Holdtight 102 is not a coating. It performs its two principal functions–salt removal and flash rust prevention–as an adjunct to and enhancement of pressure washing with water (and/or wet abrasive blasting, “wet jet” blasting, or “water jetting”). Thus, the question of “How much 102 must I apply to a given area?” is irrelevant. The more relevant and meaningful questions, instead, would be: How much water will I use when I blast and/or pressure wash a specific area, given the equipment I am using and the time it takes to wash? How much surface area do I cover in a given amount of time? The answer to those questions will determine how much Holdtight 102 will be required.
The amount of water needed is based on flow rate, production rate, and the surface area. This total is then divided by the dilution ratio you have chosen: 50, 100, and so on. Different flow and production rates will apply, of course, when water is used as part of the stripping process in wet-abrasive blasting. In such cases, Holdtight 102 must be used both in the stripping or removal operation as well as in the wash down operation.
After dry- or wet-abrasive blasting, we know from experience that 102-treated water applied at flow rates of less than 1 gallon per minute under less than 500 psi at the surface is not sufficient to remove dust and paint particles. This is even the case after the surface has been “blown” clean with air only. In fact, “blowing” a surface clean of dust generated by the abrasive blasting operation may result in adding even more contaminants from the compressor onto the surface. When such contaminants remain on the surface, flash rusting will occur.
We also know from experience that the cleanest surfaces are achieved with 102-treated water over 500 psi at 2-3 gallons per minute. In most cases 2 gallons per minute at 1,500 psi or higher will achieve the best results. At these recommended flow rates and pressures, operator productivity is simply not a critical factor. The water flow and pressure rather than the “dwell time” are the determining factors so long as the water is treated with Holdtight 102. If the operator, in those cases, moves the wash wand or tip very quickly over the entire targeted surface, he will use less Holdtight 102 without jeopardizing surface cleanliness. If he moves slowly, he will use more Holdtight 102, but will achieve the same result.
Based customer experience, these operations typically “clean” 500 to 1,000 square feet per hour. (Production rate is of course a function of operator skill and strength, surface flatness vs. surface irregularities, and constraints imposed by positioning equipment, scaffolding, lifts, etc.) If the water does not contain Holdtight 102 in the recommended ratio, the surfaces will flash rust. If the water is significantly substandard–in terms of chlorides or other contaminants and/or carbonates–as discussed in our literature on the subject, the surfaces might “flash” or “turn” even with Holdtight 102. In such cases, either increasing the Holdtight 102 to water ratio or pre-treating the water, or some combination of both, will be necessary.