When people talk about asphalt paint they can mean two completely different products. There is paint that is applied to asphalt and then there is paint which contains asphalt to be used as a waterproofing for such things as metal objects which are exposed to water and the environment. We will look at both of these options in this article.
Painting Asphalt
If you are contemplating painting your asphalt driveway or parking area then you will want a product that is designed to coat and seal the existing blacktop. Many people are under the mistaken assumption that liquid asphalt is the best product for this considering the original material was an asphalt and aggregate concrete mixture which was applied to the roadway. The problem with this thinking is people do not understand why the asphalt works well in the concrete mixture. In order to make the aggregate (small rocks, gravel, or stones) stick together, the bonding material needs to be heated to between 400 and 600 degrees before laying it out. Then a heavy construction roller is utilized to press the mixture together. This creates a mechanical bond that is very tough and long lasting.
If you try to paint an asphalt without the heat it will not set up correctly and will just make a big mess. The best product to paint your driveway with is actually a coal tar product. Coal tar is a by-product of steel production and is very sticky. It also contains a high percentage of VOCs (volatile organic compounds), as these VOCs gas off they will leave a coating on the surface that wears very well and offers a great moisture sealer.
There is a concern with coal tar though, the compounds that gas off are flammable and unhealthy. Therefore, this should not be used in a garage or basement. Only apply this sort of sealer in an outside environment.
Asphalt Impregnated Paint
The second type of material that is considered asphalt paint actually is composed of liquid asphalt. This paint is a very good moisture barrier for metal items that will be submerged or subject to water. It used to be very common as a wood preservative but that is no longer the case any more as more effective and safe products have come on the market. Generally, you do not see asphalt paint used much for coating metal or other items any more either because new, high tech coatings are being discovered and produced every day which do a much better job. Also, there is a safety issue. Asphalt does not lend itself to non slip additives like an epoxy or latex product will.