EASY! HOW TO MAKE a TWO PIECE SILICONE RUBBER MOLD


these videos are brought to you by Hobby Silicone.com and Jon Neill Quickly I’ll show you how to
make a two-part mold from this hand sculpture that I made in wax. You’ll need
a sharpie marker and what I like to do is try and figure out where my seam line
will be. I will draw a line around the middle side of the sculpture to show where the clay seam will meet on the sides. You do not need a lot of supplies
to make this mold. You will need some water base white clay to make the clay wall as well as a wooden board or a cafeteria tray will work just as well -use some cellophane to cover the backside of your sculpture. The side that
will be exposed to the clay. The cellophane will protect the sculpture or object from losing important
details filled up when you’re making your mold. To make this mold you’ll need
a handful of materials such as a clay knife or some kind of kitchen knife
or butter knife and a metal kidney it’s flexible. Most importantly a couple
of brushes that are flat, not round shaped. A big 1″ flat brush and a small 1/4″ sized brush.The brushes will help you get the perfect edge against your sculpture. You will need some water
and a bag of pottery “white” clay it’s great clay with a very smooth consistency and it’s very inexpensive. You can use it over and over for your molds if you take good care of it. Now start packing the clay around your sculpture. The idea here is that you take your clay and get it all the way up to that black line that I drew with my sharpie marker around the sculpture. You’re probably thinking
“Why are we doing this, it doesn’t make any sense?” “Why do we want
one side clay?” Well the idea is is that we are going to build a box around the sculpture and the clay wall
and fill the top side with silicone. The clay is representing the second half of the mold. So if we make this side look nice and
pretty, then that means that our molds probably going to fit together very well…
now here’s a trick you use – These flat brushes, you will wash away
this messy clay edge. You want to create a nice right angle shape against the sculpture. You want the clay to meet up against the
sculpture nice and crisp like a shape like the letter L. When the edge of the sculpture meets the edge of the clay and
a nice hard edge that means that your seam line, after you make your silicone mold, should be almost invisible. The clay “layup” (clay wall) process usually takes about an hour for your first time. You may consider that might take up to two hours
if you also include your prep time to do something about this size, any bigger
maybe three hours. I got some water clay on my actual
sculpture. There’s no details to worry about so I can carefully wipe it off
with a paper towel. I’m adding my pour spout at the wrist, making it giant.
Usually I make the pour spout very small. Now I’m using the end of my Sharpie
to make registration marks aka keys. So- a real quick, crude way of doing it, I do it fairly close to the sculpture. Now I’m just cutting the edge off of the clay because I’m going to put foam core up- against the sides. Then I’m going to
wash it down a little bit. I have enough pieces cut here for each side of the
mold as well as my glue gun and my hot glue sticks. I’m just setting them up on
the side and then gluing them across, leaving one edge of the foam core right
at the corner. As you see, one side overlaps and the other side is
flush with the edge. It’s so easy even a kid can do it! Hobbysilicone.com sells small amounts of their silicone such as their Mold Master 2125 2LB
and 5LB kits with green catalyst. I’m using a 10 pound kit of 2125
silicone for this project The cups on the scale, I tear out the
weight so now it’s back at zero again. Now I can add my silicone into the
cup. There is 500 grams of silicone, I
need to tear off the scale again to 0 and weigh out- 10% of the catalyst which would be 50
grams. Stirring the catalyst and silicone together has to be an accurate process… The silicon is done being mixed when
it is an even green color. The trick- to get bubbles out of your silicone is by
doing what’s called a “high pour”. This is- when you pour a very thin stream of
silicone into your mold, up to the line that you made with your Sharpie. After
the silicone is cured- peel off the sides and then cut away any
extra silicone that might have bled out onto your sculpture. Carefully remove the
white clay from your sculpture and take your flat brushes and use a wet brush
and wash away the clay that’s right against your sculpture so you don’t damage it. Once this side of the sculpture is clean, take vaseline and a clean flat
brush and apply Vaseline to the silicone flange- around your mold. This will make sure
that the parts don’t fuse together. When you pour your second half, glue your foam
core walls into place and fill with- silicone.Once the silicone cures you’re
able to de-mold it and open your mold. Using your exacto knife, cut in your pour
spout and now we’re ready to pour some- resin!! You will need cups, a brush, tongue depressors, baby powder and latex gloves. Brush them off with baby powder this
acts as a great mold release. Blow out or tap out the remaining powder out of the
mold. The MPK 70 resin comes in part A and B, mix the two in an even mix and pour
and fill your mold. When it cures it’ll turn a white color. If you want your
resin another color you can purchase various tints. Tap the mold on the side
to get out the air bubbles until the resin- starts to cure. Before casting you can
tape your mold together or use rubber- bands, put 2 boards together on both sides of the mold and rubberband it together. I used tape and you can remove it to open it and pull
out your resin piece. There’s barely any seen and I just use a
tape to hold the mold together. That’s how you make a two-piece mold!
In the description below the video I have a list of materials which you’ll need to do this project and can purchase through the amazon links provided. Order today!

100 Replies to “EASY! HOW TO MAKE a TWO PIECE SILICONE RUBBER MOLD”

  1. No, White clay is water based clay that air dries. Pottery clay. Thats why you see me using water with brushes in the film. I would only use oil based clay like or better yet, klean clay for doing a clay lay up against a intricate object where the water from the clay would rust or damage it. An example would be against a knife or a computer. You keep the water based clay slightly moist by spritzing it with water occasionally and covering it with plastic wrap overnight. I hope that helps!

  2. Very informative. I am looking to make and cast my first mold. I was curious what cost investment I would have to mold and then cast 3 or 4 softball sized molds, using the method you laid out in this video?

  3. Hi Justin,
    Depending on the size of the object inside your softball sized mold, that could effect the amount of silicone you use. I am speculating based on what you said, you need about a gallon of silicone plus the supplies I mention in the video. Hobby silicone ( MPK Enterprises) has everything you need to make your first mold. Call 714-899-7963 and ask for Mike – Tell him you saw this video and he can answer all your specific questions on pricing and shipping. Good Luck!

  4. doesn't the clay dry out so you cant re use it again? how do you keep the clay this flexible over and over again? 
    if you have a symmetric piece, like a ball, can you poor silicole for the bottom part instead of using the clay, let it dry, put vaseline one it and then poor the second part?

  5. WONDERFUL video, very direct and educational, hard to find videos this well done and informative on youtube most of the time, im wondering though, would you recommend the same products and process for smaller/higher detailed pieces? such as small figures/doll heads/miniatures/etc?

  6. Is it possible that I can send you my model and have you cast it for me? If so, what would be your cost? I have tried this unsuccessfully many times and cannot get it right.

  7. Hey Jon, thanks for the video, its very helpful. Was wondering if you had any advice on how to create a mould from a piece of meat e.g. chicken breast? Would you need to wrap the meat up in plastic wrap (but would this not create creases)? Would it matter than the meat is soft? Thanks so much, sorry for the strange question. 

  8. Where could I purchase the silicone you use? I really want to cast a bunch of resin figures for my gramma's "Santa's village"

  9. I have several books on how to do this, but they never really made any sense until I watched this.  THANKS for the vid- it is great!

  10. If you were doing this on, say, a painted toy gun, would the clay you use here damage the gun or remove the paint in any way? I want to create a mold of a toy gun, but I don't want to ruin the toy in the process.

  11. When you are molding against something that could potentially get ruined. Especially with water based material which could remove acrylic or water based material, or even rust metals, use a clay called Klean Clay.  You can find this through Hobby Silicone or Reynolds Advanced Materials.

  12. great tutorial! Now I can begin casting the doll I've been making! Gotta get a drill and a dremel though, which I'm not too excited about having to use.

  13. Nice video – very thorough, love the time lapse as it shows all steps in process.  Often, videos that start and stop miss some particular step that is what I'm missing in my work.  Also like that materials and tools are "every day" and inexpensive.

  14. Thank you for putting this in simple steps. I want to cast parts for my model cars and this seems to be the one to follow. Cheers

  15. i've watched a bajillion of these videos over that last couple of years, and yours is pretty good. 

    i don't think the moulding process would be the challenging part for me and the simple scults i have planned, rather the finish is my concern and hoped you had an idea/suggestion. i own a trophy shop and wanted to make some custom trophy toppers. i think resin would work fine, but i don't know how to get that 'chrome' look trophy toppers have. any thoughts?

  16. Would this style of molding work for a cured polymer sculpt?  Also, would you recommend not painting the polymer clay sculpt until after creating the mold, or is painting it before hand okay?  Thanks!  (great video too).

  17. So if I wanted to make a mold of a plastic model car (body only), being that I wouldn't want a line down the middle of the car would I basically bury the shell upside down all the way to the bottom of the car then mold the under side first (side A) then remove the clay and mold the outer shell (side B)? But how would I make the resin cast? Could I pour the resin into side B then press side A into it and tape together? Or how would it work? Hope I was clear and some help would be appreciated thanks and good vid.

  18. Hello, I have a question about the weigh of the resin.
    I want to make ice tips for a trident, but heard from a friend, that resin will be too heavy for a staff. Do you know of anything lighter and clear I can cast with?
    Thank you so much! 😀

  19. I'm looking to cast some polymer clay sculpted teeth and was wondering if a one piece mold or a two piece mold would be better. Now that I think about maybe I could do a one piece mold but when I sculpt the teeth make the bottom edge longer so I could sand it into the shape I want. Anyways suggestions would help and if my idea seems like it could work please tell me so 🙂 thank you for your time

  20. Hey! I have a (propably quite dumb) question: I've seen many people casting things they only need once. Why don't you just use the original model for that? Wouldn't that be much less work? Or has it something to do with the material? I just don't get it….

  21. Decent video but you absolutely skipped over all the details about the pour spout. You mention it…barely…but it's so critical that it deserves a lot more discussion.

  22. How would you do this on a 24in super sculpey clay sculpture that is not baked. I don't want to cook it cus I want to reuse the armature. Please help

  23. Love your simplicity:) I sculpt with polymer clay. I am trying to make several  skeleton heads that I can sculpt over so I dont have to recreate the whole head each time. It will be baked at 275 for 20 Min. Will resin work for this? By the way I think I have a model head you made…helps me .   [email protected] 

  24. I am going to make resin toys using super sculpey and this stuff from Amazon for the moulds. http://www.amazon.co.uk/Polycraft-GP-3481F-Silicone-Making-Rubber/dp/B00261ZKLK#customerReviews Would this be okay do you think for your methods? Thanks mate!

  25. 'Baby powder' is not a release agent! When casting without vacuum chambers or pressure pots & even when gates/vents are in place, it can be used as a mechanical agent to break the surface tension on the negative or internal positive core/matrix core, so the casting material will flow correctly into & over the negative &/or core to fill voids, air pockets, heavy undercuts, thin forms, etc. However, 'baby powder' WILL deterioate your negatives detail & often the surface of your casting. If you genuinely believe 'baby powder' to be a "great" release agent, go ahead, try casting silicon into silicon, or urethane into urethane, or plaster into plaster, or utethane into plaster, or plaster into GRP, or urethane into GRP, or GRP into GRP, etc, with baby powder as your release agent & enjoy your ruined work. Stop dishing out false info, as you end up doing more harm than good.

  26. Hello,Jonathan 
    Thanks for your video! 
    I should make a mold for my art work now, but i've never made a mold in my life.
    My mold is for 2 spheres connected in one shape.
    Almost like an hourglass, than it is supposed to have a space to put something inside. i'm wondering that you have a solution for that! <3

  27. Great video. I've watched a few two-piece mold making tutorials, but this is the only one that makes me confident that I can do it.

  28. I have made a custom shaped hard wood archery grip that I use for Olympic archery (FITA) . I want to make a mold so I can make a copy for my backup bow. What material (how hard?) should I use for the casting resin? The grip must not give, so the strength need to be similar to a plastic screw driver handle.

  29. i like the way you sound haha. it sounds engerly sleepy. anyway thank you for the great, simple but critical tip

  30. Great tutorial! Will helps much. I just have one question: what clay did you use to sculpt the hand and what did you seal it with?

  31. Will you please give a supply list and possible retailers for supplies? My son wants to start this kind of work, but I have no idea what or where to buy the materials.

  32. Let's say I want to make a helmet like one from star wars. I'm putting in a special powder that when heated becomes plastic. How would I make a mold that I can pour in the powder and when it solidifies, I can remove it, and it be hollow so I can put it on

  33. Very nice video… I am building a wooden model… will Vaseline do the trick, or should I clear coat the model first.. It does have primer on it now… I was now sure if coating Vaseline on the primer is enough/

    mike

  34. awesome tutorial. I have a lovely resin cherub…but I want to make a mold to make a concrete copy for my garden…I'm just unsure how to approach the wings..it seems like a two part mold is not possible. any ideas on how I could make this mold??

  35. hi Jonathan. great video. Ive watched several of these now and think I'm getting the hang of it but theres so many silicones and resins, I'm not sure what to get as funds are tightish so don't want to go mad. I'm just getting into sculpting and have nearly finished my first piece of yoda. if your on instagram I'm @jayclay74 if you want to have a look. I'm going to have to do a 2 piece due to his ears. would love any advice or tips to put me in the right direction buddy (if you have time) thanks Jonathan

  36. What happen to the piece of plastic wrap you had on the bottom of the hand? It was there one minute, then it was gone? What happen to it? Thank you Mary

  37. Hello, I am impressed of you work! But I have a question, wich is your favoroute wax? Because I wanted to sculp small very detailed figures and for that I need a strong wax..

  38. Baby powder isn't a release. It does the opposite. It reduces surface tension on your mold and helps draw the resin in to every nook and cranny.

  39. Anyone know of a fill material I can use that isn't super stiff so I can slightly move/reposition the copy?

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