DO NOT to use Gilsonite Oil Base Sealer...
There are many Sealcoating companies and "fly-by-nighters" promoting oil based sealers. Most times, Gilsonite contractors won’t tell you what product they’re using - so ask. They have very little equipment overhead as they don’t need big tanks that agitate the product and they use a LOT less product per square foot. They don’t clean or edge the asphalt properly and they could care less about cracks, but their profit margins are very high. Just say NO! The industry standard is coal tar emulsion, don't be fooled into using an inferior product that can potentially damage your asphalt.
Many reputable asphalt contractors must compete with "The Sealcoating Gypsies", the fly-by-night companies who come through a town offering quick work at low prices. These companies often use low-quality material as well as untrained labor. They know how to take advantage of owners of single-family homes.
Don't let them take advantage of you!
Some ways to protect yourself or your Business from these types of contractors:
- Be sure to get printed information on the types of professional-grade sealer to be used on the job. Preferably, this information should come directly from the manufacturer.
- Check the company's references, including names, phone numbers and addresses of past clients and number of years in business. This way you can physically inspect their work.
- Contact your better business bureau for a record of complaints filed against the company.
- Obtain a current certificate of insurance evidencing both liability and workers compensation insurance.
- Inquire about the company's industry education. Ask if they attend any asphalt/sealcoating industry conferences or trade shows.
And last but certainly not least, John Ruskin (1819 - 1900) once said of low bidders: "It's unwise to pay too much, but it's worse to pay too little. When you pay too much, you lose a little money, that is all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do.
The common law of business balance prohibits paying a little and getting a lot - it can't be done. If you deal with the lowest bidder it is well to add something for the risk you run. And if you do that, you will have enough to pay for something better."
There are basically two kinds of Sealers:
Shiny and Dull.
Sealers that dry shiny are asphalt-based, such as Gilsonite -- a cutback asphalt with a solvent. Gilsonite salesman will tell you that oil base sealant is the best because it penetrates deep into the asphalt to rejuvenate and refurbish it by adding asphalt back into the oxidized surface. What they don’t tell you is that Gilsonite Sealer is much too hard and asphalt can become brittle and crack. The sealer’s softening point is 200-210 F. The softening point of asphalt used for paving is 120-130 F. The Gilsonite Salesmen also won’t tell you the solvent dissolves and breaks down the asphalt binder. The Gilsonite wears away within a year and leaves behind damaged and weak binder. The original binder would be stronger if you had not sealed it in the first place.
Environmental concerns have been raised and Gilsonite is no longer an option.
Oil based sealers are bad for the environment, don't meet Federal Specs, and are outlawed in several states due to high VOC's. (pollutants)
Here's what pavementpro the industry association for asphalt maintenance has to say: Gilsonite, or North American Asphaltum is a natural, resinous hydrocarbon found in the Uintah Basin in northeastern Utah. Gilsonite in mass is a shiny, black substance similar in appearance to the mineral obsidian. It is brittle and can be easily crushed into a dark brown powder. Some companies manufacture pavement sealers with Gilsonite as a base material. A drawback to these sealers is the necessity of solvents, usually mineral spirits (paint thinner) to dissolve the Gilsonite. Improperly or over applied these solvents can damage asphalt pavements.
Here's what the University of Nevada has to say about Coal Tar:
Based upon it's historical performance and widespread usage compared to other available products, refined Coal Tar Emulsion remains the most effective and continues to be the preferred pavement sealer throughout the U.S. and Canada. Refined Coal Tar Emulsion gives the unsurpassed wear characteristics and protects the pavement from motor oil, gasoline and other petroleum products.
Pavement Coating Technology Center, Dept of Civil Engineering,
University of Nevada, Reno:
Here's a condensed version of this article from the state of NY about oil based sealers.