About Seal-Line Techniques, LLC We are a family owned and operated business. If you call us you will speak directly with the owner. We take pride and guarantee our work. We use only Seal Master products and apply at the recommended rates. Some other companies will “water it down” which is why some sealcoat jobs only last 6 months to a year. We pride our selves on honesty, and having our customers clear on what to expect for their money.