Q: How many coats of sealer should I use?

A: For light to moderate traffic we recommend 2 coats. For high-traffic areas we recommend two coats with a third coat applied in the drive lanes.

Q: How much modifier should I add per gallon?

A: We generally recommend 1-3% added per gallon of concentrate. Traffic conditions, choice of modifier, and weather conditions dictate the amount added.

Q: Why should I use modifiers?

A: Modifiers allow the user to match the appropriate mix design to the specific project and weather conditions. Higher traffic areas require different mix designs than lower traffic areas and residential applications. Modifiers will also allow the user to vary their mix designs to match the weather conditions.

Q: How much sand should I add?

A: We generally recommend 1-3 pounds of sand added per gallon of concentrate.

Q: What role do sealer additives play in viscosity?

A: There is a wide range of sealer additives available, some designed specifically for either asphalt or refined tar based sealer concentrates, and each with different benefits for the cured seal coat membrane.

Many of these additives function to increase sealer viscosity. Sealer and sealer additive manufacturers provide recommendations for use of their products, and include mix design tables which may depict higher ranges of water dilution with increased additive dosage. This is often to compensate for the additive’s anticipated thickening effect by prescribing increased dilution water to readjust viscosity of the mix back to an optimum range for application.

The effect a given additive may have on viscosity properties of different sealers, however, is not universal, even among the same type of sealer from different manufacturers. Regardless of the additive type, dosage used, or prescribed mix design, extremes in viscosity of the applied mix should be avoided. The potential benefits of any additive cannot overcome defects from poor mechanical bond or non-uniform thickness of the cured film caused by excessively thick or thin consistency of the applied material. The contractor should rely on his or her own experience and consult both the sealer manufacturer and additive manufacturer for guidance with untried additive/sealer combinations and mix designs to avoid problems.

Q: What mix design should I use?

A: Mix designs vary with the type of modifier used, volume of sand added, weather conditions and pavement traffic. GemSeal sells a variety of latex additives to enhance performance of our sealers. Our Ultra modifier builds viscosity and requires additional water for dilution. Our AQS and Rapid-Set increase the viscosity minimally.

For our Ultra Modifier, in general we recommend adding 2-3% per gallon of concentrate sealer, 2-4 pounds of sand per gallon and 35-45% water (45% for hotter southern conditions). Batch example: for every 100 gallons of concentrate, use 2-3 gallons of Ultra, 200-400 pounds of sand and 35-45 gallons of water.

For AQS and Rapid-Set, in general we recommend 2-3% per gallon of concentrate sealer, 1-3 pounds of sand per gallon and 30-40% water (40% for hotter southern conditions). Batch example: for every 100 gallons of concentrate, use 1-3 gallons of AQS or Rapid-Set, 100-300 pounds of sand and 30-40 gallons of water.

Q: What is the best mix design?

A: Mix designs are best chosen for the pavement traffic, weather conditions, and modifier.

For better wear conditions we recommend the higher percentage of modifier and sand added without over-dilution of sealer. In general, for Ultra, AQS and Rapid Set, use 3-4% per gallon of concentrate, 35-45% water (45% for hotter southern conditions) and 3-4 pounds of sand per gallon.

For residential or light traffic areas we recommend the lower range, which consists of 1-2 % Ultra, AQS, or Rapid Set, 30-35% water and 1-2 pounds of sand.

Q: How much water should I add per gallon?

A: Over dilution of the pavement sealer dramatically decreases the life of the pavement coating. For optimum results, we recommend always adhering to an appropriate mix design. In general, we recommend the water dilution at 30-40%. Use the higher end of the range with substantial modifier and sand added; use the lower end of the range with minimal modifier and sand added.

Weather conditions also impact the need to vary your water dilution. In very hot conditions, a little extra water is required for proper application. In cooler spring and fall conditions water should be keep to the lower end of the range.

Q: What is the coverage rate per gallon?

A: In general, 70-90 square feet per gallon (or 0.08-0.10 gallon per square yard) of diluted pavement sealer. Coverage rates will vary dependant upon mix design and application techniques.

Q: What should the temperature be before application?

A: Many in the industry say that the temperature should be at least 50°F and rising for a 24-hour period. At GemSeal, we believe that you will get better results if temperatures are at least 60°F and rising, with a sustained high of 70°F and no rain forecasted for 24 hours. Ideal conditions for sealer application are 70°F with a pavement temperature of 70 degrees, 40-60% humidity and sunshine.

Lower ambient temperatures and high humidity substantially impact curing times. The proper mix design and addition of our modifiers greatly enhance the curing, durability, and longevity of our pavement sealers.

Q: How long should I keep traffic off after application?

A: Generally we recommend 24 hours after final application.

Q: What is the proper mix sequence of products?

A: Concentrate sealer, water, modifier, and sand.

Q: Which is better brush or squeegee application?

A: Both are recommended and highly effective. The proper mix design, coverage rate, and application also have a substantial impact to the life of the coating.

Q: What is the difference between drying and curing?

A: Drying is visually seen by the observer. A pavement coating can be dry to the touch but still need additional time to reach its appropriate cure point. If traffic is allowed upon the coating too quickly, i.e. before curing, then premature wear is possible. We always recommend 24 hours after application for final cure to occur. This will, of course, vary with weather conditions, humidity, temperature, and mix design.

Q: How will humidity affect drying of the sealer?

A: Higher humidity and cooler temperatures impact the curing process of the pavement coating. Higher humidity over 50-60% restricts water from evaporating properly from the pavement coating. Lower temperatures below 70°F also slow the curing process. Appropriate usage of modifiers will assist in drying the pavement coating.

Q: Can I sealcoat at night and get good results?

A: Some property owners hire a contractor to do “night work” so that drive lanes and parking areas are closed only during the overnight period. However, even with modifiers and a proper mix design, sealer needs sunlight to achieve proper curing. Sealcoating at night is possible, but opening traffic before curing will result in poor performance of the coating.

Q: Where is the testing done?

A: Each GemSeal plant has its own on-site quality control lab, which performs tests to continually monitor the emulsion process and the product as it is being manufactured.

Q: Is all sealer manufactured by GemSeal actually tested?

A: Yes. In addition to periodic tests during manufacture, all material produced is quarantined, re-tested, and certified – before it is released to the customer.

Q: Do you test raw materials?

A: Yes. All incoming raw materials are tested for two things: to ensure uniform properties prior to their use in production, and to ensure that raw materials meet our stringent specifications. Tests are also performed to closely monitor each stage of the production process.

Q: I hear about “solids content” being important. What is “percent solids”? How is it measured?

A: All emulsion based pavement sealers contain water. Solids content is the relative weight content of the total product which is not water. Solids content is tested by weighing a sample of sealer before and after it is heated at a specified temperature and time to remove the water and other volatiles to determine the weight fraction of the remaining residue or ‘solids.’

Q: What does solids content of a sealer concentrate mean to the contractor or property owner?

A: The simple answer is that solids content is what you are paying for. This is a generally reliable index of sealer quality. The percent solids number should represent the relative content of functional ingredients in the base sealer formulation – not including added aggregate or non-functional fillers – which can increase the measured solids content artificially.

Q: What is solids content of a sealer mix design? Why is it important?

A: Solids content of a sealer mix design is generally interpreted as the solids component of the combined sealer concentrate, dilution water, and liquid additives. Mix design solids determines how much of the applied coating will remain as a cured film after the liquid evaporates during curing. Sand content of the mix is usually left out of this calculation, because traction aggregate in a mix is not part of the binder membrane, and contributes relatively little to the cured film thickness. Higher solids content in the sealer concentrate product translates to allowing higher water dilution in the applied mix design.

Q: Can solids content be too high in a sealer mix design?

A: Yes. Besides the higher job cost and potential problems that come with applying a thicker consistency mix, use of mix designs containing less than the manufacturer’s recommended water dilution (i.e. solids content too high) are generally not advisable. In some instances under-diluted or excessively rich mixes (especially in heavier applications) can result in drying and curing problems, even under ideal weather conditions.

Q: What is ash content? Why is it tested?

A: Simply stated, ash content measures the relative proportion of clays and other mineral components to asphalt or refined tar binder resin in a pavement sealer formulation. It is performed by placing a pre-weighed sample of dried sealer residue into a small laboratory furnace. The weight of the remaining ‘ash’ after all organic resins (like asphalt and tar) have been burned off represents the percent mineral content of the sample. The ash test results are used to verify that proportions of the pavement sealer formulation are correct and meet specifications. This protects the user from buying a poor-performing sealer with too much clay and too little binder resin.

Q: What is viscosity? How is it measured?

A: The basic definition of viscosity is a fluid’s resistance to flow. There are a many methods designed to measure viscosity, and almost as many viscosity units of measure as there are methods. Even for a single test method, some materials can exhibit different viscosities under different conditions (pavement sealer is one of these). In the sealer industry, the most widely used apparatus to test product consistency is the ‘Brookfield Viscometer’, a laboratory device which measures viscosity in ‘centipoises’ units, (cP). [100 centipoises (cP) = 1 Poise (P)]. For the layman, a material with a higher viscosity feels thicker, and conversely, sealer with low viscosity feels thinner or flows more easily.

Q: Is the viscosity of sealer concentrate important?

A: As an indirect measure of other important properties, yes. We monitor viscosities incessantly during and after manufacture to detect viscosity changes, which could indicate subtle changes in raw material properties, or deviations in the emulsion process. For the contractor, viscosity of the sealer concentrate is usually a good indicator of value. Higher viscosity = higher solids = greater value. Higher viscosity in the sealer concentrate product also (but not always) translates to allowing higher water dilution in the applied mix design.

Q: What role does viscosity play in sealer quality and performance?

A: Sealer viscosity, specifically viscosity of the diluted sealer mix design, can significantly influence the quality and even performance of a seal coat project in several ways. First, maintaining suspension of sand in the job mix tank and subsequent uniform sand distribution during application is dependent on proper mix viscosity. Secondly, application viscosity of the seal coat mix can also be a key factor in performance and durability of the seal coat project. If consistency of the applied mix is too thick, inadequate wetting and flow of the film into small voids of the pavement may weaken bonding and adhesion of the coating to the surface, leading to flaking or delamination. Conversely, if viscosity is low, and consistency of the mix is too thin and runny, applied material tends to drain off higher plateaus of the surface topography and sand particles into pavement voids and crevices, leaving less cured film of sealer on the higher surfaces where it also receives the most wear and abrasion. This characteristic can cause the appearance of early coating wear and poor customer satisfaction. One of the primary requirements in formulating a successful sealer mix design is to avoid either of these viscosity extremes.

Q: What makes the GemSeal service different from your competitors?

A: Our precison manufacturing process, expanded tank storage, and large tanker delivery fleet allow us to meet the needs of our customers even during peak weekends. We also negotiate national contracts for raw materials that allow us to keep a steady supply of products for our customers. As a single company that owns nine manufacturing plants, we can ensure that our processes and service are always consistent. Service is a priority in our business and you can count on us to meet your delivery needs.

Q: GemSeal claims Saturday deliveries…what kind of lead time is needed for that service?

A: We usually request a 2-day lead time, although many times we deliver within one day.

Q: I have my own tank. Can I come by on any Saturday to fill my equipment? Do I need an appointment?

A: No appointment is needed; our plants are open on Saturday for pickups during the season.

Q: I have a small company and our normal average demand doesn’t allow for us to have an excessive amount of sealer on hand. Can we build a relationship with GemSeal that will assist us with last minute large quantity orders for jobs we don’t want to get away

A: Yes, each GemSeal facility provides drop tankers to assist contractors on large projects. Just contact your local sales rep for further information.

Q: I don’t know how to operate one of your large drop tankers. Will the drivers know what to do to offload material when they arrive at my location?

A: With regards to a drop tanker, our highly trained drivers will go over the pump-off procedures on site.

Q: What is Asphalt?

A: Asphalt is composed of mineral aggregates compacted into place and held together by petrolem-based asphalt cement, which acts as a glue or binder. A fine, cost-effective product, but not maintenance-free.

Q: How do I choose an applicator company?

A: Reputable contractors use quality materials, provide quality workmanship, and are proud of their work. Ask them for a list of their customers so that you can check references.

Q: Why does asphalt need to be sealed?

A: Sealers will protect asphalt from petroleum spills of fuel, oil, and solvents, which attack the pavement and seep deep beneath the surface, softening the asphalt and reducing adhesion. They will also protect against the sun and rain, which cause oxidation that can lead to raveling, cracks, and even potholes.

Q: Why aren't roads and highways sealed?

A: Unlike parking lots and driveways, highways are constantly re-compacted by continuous traffic. Further, highways are not subject to the continuous attack of petroleum derivatives in specific spots or patterns.

Q: What is asphalt sealer made of?

A: GemSeal sealer is made of a blend of high-grade ball clays, water, refined coal tar, and proprietary emulsifier milled into a coal tar emulsion to generate a paint-like coating which insulates the petroleum-based asphalt from potential petroleum spillage and reduces the normal aging cycle of the asphalt.

Q: Are all sealers alike?

A: No. GemSeal brand sealers have been perfected from 60 years of manufacturing and testing experience, and are specially formulated to contend with the particular paving problems of our local climates. GemSeal’s proprietary processes, industry leading quality control program, and ongoing research and development assures that GemSeal sealers – the oldest sealer brand in continuous existence in the industry – is simply the best.

Q: How long will the sealer last?

A: Depending on the current condition of your pavement, there may be a need to fill cracks, dig out soft spots damaged by petroleum spills, fill in potholes, and generally patch the pavement. Then a recommended two coats of GemSeal sealer could save you from costly repaving.

Q: Which modifier is better: Rapid Set, AQS or Ultra?

A: Each serves a different purpose and can be used in various conditions. All three increase the durability, adhesion, and deeper black color of the pavement sealer. AQS and Rapid Set increase the viscosity minimally while Ultra increases the viscosity dramatically. Increased viscosity is needed for higher sand loadings. AQS and Rapid Set will significantly decrease the drying time.

Q: How do I remove over-filled sealant from isolated areas?

A: The most common way of removal of over-filled sealant from isolated areas is to heat the existing sealant with a hawk torch. Note: When heating the existing sealant you do not have to bring the material all the way to application temperature; simply heat the sealant until it becomes soft and workable. Using the removal tool, heat the blade with your torch to as high of temperature as possible. The combination of the heat on the raised sealant and your removal tool will allow you to remove any existing sealant from the surface and in your high spots that are above the 1/8 ‘’ recess.