Silicone Caulk Mold Tutorial
- Thread starter Kwally89
- Start date
jazzygeoffery
Well-Known Member
I'm new to molding, and i know this tutorial is old, but how would you go about making the cast of the mask an even thickness, and not flat on the inside.
JBomm
Active Member
He used slush casting. I've never done it so I really can't explain it, but there are tons of videos showing the process.
exoray
Master Member
I know the thread is old, but...
Just can't follow this...
Local Home Depot sells 12 count case of 9.8oz tubes of GE 1 for $60ish, that is still short of a gallon...
I can get 5 gallons of house brand 'proper' molding silicone for $300 locally or $60 gallon, it's actually cheaper then caulk...
The caulk idea is OK is for small molds or a quickie, but I don't really see any savings in the end...
CB2001
Master Member
Nice. This is a pretty good tutorial.
There's also a couple of others sort of similar to this one over at Instructables. I figured I'd share them with you, in case you want to experiment with these methods too.
How To Make Your Own Sugru Substitute
http://www.instructables.com/id/Make-a-silicone-mold-from-common-household-materia/
There's also a couple of others sort of similar to this one over at Instructables. I figured I'd share them with you, in case you want to experiment with these methods too.
How To Make Your Own Sugru Substitute
http://www.instructables.com/id/Make-a-silicone-mold-from-common-household-materia/
this actually works better with a tiny bit of light corn syrup (like 1 part corn syrup to 10-15 parts silicon caulk)
the corn starch actually makes the silicon harder from what i've tested. Corn syrup causes it to cure just as well, and keeps it softer and pliable.
MrGzilla
Well-Known Member
i used a relese agent and it still didnt come off of my halo helmet. im still scraping and picking sillicone off of it and sanding it back down, im going to have to repaint it and replace the visor when i get all the stuff off of it :cry
Mr Fett
Sr Member
I've been inside a professional prop shop where probably 90% of the silicone molds there were made from silicone caulk mixed with acrylic paint. Only the small detail piece molds were the "theatrical grade" silicone. They've been running pulls out of the caulk / paint molds for years so it obviously works well.
I also was talking with another guy I know a couple weeks ago who graduated from a well respected art college 10 years ago who also told me the silicone caulk / paint mix molds were what they were taught there, as well.
I also was talking with another guy I know a couple weeks ago who graduated from a well respected art college 10 years ago who also told me the silicone caulk / paint mix molds were what they were taught there, as well.
I've just tried this and it worked pretty good, eventually.
I had a small part I wanted to replicate and thought of this thread. And I had some old tubes of silicone laying around. So white acrylic paint and glycerin was added to soapy water and some silicone was squirted into it.
It made a nice blob which was smeared on the part. The piece was made of a waxy feeling plastic so I wasn't too worried about it sticking.
However, after a few hours it was still sticky to touch. I squirted a bead onto paper and it didn't dry either. Obviously the silicone had gone bad.
FFFFUUUUUUUUUUU....!!
So after I cleaned off the part it was off to the store.
Then I made the same mistake as the OP. After looking at several clears I bought a tube of white. It wasn't noticed until it was squirted out. Now I had white silicone in white water.
This time I also forgot the soap so my hands were covered with silicone.
FFFUUUUU..!
After using many paper towels it was cleaned off.
But when I poured out the water the bits of silicone remaining were already set! I touched the piece and it felt dry as well. I left it for several hours anyway, and then it peeled off easily. However the thread pattern wasn't clean. So I made another mold.
This time I put dish soap on my hands and let it dry. This is a trick used in automotive work. Very little silicone stuck to my fingers, even though I worked it in and shaped it better.
I made the copy with fiberglass and resin. Some baby powder was added to resin to thicken it then it was smeared into the thread pattern. Then cloth was added.
When it cured a bit of sanding cleaned it up. The threads screwed right in and sealed.
So what is it anyway? It's the nose piece for this.
I combined a used gasmask with some welding goggles. Something like this may cost 500 bucks new. Mine was close to free.
I wanted to try pumping low pressure air into the nose to defog the lens and help cool it down in summer, but didn't want to damage the original nosepiece.
[ I also read that tube silicone could be thinned with paint thinner or Xylene. I tried xylene, and it became pourable, and still set normally. It captured some fine detail on a coin, but was still not as thin as a commercial product. It would require a lot of thinner. Perhaps twice the silicone by volume.]
For projects like this the silicone caulk is ideal. I used about 1/20th of a 5 dollar tube. The rest will last for years, or can be used as caulk.
I had a small part I wanted to replicate and thought of this thread. And I had some old tubes of silicone laying around. So white acrylic paint and glycerin was added to soapy water and some silicone was squirted into it.
It made a nice blob which was smeared on the part. The piece was made of a waxy feeling plastic so I wasn't too worried about it sticking.
However, after a few hours it was still sticky to touch. I squirted a bead onto paper and it didn't dry either. Obviously the silicone had gone bad.
FFFFUUUUUUUUUUU....!!
So after I cleaned off the part it was off to the store.
Then I made the same mistake as the OP. After looking at several clears I bought a tube of white. It wasn't noticed until it was squirted out. Now I had white silicone in white water.
This time I also forgot the soap so my hands were covered with silicone.
FFFUUUUU..!
After using many paper towels it was cleaned off.
But when I poured out the water the bits of silicone remaining were already set! I touched the piece and it felt dry as well. I left it for several hours anyway, and then it peeled off easily. However the thread pattern wasn't clean. So I made another mold.
This time I put dish soap on my hands and let it dry. This is a trick used in automotive work. Very little silicone stuck to my fingers, even though I worked it in and shaped it better.
I made the copy with fiberglass and resin. Some baby powder was added to resin to thicken it then it was smeared into the thread pattern. Then cloth was added.
When it cured a bit of sanding cleaned it up. The threads screwed right in and sealed.
So what is it anyway? It's the nose piece for this.
I combined a used gasmask with some welding goggles. Something like this may cost 500 bucks new. Mine was close to free.
I wanted to try pumping low pressure air into the nose to defog the lens and help cool it down in summer, but didn't want to damage the original nosepiece.
[ I also read that tube silicone could be thinned with paint thinner or Xylene. I tried xylene, and it became pourable, and still set normally. It captured some fine detail on a coin, but was still not as thin as a commercial product. It would require a lot of thinner. Perhaps twice the silicone by volume.]
For projects like this the silicone caulk is ideal. I used about 1/20th of a 5 dollar tube. The rest will last for years, or can be used as caulk.
Jordonatron
New Member
I Have to admit, I work at a hardware store and am picking this stuff up dirt cheap ALL the time. And I have been meaning to try this silicone mould idea for ages (I thought I was so clever, I thought it up all by myself 
) Good to see this thread, I am now very eager to try it for real!
But the few experiences I have had with expanding foam- Expanding foam will expand to 3-4 times its original volume. If you fill a cup or bowl up with the foam, and work it a bit, it will decrease in volume but turn into more of a paste. You have to work fast because the paste sets more quickly than the foam because of the air bubbles. but it will set alot harder and is alot neater as a finished product.
Also petroleum jelly =win. I always keep a tube of vaseline with my mould making stuff
) Good to see this thread, I am now very eager to try it for real! But the few experiences I have had with expanding foam- Expanding foam will expand to 3-4 times its original volume. If you fill a cup or bowl up with the foam, and work it a bit, it will decrease in volume but turn into more of a paste. You have to work fast because the paste sets more quickly than the foam because of the air bubbles. but it will set alot harder and is alot neater as a finished product.
Also petroleum jelly =win. I always keep a tube of vaseline with my mould making stuff
MadMike
Well-Known Member
Why not both?
I made this wax-grenade with a caulk silicone mold (actually not following this tutorial here, but just smearing the silicone onto the master). After I pulled some wax-copies, I tried some other materials, including caulk silicone and expanding foam. The foam copy came out without any kind of mold release, and, keeping in mind that the mold was only held together with some tape, was in pretty darn good shape (unfortunately, I demolded it too early, so the copy wasn't perfect).
The silicone copy on the other hand was more or less a proof of concept. As silicone wants to stick to silicone AND is not easy to paint, I tried to kill two birds with one stone and brushed some graphite powder into the mold to release it from the mold and prime it for further painting.
While priming and releasing worked out great, the copy itself didn't turn out that good, as my method wasn't the best. I just pushed the silicone into the mold using the...I actually have absolutely no idea how that thing is called in English, cartridge gun? You know, that thing you use to push the silicone out of the cartridge. This trapped some air in the mold (see first picture) and didn't get every single detail (second picture). But with some pratice, another type of mold and/or "brushing" the silicone into the mold using popsicle sticks or something like that, it should work just fine.
It should be noted though that the silicone seems to shrink over time; you can clearly see the silicone copy is smaller than both the wax- and the expanding foam copy.
Oh, and btw, caulk silicone molds (at least the silicone I was using) can also handle higher temperatures, for a short time. I was able to pull some keyrings in such a mold, using molten pewter.
