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Concrete Casting News from the Hill and Griffith Company

VOC-Compliant Form Release Agents

Posted by Hill and Griffith Company on May 7, 2020 8:08:16 PM

Excerpt from the October 1992 article from Concrete Construction by Marilyn Palmer

New types of form release agents comply with latest environmental and safety regulations

Environmental concerns and worker health and safety issues influence many aspects of the construction industry. The use of form release agents is no exception. Where once a contractor could use a few gallons of diesel fuel from the local filling station, regulations may now require the use of a volatile organic compound (VOC)-compliant form release agent.

Traditionally, form release agents have been grouped into these categories: petroleum oils, emulsions, nonreactive coatings with volatile solvents, waxes, and chemically active agents. Many newer form release agents, however, do not fit neatly into one of these categories. For example, an emulsion and a chemically reactive ingredient may be combined in one product to gain the advantages of both. Though products in these categories are still available, environmental regulations are steering the form release agent industry toward producing products with fewer VOCs.

Proper application of a water-based, chemically active form release agent can yield a smooth, relatively unblemished concrete surface.

 Proper application of a water-based, chemically active form release agent can yield a smooth, relatively unblemished concrete surface
 

Lower VOC levels and hazard ratings

Many of the new types of water-based form release agents are the industry’s answer to the latest environmental and safety regulations for VOC levels, toxicity, carcinogens, flammability, and hazard ratings. A few oil-based agents on the market also comply with the new regulations.

Lower VOC levels are a key feature of the latest water-based agents. The products produce fewer aerosols and help to minimize odors, air contamination, and damage to the ozone layer. Workers breathe fewer vapors and generally have fewer skin irritations. Water-based products are nonflammable and have low hazardous material ratings for transportation, storage, and personal protection. Several are biodegradable, allowing product and container disposal in non-hazardous landfills.

Other advantages of water-based agents

Most water-based release agents contain a chemically reactive ingredient that forms a barrier film between the form and the concrete to inhibit adhesion. Manufacturers claim the chemical reaction at the form concrete interface minimizes bugholes and staining of the concrete, producing a smooth, relatively blemish-free finish that requires little touch-up. Many water-based products are nonresidual and will not adversely affect subsequent use of curing agents, sealers, and coatings applied to the formed concrete.

Form type compatibility claims for water-based agents show few limitations. Manufacturers indicate some agents should not be used with expanded polystyrene or natural rubber forms. To ensure adequate compatibility, apply the agent to a test panel under actual job conditions.

Read More


More News from Concrete Construction

Selecting and Using Form Release Agents

Choosing and Using a Form Release Agent


Hill and Griffith Customer Service

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Bulletins and Technical Papers for Concrete Casting Products

 

Tags: Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Pipe, Concrete Form Release, Concrete Construction Magazine

Concrete Form Release Agents

Posted by Hill and Griffith Company on Mar 26, 2020 11:10:32 AM

When you’ve chosen the form, you’ve narrowed the choice of release agent

Excerpt from the article in Concrete Construction by Sidney Freedman

A form release agent must do several jobs:
• permit clean release of formwork from the hardened concrete during stripping
• protect the form work for long life and extensive reuse
• help produce a hard, non-powdery, stain-free concrete surface with a minimum number of defects
• prevent corrosion of steel forms and consequent staining of the concrete surface
 
Form release agents fall into a number of categories, each of which has a distinctive influence on the concrete surface. These are described in detail in the next article in this series. The principles by which they are chosen and the kinds used in various applications will be described later in this article, but first, their handling and application will be discussed.

Site storage

Release agents should have a reasonably long and stable storage life and should not be susceptible to damage from extreme temperature changes or from rough or repeated handling. Care should be taken to ensure that release agents are stored in accordance with the manufacturer’s recommendations, particularly with regard to temperature extremes. Before use, the release agents should be checked for sediment. To ensure uniformity, it may be necessary to stir them adequately. Care must also be taken to ensure that they do not become contaminated. Release agents containing volatile solvents must be stored in airtight containers to prevent a change in concentration. Release agents should not be diluted at the job site unless specifically permitted by the manufacturer. Some oils have a critical emulsifier content and dilution makes the emulsion unstable and causes poor performance.
 
Concrete Form Release Agents Help Form Removal

Application

The manufacturer’s recommendations on the rate of spread and the method of application should be sought and followed. The optimum rate of spread will depend on both the type of release agent and the surface condition of the formwork.
 
Form surfaces should be thoroughly cleaned, preferably before erection; forms that are continually reused are generally treated with the form release agent just after stripping and cleaning. Also, whenever possible, the application of the release agent should be so timed that it can dry or be absorbed into the formwork before the reinforcement is installed. This procedure prevents loose rust or dirt from the reinforcement from subsequently showing up as marks on the concrete surface. The release agent should be applied carefully to avoid contacting reinforcement or adjacent construction joints. A few release agents may have their chemical characteristics changed to some extent if directly exposed to strong sunlight for a few hours, and their application may have to be timed accordingly.
 

Application methods

Any of various application methods can be used, depending on the type of agent. Spray or rolling methods are most commonly used because they are inexpensive and they produce uniform films. When spraying, a low-pressure, fine fog fanning out from the nozzle is most desirable.
 
Agents can also be applied by brushing, mopping, wiping or dipping, but the first three methods do not produce a sufficiently uniform film. Great care should be taken to see that the wide brushes or soft brooms used for applying the release agent are clean. It is best not to use cleaning solvent on any tools used for applying release agents, but if a solvent is used, care must be taken to ensure that it is completely removed before the tools are reused.
 
Usually, the dip method of applying release agents is not practical for use on the job site. Therefore, when dipped coatings are required for lumber or plywood, pre-dipping at the mill is the most practical solution. Where a heavy application of an inexpensive coating is allowed, such as where the appearance of the concrete surface is not critical, the roller, mop or broom methods are all applicable. The wiping method is typically used only when very light film applications are required on hard surface form materials or when excess release agents previously applied by other methods must be removed.

Read More


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Recylced Concrete Combined With Wood Creates New Material


Hill and Griffith Customer Service

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Bulletins and Technical Papers for Concrete Casting Products

 

Tags: Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Pipe, Concrete Form Release, Concrete Construction Magazine

Producers' Guide: Form Release Agents

Posted by M.K. Hurd on Mar 5, 2020 8:00:00 AM

Excerpt from the February 2000 Concrete Construction Article by M.K. Hurd

Concrete form-release agents represent only a small fraction of the cost of a manufactured concrete item, but they have a big influence on the quality and success of the concrete surface.

Though no American Concrete Institute or ASTM standards define these products, common usage suggests that form release agents are materials containing proprietary reactive ingredients specifically formulated for use on concrete forms. ACI 301-96, “Standard Specification for Structural Concrete,” does, however, give performance-based requirements for release agents. Section 2.2.1.30 says to use “commercially manufactured form-release agents that will prevent formwork absorption of moisture, prevent bond with concrete, and not stain concrete surfaces.”

Concrete Form Release Application photo

Today, precasters can choose from among hundreds of form-release products, and new ones are still being developed. Many changes have been introduced as manufacturers scramble to meet federal and state environmental regulations, particularly with respect to volatile organic compounds (VOCs).

With the myriad form-release products available, how do you select the best one for a particular application? Here are a few of the fundamental questions you should ask:

  • On what form surfaces can it be used?
  • Will it provide clean, easy release without damage to either the concrete or the form?
  • Will it produce a stain- and blemish-free concrete surface?
  • Is it compatible with admixtures in the fresh concrete and with surface coatings that may be applied later to the hardened concrete?
  • Is it ready for use without site mixing, and is it appropriate for anticipated casting and curing temperatures?
  • Is it user-friendly and compliant with environmental regulations?

The table on pages 61-68 answers some of these questions and summarizes manufacturers’ recommendations for many currently available form release products. How release agents work Release agents are classified by how they work rather than what they contain. Two basic categories are barrier agents and chemically active agents (also referred to as reactive agents). Some release agents are a combination of the two types. Barrier-type release agents create a barrier between the form surface and the fresh concrete, preventing the concrete from sticking to the form

Read More

Hill and Griffith Customer Service

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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete, Casting Solutions, Concrete Casting Products, Concrete Casting Supplies, Concrete Casting, Precast Concrete, Concrete Form Release Agent, Concrete Construction Magazine

Formwork Rust: Reasons and Prevention

Posted by Hill and Griffith Company on Jan 23, 2020 8:00:00 AM

Excerpt from the April 2007 issue of Concrete Construction by Peter Boos and Reiner Haerdtl

Rust on steel formwork leads to stains on the concrete unit

Introduction

Steel formwork is used in prefabrication operations because of its robustness and reusability, as well as its ability to produce prefabricated units with smooth surfaces. On these steel molds, brownish-reddish rust spots sometimes form while the concrete hardens. This rust could lead to brown or red spotty discolorations on the concrete surface lower the concrete element's appearance. Removing these discolorations by sanding and resurfacing is costly and time-consuming.

Rusted Concrete Form

Reasons for corrosion

There are several reasons for metal corrosion, and thus different forms: contact corrosion, crack corrosion, inter-crystalline corrosion, pitting corrosion, etc. The corrosion of iron and/or steel is an electrochemical process in the presence of water and oxygen. Metal corrosion occurs at the spot with the higher electro-negative potential. Here, the metal ions dissolve from the surface into the solution and when they collide with hydroxide ions they precipitate as iron hydroxide.

The resulting iron minerals are formed, depending on temperature and air humidity. Due to constant recrystallization, no permanent protective rust layer is formed on the surface that would prevent further corrosion. Corrosion is prevented by protective coatings, such as greasy lubricants, a coat of varnish or other metals that prevent air and moisture from contacting the iron surface. Unfortunately, under the daily production load of a prefabrication plant, no protective layer will last long.

The appearance of rust on steel formworks can look quite different. While some steel molds rust over their whole surface, others show rust spots arranged linearly like pearls on a string. In other cases, rust spots occur only along the edges of the casting tables near the clamps. Frequently, rust appears periodically in certain seasons and disappears. Most causes for rust formation can be classified as process-related causes or environmental causes and causes related to concrete technology.

Process-related causes

Steel in direct contact with concrete forms a protective passivation layer in the alkaline milieu of concrete, which suppresses rusting. This hardened non-carbonated concrete is the best corrosion protection for reinforcement. Release agents are used to ensure reliable separation of the concrete from the formwork. This means that it acts like a contact barrier between steel formwork and concrete. Due to that, the formation of the protecting passivation is either slowed down or totally suppressed. Nevertheless, release agents prevent the direct contact of water to the steel surface. But a reliably effective form release agent is no rust protection agent for steel formwork, although a release agent may well contain small amounts of rust inhibitors. By taking the thinness of the release agent layers into account, no rust protection can be provided in this way.

In concrete's alkaline state, the metallic oxidation of the steel required for this effect to materialize does not take place. Rust can therefore develop only where water films or specific chemical elements and compounds enable oxidation, for example, in case of condensation water. It is always recommended to consult the supplier of the release agent when problems with rusting arise.

Magnets can promote rusting of steel casting tables, especially in contact with water. Clamps are placed over the magnets and positioned on the steel tables. When the magnets are placed on the casting tables before the surface has been sprayed and protected with release agent or when the steel surface underneath the clamps are not fully covered by the release agent, rust is more likely to occur. Typically, linear rust spot patterns are due to magnets.

Removing rust mechanically, such as by sanding, can lead to "activated" steel surfaces, which are especially prone to rust. Some manufacturers of casting tables sand the steel surfaces as a service. After sanding, the surface is treated with waxes and chemicals that penetrate deeply into the pores of the steel, which protect it from rusting for a period of time. Without such a treatment the formwork will definitely show rusting.

But this provides no long-term solution unless the real reason of the rust problem is eliminated. In the long-term, new rust will develop and the protective layer will wear off in the course of ordinary mechanical load. When the cause of rusting is analyzed and eliminated the rust spots will generally encapsulate themselves on their own (deeply embedded black rust).

Using chemicals to remove rust or attempts to form a protective coating on the casting tables, such as by phosphorizing, are usually no solution. The black coating that is produced in the process is not resistant to the mechanical load imposed on the surface during production and chips off, so steel surfaces can rust again. This chemical treatment may even lead to additional black discolorations on the concrete surfaces.

Environmental Causes

Read more

Technological Causes

Read more

Recommendations for Prevention

Read more


Hill and Griffith Customer Service

We're known for our hands-on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water and non-petroleum concrete form release, biodegradable releases, rust inhibitors and concrete dissolver products that suit your needs.

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Tags: Concrete, Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Casting Products, Concrete Release Agents, Concrete Construction Magazine

Applying Concrete Form Release Agent

Posted by Hill and Griffith Company on Jan 16, 2020 8:00:00 AM

Excerpt from the August 2010 issue of Concrete Construction

Q: How often should concrete release agent be applied to plywood form panels?

A: Plywood forming panels usually are treated with a concrete form release agent at the mill, but it's still important to evaluate their condition carefully before using them for the first time. Unless the mill treatment is reasonably fresh, the panels may need another treatment of release agent before the first use. Even medium-density overlays should be treated with a chemical release agent before the first use and between each pour. 

Concrete_From_Release_1

Applying a thin film of concrete form release agent to both reused panels and new panels that are not freshly mill-treated will:

  • prolong the panel's life
  • enhance its release characteristics
  • minimize the potential for staining the concrete

Apply the release agent a few days before using the forms for best results.

You also should determine whether an edge sealer was applied at the mill, and if not, seal any cut edges with two coats of polyurethane paint or varnish before the first pour. Otherwise, the forming panels will absorb moisture and swell at the edges.

Read more


Hill and Griffith Customer Service

We're known for our hands-on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water and non-petroleum concrete form release, biodegradable releases, rust inhibitors and concrete dissolver products that suit your needs.

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Tags: Concrete, Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Casting Products, Concrete Release Agents, Concrete Construction Magazine

Coating Tilt Up Concrete Walls

Posted by Hill and Griffith Company on Oct 24, 2019 3:55:17 PM

Originally published in the March 2011 issue of Concrete Construction

Q: The painted surfaces of some of the tilt-up concrete walls on our projects seem to develop blisters, peeling, or flaking shortly after application. Sometimes this occurs after it rains. Is there anything different about tilt-up walls that makes this happen?

A: As with any paint or coating project, the key to good results is paying attention to the three Ps: Prep, Prime, and Paint. Procedures for painting and coating concrete surfaces are different from other surfaces, and tilt-up concrete surfaces do require special preparation.

Causes of Defects on Tilt Up Concrete Walls

Surface Preparation: The most likely reason for blistering and peeling in a tilt-up wall, especially if it occurs shortly after it rains, is failure to remove the mold release agents and bond breakers used for casting the concrete component.

This is the big difference between tilt-up concrete and other forms: It is cast on the jobsite in concrete forms. After the concrete wall or column has cured, a mobile crane tilts the piece up and moves it into place, where it is braced into position and secured. Painting contractors may not always be fully aware of this because they arrive on the jobsite after the walls are in place.

To prevent the concrete from adhering to the molds, contractors apply release agents, or bond breakers, to the mold before the concrete is poured. These release agents can be solvent-based, water-based, oil-based, silicone-based, silicone-free, silicone water-based and many other proprietary combinations. But they all perform the same function—they create lower surface energy between the concrete form and the concrete to mitigate adhesion. The objective is to be able to lift the cured concrete from the casting mold smoothly and cleanly.

Unfortunately, release agent residue also can inhibit adhesion of coatings and paint to the concrete surface. Most painting contractors are aware of this, and paint companies do a good job of educating painters about the need to remove release agent residue before painting or coating tilt-up concrete surfaces. Power washing at the specified pressure using the specified cleaning solvent should do the trick, but there are two cautions.

One, be methodical and thorough when power washing. Two, there is a trend toward making release agents and paints/coatings more compatible, but it is always prudent to power wash the surface first. Even with “compatible” release agents, if too much was applied to one area, it could swamp the system and adversely affect coating adhesion.

All concrete surfaces must be washed before coating to remove dirt, dust, and excess sand anyway, so always take the extra step of power washing tilt-up concrete to remove any release agent residue, whether they are compatible or not.

Read More


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Concrete Form Maintenance


Hill and Griffith Customer Service

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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Form Release Agents, Concrete Casting Products, Concrete Casting Supplies, Concrete Pipe, Concrete Safety, Precast Concrete, Grifcote FR 50 Concrete Form Release, Bio Gold Concrete Form Release, Grifcote, Concrete Construction Magazine

ACI Releases New Building Code Requirements for Structural Concrete

Posted by Hill and Griffith Company on Sep 12, 2019 4:58:19 PM

ACI 318-19 was published in response to new engineering practices and industry changes.

Article excerpt by Jack Moehle published in the Concrete Contractor August/September 2019 issue.

The American Concrete Institute (ACI) published ACI 318-19: “Building Code Requirements for Structural Concrete in July 2019, in response to new engineering practices and industry changes.

ACI 318 presents requirements for design and construction of structural concrete that are necessary to ensure public health and safety. The document is intended for engineers and building officials, but because it addresses materials advancements and applications, it is expected to have an impact on jobsite procedures. It is anticipated the final code requirements of 318-19 will be referenced in the 2021 International Building Code (IBC).

318_19_cover_highres2.5d39ca6a430aa

New Engineering Practices Translate to Changes in the Field

  • ACI was prompted to make updates in the code due to:
    • new technology (computers used for design and analysis by engineers and architects)
    • increased construction of tall buildings
    • the need for seismic resistance
  • New requirements include:
    • minimum reinforcement on interior column-to-slab connections
    • longer bar lengths for thicker, two-way slabs
    • additional transverse reinforcement
  • Updates include
    • expansion of permissible applications of high-strength reinforcement
    • new requirements for material properties of high-strength steels
    • several changes to strut-and-tie method (STM) for design of discontinuity regions
    • clarity on Anchorage-zone reinforcement

New Materials Addressed

  • IBC shotcrete provisions were included
  • Post-installed concrete screw anchors are now recognized

Alternate Cements and Aggregates

  • Now includes provisions for alternate cements and aggregates
  • No details are readily available for these materials because not enough industry testing is available

Read More


More Concrete Contractor News


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Casting Supplies, Concrete Safety, Precast Concrete, Grifcote FR 50 Concrete Form Release, Concrete Form Release for Wood, Bio Gold Concrete Form Release, Gricote, Concrete Form Release Agent, Concrete Construction Magazine

Selecting and Using Concrete Release Agents - Excerpt

Posted by Hill and Griffith Company on Sep 6, 2019 5:35:38 PM

Enhance the quality and economy of precast products by using the right release agent

Article excerpt by John A. Koski published in the Concrete Construction March 1994 issue.

Almost every precaster has had a double-tee or an architectural precast panel crack as it was being removed from a form. In some cases, an ineffective or improperly applied release agent may have been the culprit. At other times, the wrong type of release agent may have been used. Knowing how to properly use form release agents and which agent should be used for a particular application can go a long way toward preventing costly mistakes. In addition, following proper procedures and using the right agent can enhance the quality and economy of a finished precast piece.

Less is better with Precast Concrete From Release 3

BASICS OF USE

  • Make sure the release agent you are using is compatible with the form or mold it is being used on. For example, some release agents can cause an adverse chemical reaction when used on foam or rubber forms.
  • Don’t purchase a release agent based on price alone. When examining prices of comparable release agents, compare them based on their cost per square foot of coverage, not by the cost of a 5-gallon pail or 55-gallon drum.
  • Protect form release agents from temperature extremes. Release agents that have frozen and then become liquid again may have had their form release properties altered or destroyed. Extremely high temperatures also can damage the properties of release agents. 
  • Thoroughly mix or agitate release agents that require mixing or agitating. This ensures proper dispersion and continuity of the chemical components within the release agent. Always follow manufacturer recommendations when considering mixing or agitating. Some release agents don’t need to be, or shouldn’t be, mixed or agitated.
  • Make sure workers wear respirators, goggles, face shields, gloves, and other protective clothing as required by the manufacturer and government agencies. Make sure workers are properly trained in all aspects of the application process. This includes not only safety concerns, but also how to properly apply the release agent being used. The application technique workers use, however, may not be appropriate for the new product and can cause it to perform unsatisfactorily or not at all.
  • Before applying the release agent, remove any buildups of concrete, rust, scale, or dirt that may be on the forms.
  • Repair any holes, fractures, or other defects in the forms. Just prior to applying a release agent, make sure that the surfaces of the forms are clean and free of water, dust, dirt, or residues that could be transferred to the surface of the concrete or affect the ability of the release agent to function properly.
  • Make sure that forms are coated uniformly with no gaps, sags, runs, or beads. To avoid these problems, never apply a too-heavy coat. Sags, drips, and runs should be removed as recommended by the manufacturer.
  • Make sure spray equipment is working properly. 
  • Do not over-apply a release agent, especially when using a release agent that is chemically reactive.
  • On new wooden forms, thoroughly saturate the forms according to manufacturer directions before placing concrete.
  • It is best not to wait an excessive amount of time after applying the release agent and before placing concrete as dust and other airborne contaminants can form a light coating over the release agent
  • If the concrete is to be painted, plastered, or have other coatings applied, be sure to use a release agent that won’t prevent the coating from bonding with the concrete.
  • Don’t allow release agents to contact reinforcing steel. Doing so can prevent the concrete from bonding to the reinforcement.

Read More


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Don't Miss the Tilt-Up Convention & Expo


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Casting Supplies, Concrete Safety, Precast Concrete, Grifcote FR 50 Concrete Form Release, Concrete Form Release for Wood, Bio Gold Concrete Form Release, Gricote, Concrete Form Release Agent, Concrete Construction Magazine

Choosing and Using a Form Release Agent

Posted by Hill and Griffith Company on Aug 15, 2019 3:16:52 PM

Excerpt from the article by M.K. Hurd in the October 1996 issue of Concrete Construction

Concrete Form Release Agents Help Form Removal

Most form materials require the application of a release agent to prevent adhesion of concrete to the face of the form. Many form oils and other release agents adequately prevent sticking, but using the correct type of agent for the form material can also help to minimize concrete color variations, staining, bugholes, and poor surface durability. Article discusses the two basic types of release agents (barrier and chemically active), how to select a release agent for different form materials, and release-agent application methods. It also describes the newer types of water-based release agents, which are formulated to meet environmental regulations limiting volatile organic compounds (VOCs).

Photo caption: Forms will strip cleanly and easily if you use the correct form release agent and apply it properly. - Photo by Bob Sawyer

With the wide range of release agents available today, how do you choose the best one for your forms?

Types of Release Agents Historically, form release agents have been grouped in the following categories :
• Petroleum oils
• Emulsions—either water- or oil-based
• Nonreactive coatings with volatile solvents
• Chemically active agents
• Waxes

Though products in these categories are still available, new products and new formulations are being introduced to meet environmental regulations limiting volatile organic compounds (VOCs). Also, manufacturers may combine release-agent types, such as a chemically reactive product and an emulsion, to produce a product that has the advantages of both. Many newer form release agents, therefore, do not fit neatly into the above categories. Because environmental restrictions have caused changes in the commercially available agents, and because of the great variety of chemical formulations, manufacturers now simply classify release agents in terms of how they act instead of what’s in them. The two basic categories are barrier agents and chemically active agents. Read More.

Precautions in Selecting A Release Agent

A release agent may be incompatible with concrete that contains a number of admixtures. Compatibility problems have been reported when chemically active agents were used with concretes containing microsilica, high-range water reducers, and unusually high amounts of admixtures. Be sure to discuss possible compatibility problems with the admixture and release-agent suppliers. Read More.

Application Methods

Use enough release agent to prevent adhesion, but don’t apply too much. When overapplied, the material runs to low points in the form face where it can retard cement hydration or produce staining. Most manufacturers recommend a thin, uniform coating. With some products, the thinner the better; sometimes as little as 1 ⁄2 mil (0.0005 inch) is recommended on nonabsorbent form surfaces. Read More.

Precautions to Take During Release Agent Application

•Keep release agents off construction joints and reinforcing steel. To avoid spilling release agent on rebar, apply it before placing the steel.

• Never use release agents containing wax or silicone if the concrete surface is to be painted.

• Follow manufacturer recommendations for when to apply release agent. Some agents must dry or cure before concrete is deposited, while others can be applied only minutes ahead of concrete placement. Generally, the shorter the time between applying release agent and placing concrete, the better. Too long a wait can result in the agent drying out, running down the form face, or being washed away by the rain. (Note: Some agents are rainproof.)

• If there is any ponding or puddling of release agent, be sure to wipe away the excess material.

• After coating form faces, protect them from contamination and weather.

SELECTING A RELEASE AGENT FOR DIFFERENT FORM MATERIALS

Read the complete article in Concrete Construction Magazine


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Three Key Lessons About Moisture in Concrete


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Tags: Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release, Concrete Construction Magazine

Article Review - Selecting and Using Form Release Agents

Posted by Hill and Griffith Company on Mar 22, 2019 5:54:36 PM

Here are a few highlights of a great article by John A. Koski that was published in Concrete Construction Magazine

Enhance the quality and economy of precast products by using the right release agent

Almost every precaster has had a double tee or an architectural precast panel crack as it was being removed from a form. In some cases, an ineffective or improperly applied release agent may have been the culprit. At other times, the wrong type of release agent may have been used.

Highest quality precast concrete plant -2

Knowing how to properly use form release agents and which agent should be used for a particular application can go a long way toward preventing costly mistakes. In addition, following proper procedures and using the right agent can enhance the quality and economy of a finished precast piece.

When examining prices of comparable release agents, compare them based on their cost per square foot of coverage, not by the cost of a 5-gallon pail or 55-gallon drum. For example, two release agents may sell for the same price for a 55-gallon drum. However, one may have an estimated coverage rate of 800 square feet per gallon while the other can cover an estimated 1,100 square feet per gallon. If they are equal in performance and other attributes, than the one with the greater coverage rate is a better value.

Make sure that spray equipment is working properly. For example, a partially clogged spray nozzle can deliver a release agent in spits and spurts, allowing a too-heavy application in some areas and none in other places. Also, make sure that the spray tip is the right size for the product being applied. A tip that provides spray that is too fine or too heavy can create problems.

Biodegradable Concrete Form Release Agents 2 copy

Do not over-apply a release agent, especially when using a release agent that is chemically reactive. These release agents chemically react with the alkali in concrete to form a thin release film. Applying too much of the release agent can cause excessive surface dusting on the finished concrete.

Although these suggestions may help solve some of the problems pre-casters experience, if you continue to have problems with a release agent, call the manufacturer. Reputable manufacturers maintain technical-assistance departments designed to help solve problems and improve product quality. If a manufacturer can’t or won’t provide you with the answers or information you need in a timely fashion, consider switching to one who will.

Read the entire article here.


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Hill and Griffith Customer Service

We're known for our hands-on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water and non-petroleum concrete form release, biodegradable releases, rust inhibitors and concrete dissolver products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »

 

Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
Contact Us »

 

Bulletins and Technical Papers for Concrete Casting Products 

Tags: Concrete Form Release Agents, Concrete Release Agents, Concrete Forms, Concrete Casting Supplies, Concrete Form Release, John Koski, Concrete Construction Magazine

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