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Cast Marble Effect
Overview - Creating a realistic cast marble effect is possible with Smooth-Cast® 325 liquid plastic. Ure-Fil® 7 is mixed with SC 325 casting resin until the mixture is thick and creamy. This mixture is then simultaneously cast with black pigmented Smooth-Cast® 325 to create the "veining" effect commonly found in marble. Getting the effect you want will take practice and we offer the guidelines below as a step by step outline to get you started.

marbleeffectgrouping_200Materials Needed:

Ure-Fil® 7- lightweight filler will be mixed with Smooth-Cast® 325  resin to help create a marble effect. It gives cured castings a translucent quality similar to marble. Ure-Fil® 7 should be completely free of moisture (refer to Technical Bulletin).

Casting Resin - Smooth-Cast® 325 ColorMatch is recommended because it is a color neutral resin that is ideal for creating castings with color and color effects.

So-Strong® Pigment -  Adding a color to the resin/Ure-Fil® 7 mixture will give the final casting added definition and dimension.

Also required: Rubber Mold; Mold Release Agent; measuring and mixing containers; mixing sticks.

Master Batch:
1 part Smooth-Cast® 325 A:
1 part Smooth-Cast® 325 B:
2 parts Ure-Fil® 7

Veining Batch:
Approximately 5% Part of Master Batch: Color Tint (You can use other SO-Strong® colors besides black to create the vein such as green, blue, red, etc.)

Amount of resin, Ure-Fil® 7 filler and pigment required will vary depending on the size of the mold. You will have to experiment by varying the amounts of resin, Ure-Fil® 7 and pigment used in combination to attain an effect that suits your application. Be cautious not to overload the mixture with pigment or cure inhibition/oozing may occur.

Measurements Used For This Example:
One 7 oz. cup of Smooth-Cast® 325 A
One 7 oz. cup of Smooth-Cast® 325 B
Two 7 oz. cups of Ure-Fil® 7
One drop of SO-Strong® black pigment for veining

Step 1: Apply Release Agent To Rubber Mold

If casting into a urethane rubber mold, prevent resin mixture from sticking to rubber mold with application of a spray mold release agent (Ease Release® 200) into mold cavity and all surfaces that will contact the resin. Brush lightly and follow with second light mist coating. Let dry for 20 minutes.

Step 2: Create Master Batch

Parts A & B are thoroughly pre-mixed. In separate containers dispense 1 part Smooth-Cast® 325 A (yellow container), 1 part Smooth-Cast® 325 B (blue container) and 2 parts Ure-Fil® 7. Thoroughly mix Part B with dispensed amount of Ure-Fil® 7 until a thick consistency is achieved. Dispense material into a clean mixing container. Thoroughly mix Part B/Ure-Fil® 7 mixture with Part A*.

*Note: Smooth-Cast® 325 has a 3 minute working time.

Step 3: Partition Batches

Portion approximately 5% of the Master Batch into a separate container, this is now your Veining Batch. Add a drop of a SO-Strong® color of your choice to the Veining Batch. Color is then blended into the material for 15 seconds.

marbleeffectstep4_200Step 4: Pour Veining Batch Into Master Batch

Colored mixture is then drizzled back and forth over master batch.

Do not mix or disturb at this point.

Step 5: Pour Master Batch Into Mold

Mixture is poured into the mold in a random pattern.

Step 6: Allow Casting To Cure Before Demolding

Material is allowed to cure for at least 20 minutes at room temperature (73°F/23°C). Thin castings will take longer to cure.

Step 7: Demold Casting From Mold

marbleeffectstep7_200Casting is demolded to reveal marble effect. You may lightly polish casting with a wax until the desired luster is attained.



There is a learning curve associated with this technique.  Understand this technique takes practice and will never come out exactly the same way twice.

To achieve a multi colored marble, create a second veining batch of a different color. 

For more defined striations you can add additional filler to the veining batch before drizzling into the master batch.

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