Moldmaking Tutorial: How To Make a Resin Metal Cold Casting

Moldmaking Tutorial: How To Make a Resin Metal Cold Casting

What’s up Everyone? Today im going to show you how to make a cold cast reproductions of this plastic busted of Abraham
Lincoln we’re gonna be using products today from
a company called Smooth-On Our first step is that we are going to secure this plastic model onto a Melanie board using hot glue once the model secure I am going to place this lazy susan underneath the board it will help me rotate the model as I am working with it. Next, we are going to apply ease release 200 which
is a release agent we’re gonna spray a very light
coating onto the surface our model to help facilitate the release of our mold rubber from the model surface For this project I am going to use Dragon Skin 10 very fast its Platinum
silicone from Smooth-On this is a two-part silicone system this
is part A and this is part b wear latex free
gloves when working with silicone latex will inhibit the cure of silicone apart so make sure
your gloves are latex free. I am going to open part A I am going to take a clean stir stick and we are going to stir the contents very thoroughly make sure to scrap the
sides in the bottom as you do this We are going to do the same thing now with B again clean mixing stick stir very thoroughly scraping the sides and
bottom to go. the mix ratio for Dragon Skin 10 very fast is 1 to 1 by volume. So you want to dispense equal amounts of Part A and part B. First we are going to dispense part A into a clean mixing cup. Now for part b I marked the cup with a black line. this is important because both parts
are translucent this will help you keep track of the
different materials you will be working with. Part B is now dispensed. same amount as we did for part A. See how the equal amounts of parts A and B. Now we are going to color our silicone Part B with Smooth-On’s silc pig silicone rubber color system
for this first layer were gonna use the green color pigment. I am going to take this clean popsicle stick and I am going to dip it into the colorant and I am only going use a very tiny amount. Just this amount. to color part B of our silicone system. Now we are going to add Part A to Part B. Using a clean stir stick I’m going to scrape out the
material in to the mixing cup. Now we are going to use Thi-vex. Thi-vex is a thixotropic agent which allows you to thicken the silicone. We are going to use thi-vex every layer of silicone we are going to be working with today. It only takes a small amount to thicken the silicone. Once you have added Thi-Vex to the mixture we’re going to give this a thouro mix. be sure to scrape the sides and bottom as you do this. Now we’re going to use a
brush to apply are silicone material. Note that I have cut the edge this helps to stipple the material onto the surface of our model. Keep brushing the silicone using a short jabbing motion to push the material onto
the surface of my model Here now is our first layer note how thin it is
applied to the model service we want it nice and thin to capture the detail of our model. we are going to allow this first layer to tack up
before we apply our next layer for the next layer we are going to use the Silc Pig yellow following the same steps as we
did before we’re gonna add tiny amount of color using a clean stick. just this amount is enough to color the part B We are going to add thi-vex to this layer and apply this to our model. for this layer we are going to use a simple brush, no stippling needed here. no stippling required here we’re just
gonna apply thickened silicone to apply our second layer. Now for our third layer we are going to use silc pig red again same process we are going to add small amount of colorant using a clean stick
color part B and add your thi-vex. For this layer we want it nice and thick. Now Im going to use actually a popsicle stick to apply the thicken silicone note how thick it is on this layer. We’re going to use this on our final coat of mold rubber onto our model. Here is our final layer. of thicken silicone applied to our model. Note that we create a flange around the model around the base of the model. We are now going to trim off the excess material on the base and this is important because you want
this to register to our sport shall so having a nice clean edge helps with
the registration we’re going to trim off all four sides now also to assist registration I am going to trim off the front two edges. Giving it an angle cut. Again this will assist with putting a registration in our support shell For our support shell material we are going to use plaster bandages this is gypsum plaster bandages available from smooth-on. we are also going to use the sonite wax. The first step is that we are going apply sonite wax which is paste wax that we are going to apply on to our mold rubber using a brush. the wax a smooth on the
surface very easily make sure you cover all areas of the mold rubber including the flange and off the base. Next we are going to prepare are plaster bandages I like to use 4-ply plaster
bandages in other words Im going to fold this role 4 times I like to use a length of about 10 inches so this is are first layer of are plaster bandage taking a pair of scissors i’m going to trim it up. and here is your 4-ply bandage strip. now we’re gonna did the strap in to water remove the excess and apply it directly
onto our mold rubber pressing the plaster to the service on the rubber we want the plaster
bandage to conform to the shape of the rubber I’m gonna repeat this process for the
entire first half of my support shell so im going to dip the plaster into the water and removing excess water by squeezing the
plaster bandage and then applying the bandage onto the surface of my mold rubber to create my support shell make sure to extend the support shell
at least a half an inch or more beyond the rubbers edge. So that the rubber can sit well in the plaster shell. So here now is the completed first half up shell
next im going to apply sonite wax again to the edge of the plaster. what we are going to do is going to apply the second half and its going to overlap the first half of the shell So I want to apply ample sonite wax to the edge to prevent that too has from locking
into each other be sure to apply even coating of the wax all along edge of the support shell. now we are going to repeat this process to create the second half of our support shell. Again dipping the plaster into the water removing the excess moisture from the
plaster bandage and then applying it. We are going to overlap the edge here as we apply the second half of plaster to the model. Here now is the completed shell note how it overlaps the second half. Once the plaster is fully cured we will be able to demold them be careful as you move this me take a
little bit of work on the on the edging between the two plaster shells. but once you get that going it is easy to remove here is the shell removed now we’re going to apply a little baby
powder to the mold rubber and the reason we do this is because we want to facilitate the removal of our glove mold from our model Adding a little bit of baby powder to the surface. basically helps remove the tension from
the surface of the mold rubber. and it make it easier to peel back. Now we are going to remove our glove mold from our model to extract the
original plastic model from the mold rubber. Take your time when you do this. you just want to carefully peel the mold rubber away. To extract the model. And here we go with the original model removed I will now recept the mold rubber back into the support shell note how the mold rubber sits perfectly
registered within the supposed shell next I’m going to take some rubber bands
to secure the two halves of my support shell. to prevent the two halves from coming apart. and i’m taking a deli Cup and im going to put my support shall inside of it. This will help create a level surface so I can pour my resin in the mold rubber and now my mold rubber is ready for casting. For our casting material we are going to use Smooth-Cast 325 this is a 2 part polyurethane system this is Part A and this is part B. Now when working with this polyurethane system you want to shake the material well before
using Im going to shake part A similarly were going to shake well before using with part b We are going to first start with part b. dispense into a 2 oz container next we’re going to use so strong colorant this is a liquid urethane colorant system from smooth-on it only takes a few drops of this coloring system to color part b taking a clean popsicle stick we’re
going to stir the colorant into part b color the material next we’re going is bronze powder now this is real
metal powder that we’re going to dispense into a 2 oz container now we’re going to dispense part a now you should have equal amounts of part a and part b and metal powder. now we’re going to mix part a and part B into clean mixing cup taking clean popsicle stick wanna give
it a good stir be sure to scrape the sides and the
bottom as you go give it a stir for about 30 seconds and then were going to start pouring in the metal powder into the mixture once I resin is ready to pour we are going to pour small amount in first into are mold rubber initially and
we’re gonna slush cast in other words we’re going to pick up the entire system and slur it around
this helps push the resin to all the detail of my
mold rubber we’re going to continue this process and
continue to swirl the material around so that we get nice
even coverage throughout the entire interior of our mold rubber. next were going to mix up some additional
resin coloring it with so strong black and we’re going to fill in the remainder of the cavity with additional resin to top it off. After allowing the resin to cure for about 10-15 minutes it ready to demold again we are going to be careful in removing the mold rubber just work the mold rubber up and slowly remove the rubber. from the model to extract our
reproduction next were gonna apply a little bit
isopropyl alcohol to the entire surface of our casting the reason we do this is to soften the plastic surface a little bit and prepare it for polishing. Next we are going to use some steel wool polish our casting and allow for that
metal to really shine through we are then going to apply some black shoe polish to our casting to further enhance the detail of our model and there you have it a cold cast reproduction our original
plastic metal powder looks incredible and it has the look
and feel of real model

17 thoughts on “Moldmaking Tutorial: How To Make a Resin Metal Cold Casting

  1. Well done video! Question here; if you have to end up doing a piece mold in resin, you'd probably end up gluing the pieces together after cleaning up the seams, but what would you use to fill in seam channels or divots? I'm wondering about keeping the color consistent with the other pieces and with repairs. Has this been an issue for you? Yes, you measure and all, but still, there can be variants. I haven't tried a complete glove mold yet, but looking forward to it. Thanks for posting!

  2. To get a bronze finish rather than a resinous finish; dust the inside of the mould with the bronze powder, gently shake out the surplus and then pour the resin/bronze mix. This will give a true metallic finish.

  3. Hi, I wonder how coating the outside of silicon mold with baby powder can help releasing the inside of the mold ?

  4. thanks for the tutorial, it saves a lot of silicon, compared to other methods i've seen.
    I didn't understand why you had to add the color to the silicon if it's only for making the cast any. why not just live it in its natural color?

  5. Is there a way to give it a polished bronze look, which is more reddish/copper and yellowish/brassy than it is brown?

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