth-on separates the parts of their molds from one another. They recommended using their own Release Agent (of course), which, it turns out, doesn't stop the rubber in Part 2 of your mold from sticking (permanently) to Part 1. Two of my molds were almost bricked into uselessness; if I fainted at the thought of dremeling and sanding and patching, smooth-on'd be a glowing hole in the landscape. Fortunately, I don't, but I was still (understandably) upset when their release agent proved useless for that. A YouTube video (gah) actually had a better answer: Vaseline. We had some upstairs that was ages old. I put a thick layer on between the old part and the upcoming part, and except where I _didn't_ get vaseline--xactos so useful--the mold halves now separated. Felt goofy 'til I washed 'em, but the whole "bricking" scenario that smooth-on mandates was no longer a problem. People have also recommended using Pam (or any generic equivalent at the grocery store); haven't tried this myself, but I may on a future small mold just to see how it compares.It's also said--and deserves to be said LOUDLY--that some mold rubbers resist tearing (as in when you mangle the mold half getting your newly-cast masterpiece out--for this, smooth-on's release agent actually comes in handy. Sort of), and some--like Oomoo 30--don't. If you're only going to make a few copies of something, you probably don't have to worry much. If you're making a bunchteen copies, for whatever nefarious purpose--like SF model building, ha-ha--then you either have to be VERY careful separating parts from molds, using lots of some release agent as you do, or you need to use a better (higher-grade) rubber than this (the Rebound series gets high marks for tear resistance). Two of my own molds showed serious tearing after just 3 or 4 casting runs (and one tore separating the mold halves). A solution to this is simple, although it kind of requires either you making molds as a steady stream or you wasting a tidge (not much). Get all your 'tearing' molds together, mix up a batch of rubber (as much or little as needed--I needed substantially less than a finger-joint-sized portion of final product), then use a popsicle stick or flattened toothpick (or even a small flat-head screwdriver)(or your finger. The stuff washes off, or you can avoid touching anything else for six hours and _peel_ it off) and slide some new mold rubber into the crack. Nothing sticks to smooth-on rubber like more smooth-on rubber, as anyone who listened to smooth-on's recommendation of their release agent now know well. Give the patches the usual six hours to cure. If you inserted too much and got a seam then trim it down, and go back to work. I've fixed every mold tear that's happened so far--Oomoo 30's not the top of the line--and haven't had a single patch give way (and I've been using my molds HEAVILY. I strongly suspect I've exceeded several of their projected service lifetimes already).Verdict? Smooth-on's customer service could be better, but this of their products is perfectly good, well-suited for both beginning casters and someone who just wants to do it on the side. Be easy with it and it'll work wonders for you. And with this much mold material, you can really do a lot. Promise.Now to save up for another four-pack... :)

I love smooth-on products and after a year went to use unopened bottles and part a was so hardened I couldn’t stir it. Don’t buy more than you’ll use in a short time

I like to mix by weight but this product is better to mix by volume as by volume it’s a 1:1 mix. I didn’t realize that I wouldn’t get a more perfect mix by weight but one color weighs more than the other. It still mixes and sets up the same but I require that all my mixes be a uniform color as I’m selling the end product and customers will likely buy multiples. That’s why I gave 4 stars on “ease of use” and “for beginners”. I will use this product but will get cups that measure and eye it.

This was my first time making silicone molds. This product was easy to use and all my molds came out perfect. Working with the pint size bottles worked well for me. I was able to make several molds from one kit.

This stuff is normally great and some of my favorite silicone. I was able to get this when it was about $20 cheaper and was a better deal then buying one at a time. However not sure how long it was sitting in the warehouse as 3 of the packages (6 bottles) where thick and clumpy and made it hard to use. I was able to stir each bottle up a great deal by hand to get it to be useful but was still pretty clumpy. After that it worked as normal but was was a chunky pour. Seems to have worked though. I do not think I will be buying this 4 pack from amazon again though due to the thickness and no telling how long it was there but I will still continue to use this product I just won't buy the 4 pack.

To make a baby doll one time you sent me the wrong silicone I didn't ask for and I try to reach out to you about it know respond back to me I spin so much money getting silicone with y'all and when I open it up it's was the wrong silicone that one time I spin over a $119.00 dollars and it was blue and pink that one I didn't over like but all the other you sent me was wonderful thank you

Exactly as described on Smooth-on’s website. It cured much faster than listed. It only took 3.5 hours (two packages mixed and poured into a block mold, at room temperature, and low humidity). The mold strength is not superb (which is mentioned in the product info on smooth-on’s website), so I am not sure how many castings I will be able to produce before the mold breaks down.

Very difficult to mix and be try heavy. You need a very sturdy wood mold for this. Plastic molds won’t work. It didn’t work for what O was trying to do. I do have mold making experience and now I need to know how to cast molds for a delicate mold that o have been working on for the past year. Maybe someone has some advice?

Works perfect depending on the application you use it for. Just follow the instructions. My advice is to mix it in a plastic measuring cup for easy cleaning after. It will permanently stick to glass if you mix it in glass. This warning should be added to the instruction. Btw if smooth on knows how to clean it off of glass, please contact me.Anyway. Great product. I make my own fishing lures in this stuff. Needs a larger bulk option with a nozzle at the bottom of the container.

my first review I made right after making some molds,this review update is because I'm completely dissatisfied with the molds I made, silicone is to rigid, cannot unmold properly. The mold ended up breaking in big pieces.