Determining Shore Hardness of Rubbers & Plastics

Shore Hardness is the resistance a material has to indentation. Determining a materials Shore Hardness requires the use of a durometer, which is a device that measures the depth of an indentation in the material by creating force through a presser foot.

In order for people to have a point of reference on how hard a material is different shore hardness scales have been created. There are 12 different Shore Hardness scales depending on the type of material that is being measured.

When dealing with rubbers and plastics two scales are used. The A Shore Hardness scale is used to measure flexible rubbers commonly used in molds. Hard rubbers, semi-rigid plastics and hard plastics are measured using the D Shore Hardness Scale.

Both of these scales have ranges from 0-100. The lower the Shore Hardness is on the scale the softer and more flexible the material will be. As you increase upwards on the scale materials become stiffer and less flexible.

When selecting a rubber or plastic to use for your mold making needs there are a couple of things that should be taken into consideration.

How delicate is the item that you’re molding. 

If you’re making a mold of an item that has sharp undercuts, thin parts or protrusions it is recommended to use a material that provides greater flexibility and stretches easily. This will insure that you’re able to extract your model from the mold without it breaking.

How much detail is needed for your project.

When using rubbers and plastics detail is directly related to the hardness of the material that you’re using. The harder a material is the greater casting detail it will provide. For example, if you were making a mold for a stone back splash you would want to use a harder material to pick up textural detail within the rocks.

Abrasion Resistance

Abrasion resistance refers to a materials ability to withstand any method of wearing down or rubbing away by means of friction. This point should be taken into consideration if you are planning to use a rubber or plastic mold for construction applications. Some of these application would include architectural precast concrete, cast veneer and flexible form liners. In construction applications you want your material to provide enough flexibility, while being durable and insuring a long useful life.

Have an upcoming project? Have questions or need assistance selecting the right material for your job? Give us a call at 800-307-9218. Our team of technical experts and sales representatives are happy to help!




Say Hi To Us In Louisville

We’re happy to be exhibiting for the first time at The Precast Show being held at the Kentucky International Convention Center located in Louisville.

The Precast Show is is the largest precast-specific trade show in North America and the one place where you can find the industry’s most important suppliers and foremost equipment experts under one roof.

This years show will run between February 28th through March 2nd and will provide a great opportunity to see new products, network with industry professionals and have a little fun too!

If you’re at the show stop by Booth #1251 to learn about our mold and casting materials, caulks and sealants, deck coatings and much more!

Five Benefits of Precast Concrete Products


A recent study predicts that the global precast concrete market is expected to reach $130.11 Billion by 2025.

Precast concrete is a construction product that uses a reusable mold during the manufacturing process to form concrete into its desired shape. This method has many benefits over traditional methods.

It Saves Money

Traditionally concrete has been cast using steel or wood molds that take a long time to build, increasing labor costs. Most of the time these molds are used once and then discarded. Precast molds are commonly made from rubber and can be used hundreds of times before being replaced.


With multiple types of rubber, shore hardness and pot life options precast concrete products can be used in multiple applications. These applications include but are not limited to architectural concrete, cast veneer, stone, flexible form liners, sound walls, retaining walls and many more!


Precast concrete pieces that are poured off-site are able to be manufactured in controlled environments, limiting the effects of bad weather and producing a more consistent product.


Precast concrete products are more than just functional, they can be decorative too. These products can be molded into different configurations and shapes that can enhance your building project. Some design elements that can be incorporated into precast concrete products are stone patterns, masonry patterns, arches, cornices and many more!


Products made using precast methods arrive on the job site ready to be installed. This eliminates the need to order raw materials, eliminates the time to set up forms and lowers labor cost.

Volatile Free, Inc. ® has noticed an increased demand for precast concrete products from its customer base and has created the 3100 Series line of rubbers to service those needs.

If your company is involved in precast concrete make sure to stop by booth S12453 at the World of Concrete. Not attending World of Concrete? No problem you can still request more information and samples of our 3100 Series by calling 800-307-9218.



Holiday Schedule

Just a friendly reminder VFI will observe the following holiday schedule:

December 24th: Office Closed For Christmas Eve

December 25th: Office Closed For Christmas Day

December 31st: Office Closed For New Year’s Eve

January 1st: Office Closed For New Year’s Eve


New Product Alert: Urethane Plastics 4100 Series


Volatile Free, Inc. ® recently launched the 4100 Series line of urethane plastics.

The 4100 Series line of products are unique, low viscosity, 1-to-1 mix ratio urethane plastics designed for easy processing and demolding.

These 70 D shore hardness products offer a high hardness plastic with excellent strength and impact resistant properties.

“With two different pot life options, the 4100 Series can be used in multiple applications and gives customers the workability their unique projects need,” says VFI ® President, Nancy Hochmuth.

Applications include:

  • Casted Industrial Parts
  • Poured in Place Support for Equipment
  • Theming Components & Structures
  • High Strength Protective Coatings
  • Prototype Models
  • Taxidermy
  • Decorative Jewelry
  • Signage
  • Miniatures
  • And Much More

For more information on the 4100 Series product line visit our website at, give us a call at 800-307-9218.


New Product Alert: Urethane Rubbers 3100 Series


Volatile Free, Inc. ® is proud to announce the launch of the 3100 Series line of urethane rubbers.

The 3100 Series line of products are high-quality, two-part, easy-to-use liquid urethane mold rubbers that have excellent wear resistance.

“These products are easy to use, and can be poured, brushed or sprayed to prepared surfaces,” says VFI® President, Nancy Hochmuth.

The 3100 Series line of products offers users multiple advantages including:

  • High Tensile & Tear Strengths
  • Excellent Casting Detail
  • Easy-to-Use
  • Made from 100% Solids
  • Two Different Pot Life Options
  • Lasting Product Performance
  • Multiple Sizes Available

For more information on the 3100 Series product line visit our website at, give us a call at 800-307-9218 or stop by our booth at the World of Concrete, Booth #S12453.



Be Our Guest


Volatile Free, Inc. ® is heading to Nashville, Tennessee for the International Roofing Expo held from February 11-13th at Music City Center. The International Roofing Expo is the premier trade event for the roofing construction and maintenance industry.

The Expo Hall has reached its maximum capacity and that means multiple opportunities to network, attend educational seminars, gain new product knowledge and have a little fun too.

Whether you’re an old friend or don’t know us yet we’d love to see you. Register now for a Free Expo or 10% Off Conference Super Pass. Make sure to stop by Booth #611, we’re looking forward to seeing you at the show!

Case Study: Farha Roofing uses SEALGUARD SILICONE system to restore an EPDM roof!

Roof History

Farha Roofing got the call to come out and inspect an 80,000 square foot shopping center type facility. The owner explained that the Single-ply, EPDM, roof was out of warranty and starting to leak. Farha Roofing found that in addition to leakage there was also some ponding water, making SEALGUARD VFI-990 SILICONE an excellent choice.

Before: EPDM roof with ponding water

The Solution

Farha Roofing chose to use a Volatile Free, Inc. Roofing solution. This included:

1.  VFI-#11 Water Based Epoxy Primer

2.  VFI-Butyl Tape


Primed roof with VFI-#11 Water Based Epoxy Primer

The Installation

First, Farha Roofing thoroughly cleaned the EPDM roof. Second, they applied the VFI-#11 Water Based Epoxy Primer for the best adhesion. Third, Farha used Butyl Tape to seal seams, termination and penetrations that needed extra reinforcement. Last, they spray applied SEALGUARD VFI-990 SILICONE to complete the project.

Butyl tape installed on necessary seams to prevent leaks

The Result

This system stopped all leaks, restored integrity to the roof and saved the business a costly tear off.

After: SEALGUARD VFI-990 SILICONE coats the entire roof!

Product Information

VFI-#11 Water Epoxy Primer is a general purpose, two component, water based, epoxy primer. It provides excellent adhesion and superior strength to most metal, mod bit/BUR, single-ply, concrete and wood.

The SEALGUARD VFI-990 SILICONE is a cool roof coating and is UL, Energy Star, Miami Dade, FM and T24 certified. SEALGUARD VFI-990 SILICONE is also  a single component, high solid roof coating. it forms an elastomeric waterproof, white membrane and protects your roof from water damage and UV deterioration.