DIY silicone - can the positive be soap?

[dixiedragon]

I have a milky way mold that I LOVE the shape of - the scroll hearts mold. But it's been discontinued and mine is cracking. I want to make a 6 or so cavity silicone version. I've found places to buy the silicone online - what can I pour in my mold to make the positive? Soap? Parafin? Beeswax? Soy wax? Soapwise, I was thinking a 0 superfat coconut soap, so it would be very hard, then shred it for laundry soap.

Frankly, if anybody can recommend someone, I'd be happy to pay somebody to make this for me. Mail them my milky way mold and let them make it. Because I figure that by the time I order silicone, pay for it + shipping, and screw this up a few times, I'll save money doing it that way.

 

[Navaria]

What about that plaster stuff you can buy to put kids' handprints in? That should make a good positive I would think.

 

[mzimm]

Yes, dixiedragon, what Navaria points out would work. There are also many molding clays you can pick up from the crafts aisles at Michaels, A.C.Moore, or even Walmart, that air dry or bake dry.

But I think soap would work well, too, as long as it's poured thick enough and allowed to dry hard. That silicone is some pretty neat stuff, and will have no problem picking up every detail your soap provides. Using soap would be your cheapest option, something to consider, as that silicone is not cheap as you pointed out.

 

[penelopejane]

There are quite a few videos on this online. Google how to make a silicone mold. Using soap you would have to make sure the surface was perfect.

 

[dixiedragon]

I've been googling but all of the videos I've found show using some kind of object - such as a shell or a figurine. They don't say what to do if you have a mold you want to duplicate. I'm leaning towards paraffin wax right now.

 

[galaxyMLP]

I would say you want something non-porous. I don't think plaster would work well unless you coat it first in something.

Soap should work ok but, wax would work very well. I've made a silicone mold of little plastic green army men before with the silicone and dish soap tutorial. Tip: let it dry outside! It releases what smells like concentrated vinegar as it cures. The only thing about using soap as a mold positive is that with the water/dish soap it will soften the details. You'd want something waterproof. I really do think paraffin wax would work great.

I've never used the mold putty they sell at craft stores so I can't weigh in on how those work. But, they probably work better than the 100%silicone from a tube. This is the mold I made:



It's dirty right now (sorry). It was more difficult to make than it looked! Next time, I would get a flat, non-stick surface and lay the mold positive on that. Then I would put a box or container on it (somehow!) to get an even bottom. This would mean I would get even cavities and bottoms so it is easy to pour. As it is, I can't use like 3 of the cavities because they're too shallow or are slanted and don't keep the soap.

 

[dillsandwitch]

I have used plaster of paris and then just painted it using poster paint. Works really well. When applying the silicone first use a brush to coat your castings then once pouring, pour from the side and let it flow where it wants to fill the mould spaces. I would also sugest to hot glue the casting to the box you use. I made a box outta lego and hot glued it to a chopping board. ut all came off Really easy too. HTH

 

[penelopejane]

I have used plaster of paris and then just painted it using poster paint. Works really well. When applying the silicone first use a brush to coat your castings then once pouring, pour from the side and let it flow where it wants to fill the mould spaces. I would also sugest to hot glue the casting to the box you use. I made a box outta lego and hot glued it to a chopping board. ut all came off Really easy too. HTH

Dillsandwitch is spot on:

[ame]https://www.youtube.com/watch?v=SiNaDAtyTWU[/ame]

 

[dixiedragon]

So I've been googling around trying to find some local folks making silicone molds. No luck there - but I did find a local silicone manufacturer! So I'll give them a call, place a teensy order and try this myself. I'm going to make my positive from paraffin wax (fairly cheap, I'll use a coupon for 40% off at Hobby Lobby) and I'll get some cheapo plastic drawer dividers to be the mold. They have a flat bottom.

I wonder if Sculpy (oven baked polymer clay) would work? If I could find a person with good carving/sculpting skills, maybe I'll start making silicone molds for etsy.

 

[earlene]

Once you have done this, please post your results with using the paraffin wax as your positive. I have been wanting to duplicate some DC'd plastic molds I have for the same reason. I have paraffin wax for my paraffin wax bath (prescribed for my hands by my physical therapist after surgery on my finger and for my Dupuytren's. My concern would be temperature, as paraffin begins to melt at 99F, so I wouldn't want to use it on a hot day, since I'd have to do this outdoors.

Last winter I bought a package of the Crayola brand modeling clay to use to make the castings from the soap cavities, but that's as far as I got. I have yet to take the next step, making a decision on which silicone molding material to use, for example.

I have made individual silicone molds using 100% silicone caulking and cornstarch and a little bit of acrylic paint to color it. In fact that's the process I used to make the mold for my Fish soap that I later felted and photographed and use as my avatar. The positive was a decorative acrylic (I am guessing it is acrylic, as I didn't actually buy it myself, but that's what it looks like to me) fish.

I have also made some molds using Naptha solvent, which has some pretty horrendous fumes but makes the silicone much more liquid-like and works pretty well for painting it onto a surface. However the odor takes a long time to go away and I don't much like that process. Every time I made these molds I did it outside because good ventilation is important even if it's only silicone caulking and cornstarch. And the odor of the silicone remains for several days as well, so I left those molds outside for a few days, too. The odor of the silicone with Naptha solvent took even longer to go away, so those were relegated to the garage for some time.

What started me out on this path, besides wanting to replace those deteriorating plastic molds, was also that I wanted some personalized molds for family members. I am constantly on the lookout for the perfect item to use to make a soap mold. For my granddaugter that is easy enough, but for my grandson finding some boy/mannish item that is not to intricate in its design (and the right size for soap) is a bit more challenging.

 

[earlene]

Dillsandwitch is spot on:

https://www.youtube.com/watch?v=SiNaDAtyTWU

Oh, I like that. I might just go the plaster of Paris route myself and forego the modeling clay idea. It looks much easier to use. After seeing the above video I am not even sure what I had in mind when I bought the modeling clay.

Oh, I think I remember now. Maybe it was to help make the second side for a two-piece mold, which I also want to make.

 

[cmzaha]

A non-hardening clay works very well for pouring against. When we still had our Formliner Company, many of our molds were carved out of clay. We melted it down, and poured it out in a 8-10 foot base so our sculptor could sculpt out the design. After the design was made we had to do 2 urethane pours to make an actual working mold. If you melt the clay and pour it into the mold you will end up with the positive, which you then use to pour your silicone over to create a negative mold. Nice part of using non-hardening clay is, you can re-use the clay

 

[Spice]

I have a milky way mold that I LOVE the shape of - the scroll hearts mold. But it's been discontinued and mine is cracking. I want to make a 6 or so cavity silicone version. I've found places to buy the silicone online - what can I pour in my mold to make the positive? Soap? Parafin? Beeswax? Soy wax? Soapwise, I was thinking a 0 superfat coconut soap, so it would be very hard, then shred it for laundry soap.

Frankly, if anybody can recommend someone, I'd be happy to pay somebody to make this for me. Mail them my milky way mold and let them make it. Because I figure that by the time I order silicone, pay for it + shipping, and screw this up a few times, I'll save money doing it that way.

what do you mean by "Positive"?

 

[Dorymae]

what do you mean by "Positive"?

The positive is the part you will use to create the mold. For example the negative is the mold itself, if she tried to use it as a positive she would end up with soap shaped silicone. She does not want soap shaped silicone she wants a mold that will make the soap shapes, so she needs a positive - the soap shapes themselves to make the mold that will allow soap shapes to be made.

 

[dixiedragon]

What Dory said. For example, if I want shell-shaped soap, I would use a shell as the positive. The negative would be the impression of the shell in the silicone.

I emailed the silicone people and they said paraffin wax would be a great negative, so I'm going to use that.

 

[doriettefarm]

dixie - did you buy paraffin wax yet? Hold off if you haven't because I've got a huge chunk that could be used for this experiment. Meant to bring it last time we met for dinner but brain-farted!

 

[dixiedragon]

dixie - did you buy paraffin wax yet? Hold off if you haven't because I've got a huge chunk that could be used for this experiment. Meant to bring it last time we met for dinner but brain-farted!

I remember! Let's pick a Sat or Sun to get together and do this!

 

[Spice]

What Dory said. For example, if I want shell-shaped soap, I would use a shell as the positive. The negative would be the impression of the shell in the silicone.

I emailed the silicone people and they said paraffin wax would be a great negative, so I'm going to use that.

I have been so negative in the past 2 months that I am just now getting back to the forum. So sorry. I see I missed a lot. :cry: