DIY Silicone Molds - Excerpt

so we can go ahead and uh make our object i'm gonna set this to the side and get some all right so we're going to be using this 100 silicone uh it's important that it says 100 silicone on it it's also important that on the back you'll read the instructions and it's will say on their acetic acid released during cure or acetic acid is involved in the curine what you what will tend to happen is that when i've taught this before when i used to teach at glass casting community college they would get something called like silicone plus or silicone advance or something that just means the company added probably latex to it to increase its flexibility or its ability to get into little crevices and things like that we don't want that we want 100 percent silicone and we want acetic acid involved in the curing process of it then we're just going to use some water just regular water nothing special um and the the if you go online there's tons of videos on how to do this and the main thing that i see wrong with it is that they add in way too much soap which isn't necessarily going to harm your mold but it's completely unnecessary the other thing is they make their molds way too thick you have to let air it needs oxygen so i usually add about two tablespoons or so you just wanna feel it the water should get start getting sudsy we can go to the over top you can see that suds are starting to form in my water uh that's what we're looking for and it should feel a little slick on your fingers hands and then we're going to go ahead and add our silicone we have our cheapo caulking gun these caulking guns often have a opener on the side here it's a little secret that takes the tip off and then if it's a good one then it has the needle so you can puncture the interior uh membrane in there that holds the silicone inside the tube if you don't puncture that membrane the silicone comes out of the back of your tube there which is not fun so i can go the overhead i'm just going to squirt just basically like i'm making noodles or something uh i'm not gonna try to get it all in one spot i'm gonna move it around what we're trying to do is coat all of the silicone with the soapy water and you don't have to unload the whole tube just enough to get started release the pressure on that set that aside and so unfortunately gloves make this more difficult if you put on nitrile gloves the nitrile gloves will tend to stick to the silicone a lot more unfortunately one thing that you can help is sometimes i'll put a little just a little extra soap on my hands to really lubricate my hands to make sure that the silicone doesn't stick but it really is not as horrible as getting silicone on your hands if you uh have ever used it to caulk your bathroom or something like that you can see that it's not sticking it just falls right off can we go to the front view it just falls right off my hands it's not sticking at all what i'm doing now is just sort of gathering it up pulling it together into a little nest of silicone making sure that it's nice and evenly coated and now i can start to pull it out make sure both your hands are soapy and then i'm just going to start almost kneading it i'm not going to squeeze too hard because the interior of the silicone hasn't been coated with soap so it's still a little sticky even if my hands are coated it might stick a little bit so i'm just very lightly sort of moving it back and forth making sure to get the rest of it so this process uh reasons why you do this is one it's it is cheaper it ends up being cheaper um you know a tube of silicone you can sometimes find at some of the like dollar stores or some of the pound stores or wherever whatever sort of cheap store you have for relatively inexpensive these tubes were four dollars uh and i'm going to get um i think it's like 10 ounces it's quite a bit of material especially because we're not making the mold super thick and you can see now i've pulled off a little bit and it's just um we can go the over yeah we're still on the overhead i've pulled off a little bit it's not sticking to my fingers it's pretty easy to manipulate and i can push it around and that's really what we're going to be doing so you can see i can just start manipulating and pushing around what you want to do is put it on your object and just start patting it soft and i want to be able to see my object through the tutorials i see online that go wrong it's because they just start glopping a ton of it on there and that's never going to cure or it's going to take forever to cure so it's much better to do it in layers you know silicone doesn't like to stick to anything but itself uh so if we just start padding on and making a really thin layer uh then we can start to capture quite a bit of detail and because we can push in we can push it into to find details of things you of course will not get as fine a detail as you would get by using a portable silicone like the smooth on product that i recommended on the supply list but you can get really good reproduction of release of simple forms i've done uh you know anywhere from sticks to uh capturing the text on uh coffee cup lids all sorts of different things uh in order using this process and it just tends to be a little i don't want to say it's slower but you have to add you have to do it in layers so you kind of work on it step away come back and build up all those layers so i'm just going to keep adding a few more a little bit more just going around and what i'll want to do is eventually cover this whole object even the base here because i want to be able to cast that in plaster as well side add a little more silicone so while i'm doing this if anybody wants to unmute and ask a question that's totally fine you're not just watching me i have a quick question so when you're patting it on um just because we like i can't see the detail of how you're touching it but are you suggesting that um like you're not i notice that you're not smoothing it but you it looks like that padding is the way that you connect the layer is that right like yeah so i'm uh i'm patting it let's see how close i can get without it blurring so i'm just sort of pushing it in you know i'm not smoothing it because that's going to pull it away from the object once you have your first layer then you can kind of do that but right now i'm just sort of like patting it you know just pushing it um lightly into the surface does that make sense yeah that's great it's good to see it up close yeah so i'm just sort of adding it and then because silicone that's not going to stay on i'll fix that later so i'm just going to keep adding it and i want to cover all the things i want to cover in plaster so yeah that's what happens i start talking up something like i love sticky wax and then it fails during the demo that's par for the course um so the tendency is want to keep going but i want to make sure that it stays relatively thin and i'd rather add another layer after this is fully cured in about an hour then wait 24 hours to do a layer so that's the difference is if i get it so thick that i can't see my object anymore i'm probably going to be have to wait until the end of the day to do my next layer but if it's just like this where i can still see quite a bit of the detail of the object and it's just a really thin skin coat then this is going to be ready for another layer in about 45 minutes to an hour and that's much more desirable than like waiting then globbing it all on and having it not set um the failures that i've seen is having this mold be too thick then it feels like it's all set up it's hard it's rubbery and it's you're so excited and then you cut it open and the inside just oozes out because it never sets it does need some oxygen to set although acetic acid is the main thing uh it does need some oxygen and exposure to air in order to fully set that is one note why this process is people don't like this is it does smell like vinegar really intensely if there if you could transmit smell through zoom you'd know what i'm talking about but it smells like vinegar i'm just going to set this aside for a second and start to let that set up so i just want to set that aside and and this is often when my own studio when i'm doing this process is i'll do a layer and then i'll go do a million other things so it's a it's definitely a multi-tasking process glass casting because there's a lot of waiting uh so especially with the silicone mold making process um clean that up do that so i've got my uh silicone mold here uh it's starting it's already started to set up i could there's a few areas they're still a little soft but we can go ahead and move on uh to the next step and start adding a little bit more it's a little thin at the top there are some other areas that are a little thin but for the most part it's already starting to come together let's see where's my water i don't water my silicone here so i can go ahead and add another layer but there's another way to make a thicker mold a lot quicker um which is uh to add i thought i had a i just need like a ziploc bag do you have one i think i put them in the yeah can you go grab one sorry guys uh she's gonna grab a ziploc bag for me uh so if there are any questions you can go ahead and unmute i can answer them now uh but basically if you add cornstarch to the the heart to the garden store silicone that you get you the silicone will set up a lot faster and you actually make a putty like material uh which is actually really nice for making a nice thick uh silicone mold so a little cooking show magic here here's one that i made earlier of the same form and it's nice and thick and it's an opaque color because i made the the putty like form from it uh when heidi's backing can switch the cameras i'll do a little detail of it but it's a nice way to thicken up your silicone mold without it taking forever to set up and you'll see it sets up really quickly sometimes even before i can get it all out of the bag so i'm just going to put some uh silicone into the corner of this ziploc bag you don't need to use a ziploc bag but it makes it a lot less messy if you do it outside of some sort of container this cornstarch gets everywhere and it's just not very pleasant so i'm just going to put some into the corner of the ziploc bag uh and then for about this much can we go to the up this much silicone i'm going to add about a tablespoon of cornstarch but really it's going to be about feel and making sure that it just gets to the right consistency if you add too much it'll get too thick and kind of grainy so it's better to add a little bit at a time and then add more as needed so i'm just going to add about a tablespoon sorry for those of you on the metric system seal that up and then i'm just gonna knead it making sure that it gets nice and incorporated and i want it to be a putty like consistency when it's all done um it will also go opaque or like a translucent color uh more so than um than it normally is so that's also a way to tell when it's ready the other way to tell is to just cut it open and see if it's uh sticking to your hands if it's sticking to your hands you need a little bit more cornstarch because the cornstarch will also help with the the sticking so i'm gonna add a tiny bit more because it's still not quite there the uh vinegar smell is really intense right now seal that back up go ahead and start together pushing it always pushing it to the corner of the bag so that we can get it out what we're going to do is cut the corner of the bag uh so that it works like a pastry bag just work into the corner and kneading it together making sure that that cornstarch is all in there go ahead and cut the corner i'm going to just soak my hands so that they definitely doesn't stick to them and then i can squirt it out and you can tell it's more of like a putty like consistency and uh jewelers actually will use this to like if you want to make a mold of a cabochon or something like that you can smoosh this onto things and get like a mold of a button or something like that and they actually sell silicone putty that you can buy it's stupid expensive when it's basically just cornstarch mixed with silicone and you can color this if you add some food coloring to your cornstarch you can make it different colors so it's pretty but it's just a little bit it'll you can make this mold thicker and it'll set up as opposed to this method the soapy water method where if it gets too thick it'll take forever to set up this yeah i can go ahead and just pour on just dump on a bunch of it and it's not going to really stick to anything and i can make it a lot thicker it doesn't i found that it doesn't get as great a detail so i tend to start my first layer with the soapy water method and then i'll thicken it up using this cornstarch method but again i'm just sort of patting it to smooth it out and spread it out but i'm not as concerned about it being too thick with this method and the cornstarch aids i'm not exactly sure what's happening chemically in it but it does cause the silicone to set up a lot faster my assumption is that it's pulling some of the moisture out of the material but i'm not entirely sure if anybody knows what's happening feel free to share uh but a lot of soap makers or candle makers will make quick molds this way also jewelers but it's a nice way to make kind of more of a putty like material that will set up super fast one thing to do when you're making a mold like this even if you're just doing a brush on or if you're doing it this way is to make sure there is there's an area where you're the area where you're gonna cut the mold open so you can get your object out of it that it's nice and thick so i tend to bead up in a long path along here and make sure that's nice and thick and that's where i'm going to cut because you want to make sure that when you cut your mold open that that thick area will come together and seal together seamlessly so you don't get any material leaking out or the mold doesn't quite meet up again exactly the way you want it so you can see i've sort of created a little bridge there which is going to be my cut line and that's where once everything all sets up i'll cut that mold open and open it so i'm going to go ahead and add a little bit more here and you can interchange between the two different styles of mold making so if i just need to thicken up a tiny little area i can go ahead and add a little bit more silicone to my water i've made a huge mess here and again start patting that on just like we did before and i just keep adding layers until i get to a nice thickness that it's going to all hold together with the core casting process the more time you spend kind of on setup and planning things out the more successful you're going to be it just takes a little time to kind of get this initial these initial steps going if you had a big object that you wanted to core form uh you wanted a hollow core you could take that mold and slush cast the wax into it just make a thin shell of wax and make a core that way the only issue with that is that it's hard to tell that your thickness is uniform doing it this way where you pre-make the core you can ensure that your casting is going to be uniformly thick especially if you're really going for a thin walled vessel or something like that something like joanna's pear and bottle of course she just had a bigger circular mold and then the pear could sit down inside of it but anything where uh your glass is sort of conforming to the shape of your core you want to make sure that it's as uniformly thick as possible so that your core doesn't look off center or you end up with an area that doesn't actually fill excuse me so doing it this way where you're pre-casting the core making it advance and then adding the wax around it or adding a bigger mold around that so you can get in there and really see that it's uniformly thick you'll have a lot more success all right so again you know i just keep adding layers uh until it gets to a nice thickness that's usable for me and that i can pour the wax into i'm just going to keep adding that one thing that you can do with these molds is add an extra layer that acts as a locking mechanism uh which i like to do especially for these thin molds that i can't necessarily wrap things around um so one thing you can do is add a little flap to these so that it locks together a little bit better and to do that i just use um a little bit of petroleum jelly because the silicone won't stick to it and i put that on one side of that ridge that i made so not both sides just one side of it so that side has no petroleum jelly this side does and i've colored this with food coloring so i can see it a little bit better uh the woman who taught me this little trick um would use a stick of lipstick but lipstick's expensive um i went to go buy some and i was like whoa i'm just gonna get some vaseline that's much cheaper so putting that on one side of it then i can add in my last layer and go right over the top of the petroleum jelly first on the one side with no petroleum jelly then right over the top of the area with the petroleum jelly covering that all up and i can see the the petroleum jelly the vaseline through there especially since i colored it that's why you want to color it so you actually know where it's at and that'll give you a good sense of where to cut your mold open set this aside and if we go to the cooking show it's done uh here's our mold uh we've added you can see where the petroleum jelly was right there and then all i did was cut next to that petroleum jelly to open it up because it's not going to stick right there i could pull this flap back that's created because of that petroleum jelly where the silicone didn't stick pull that back and then cut through my thickened line and then what that does is create a little locking mechanism so now the mold doesn't fall apart so here's that flap that i just created there's my thicker cut line right in there i'm sorry this is clear i wish this is a different color it's kind of hard to see but this is the thickened line and then open it up and there is my uh interior of the mold there so all that does is it makes sure that it locks together uh so you're not messing with rubber bands and pins and all these kind of business like that it just all locks together itself and you don't need to mess around with anything else

Channel: High Desert Observatory

Views: 762,268

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Id: 6ikF1h2QbM4

Length: 24min 32sec (1472 seconds)

Published: Tue Apr 27 2021