Below are general guidelines for applying sealer based on a typical application scenario.
Number of coats: Two, Normally
First coat – 40 square feet per gallon
Second coat – 60 square feet per gallon
Dry to touch: 30 minutes to I hour.
Between coats: The first coat must not only dry, but also cure sufficiently to prevent pickup before the second coat is applied. Shady or sheltered areas may require a longer drying time. Allow at least 2 hours between coats on residen- tial driveways so as to minimize pickup or tracking. All manufacturers recommend 24 hours between coats or before opening to traffic.
Methods of application: Apply sealer with a brush in the trimming areas. For the most efficient sealing job possible use a spray sealing applicator capable of mixing and blending, with an agitator, sealer, and sand.
Directions for application: Mix until the sealer is of uniform consistency. Mechanical mixing is recommended and will lessen time in obtaining uniform consistency. Do not apply when temperature is expected to drop below 50 degrees F., or if rain threatens before the sealer is cured. Application is recommended early in the day or when at least 2 hours of sunlight remain upon completion of the job.
Thick coats will not cure readily and could result in pickup and tracking. After the first coat is cured, apply second coat so that all pores are sealed. To determine whether the first coat is cured sufficiently, use the thumb test. At various locations and while exerting approximately 10 pounds of pressure, twist thumbprint 90 degrees. Lack of pickup on thumb indicates sufficient curing of the first coat, and indicates you should be able to continue with your second coat.
To provide traction on smooth surfaces or grades, we have found that normally 5 pounds of clean dry silica sand with each gallon of sealer will provide you with a uniform mix. The gradations of the sand should meet the following:
Sieve Size 30 — 100% Passing
Sieve Size 60 — 0-15% Passing
The sealer and sand must be mixed in machine while applying sealer to insure an even distribution of sand over the sealed area, Best results are obtained when the sand slurry coat is applied in both coats equally. The sand slurry coats can be applied more efficiently and evenly by a spray application designed and developed by Neal Mfg. Co., Inc.
TYPICAL APPLICATION OF SEALER: SUMMARY
This is an outline of the steps on the application process and not specific instructions for each procedure. We will deal with that elsewhere. Also note that all crack filling should be done a week prior to sealing when using cold pours. Most manufacturers recommend a minimum of 60 days curing time.
1. Check weather forecast for the day
2. Block off the work area
3. Begin general cleaning of the pavement
- Clean and prime oil spots
- Remove growth and deposits from edge of pavement
- Check oil level and start air broom
- Scratch out and blow out cracks
- Dry up wet spots
- Brush and blow off dirt puddles
- Take air broom to windward side of pavement and start systematically blowing all dirt away
- Start agitator and run for five minutes
- Start pump and start trimming
6. Begin to sealcoat the pavement
7. Inspect area for spots missed
8. Check placement of barricades, police area for tools, complete information on job work order
9. Next day remove barricades
10. Stripe as soon as possible using water base paint
FACTORS WHICH AFFECT HOW THE JOB IS COMPLETED
- Size, shape, and grade of the pavement; work so the material will be flowing down hill if there is an appreciable grade
- Coarseness of the pavement
- Prior sealed surface
- Man power
- Serviceability of equipment
- When the job can be done, and length of time it is open to work on
- The amount of repairs to be completed
- Accessibility to water and sand
APPLICATION TIPS AND TECHNIQUES
- Keep relative humidity in mind when determining the amount of water that should be added to the mix. RULE: If humidity is high, add less water.
- Longer passes with the applicator will make a better finished appearance.
- Keep sealer off adjacent concrete surfaces; mask them off if necessary.
- Between coats, put away unnecessary tools and always keep applicators clean.
- Complete work orders promptly and keep account of material application rate.
- Workers should know their job and be able to speak intelligently about what is being done. They should always be neat appearing and alert to perform their task.
- Keep truck on cleaned pavement once you start application. Consider sealing an area where you will end the first coat to set the truck on while you wait to start the second coat.
- Never run the truck over partially dried material.
- Don’t block your equipment in on job completion.
- Fill truck with gas and material at end of day.
CLEAN UP PROCEDURES
Following good clean up procedures is important from two standpoints: To promote optimum efficiency of tools and equipment and to project a good public image in the eyes of the customers, there are some procedures which will make this as easy as possible for your crew.
The first rule to follow is, whenever possible, wash all tools and equipment used on application with water immediately following their use. If you can rinse these tools before the sealer dries they will wash up cleanly and easily. Ideally a container (a 22 gallon drum is ideal) with water, you can wash the tools and filter, is recommended.