1. Q. What’s the mix ratio (water to HoldTight® 102) for a 48-120 hour flash-free window and elimination of most or all soluble salts? (Use potable water: Very hard water or water high in chlorides is not recommended: consult HoldTight Solutions Technical staff if water quality is a problem.)
A. For wet or water abrasive blasting (water injection, slurry, “water ring”)
Blast cycle. Start with 250:1. If flash occurs, decrease water portion (increase HoldTight® 102portion) in 50:1 or 100:1 increments until there is no flash (e.g., 150:1; 100:1; 50:1) NOTE: If blast water is not under pressure or is not accelerated through a venturi nozzle, start with 100:1. This is typically the case with an external water ring apparatus. For small jobs in which changing ratios is impractical or for jobs in which soluble salt contamination and moisture in the air is known to be quite high, start with 100:1 or 50:1.
Wash down (rinse) cycle. Begin as soon as practical after the blast. Start with 50:1 with wash down water of at least 500 p.s.i. and water flow rate of at least 2 g.p.m. If wash down water is 2000+ p.s.i. at 2+ g.p.m, start with 100:1. Then increase water portion (or decrease HoldTight® 102) until flash appears or appears before you wish it to (i.e., until your blast window is unsatisfactory).
For UHP water jetting (water with little or no abrasive at 25,000+ p.s.i.)
Blast cycle. (optional) (applicable if, and only if, pump manufacturer approves.) Start with 250:1. If flash occurs, decrease water portion (increase HoldTight® 102 portion) until there is no flash
Wash down (rinse) cycle. Begin as soon as practical after the blast. If HoldTight® 102 was used in blast cycle, start with 200:1. If HoldTight® 102 was not used in blast cycle, start with 100:1. (In either case, wash down water pressure should be at least 500 p.s.i. with a water flow rate of at least 2 g.p.m..).
If the surface is highly contaminated with chlorides and/or the water is very hard and/or the surface is deeply pitted or profiled and/or weather conditions are marginal, it may be necessary to decrease water and increase HoldTight® 102 from the recommended start ratios to 100:1 or 50:1, respectively.
For dry blasting (wash down only, of course)
Start with 50:1. Wash down pressure should be no less than 500 p.s.i. at 2+ g.p.m. 1,500+ p.s.i. is highly recommended. Then increase water portion (or decrease HoldTight® 102) until flash appears or appears before you wish it to (i.e., until your blast window is unsatisfactory.)
How to SAVE TIME AND MONEY, remove soluble salts and contaminants, incidentally, prevent flash rusting
Here’s why the answer is “Inhibit… but only with HoldTight® 102“:
You can blast all day or even for 2 or 3 days — often 4 or 5 — before you have to stop, reorganize your setup, and paint. Fewer interruptions in the flow of the work; fewer setups; less switching around and re-scheduling of crews and equipment saves hard dollars.
You can avoid multiple secondary abrasive or high pressure water blasts to remove the rust bloom or soluble salts, saving time, cleanup and disposal costs. Sweep blasts to remove flash rust also generate dust, one of the problems water is used to solve.
You can use less when you need less by adjusting the mix of HoldTight® 102 to water from as little as one part HoldTight® 102 to 250 parts water, to one part to 50 in some especially tough cases. How much you need is based on how much water your equipment uses, weather conditions, and the amount of contamination on the surface you are stripping. We recommend you use one to 50 on the final, quick wash down which is standard operating procedure for all water-abrasive and water blasting. Our documents, “Getting the most out of HoldTight® 102” and our “FAQ 1 (Frequently Asked Questions 1) : mix ratios” will help you decide how much you need. Our staff is available to help you come up with the most cost effective procedure for your applications.
HoldTight® 102 is low-cost protection against premature coating failure. It rapidly lifts moisture off the surface and removes contaminants, including soluble salts and blast residue, much more effectively than water alone, even water under very high pressure. The clean surface that results helps produce a quality application.
HoldTight® 102 can even improve the performance of surface tolerant coatings. These coatings are a great advance — but are primarily intended to be used when you are unable to achieve at least a commercial blast (SSPC VIS-1-89) or when you must use hand tools (SSPC VIS 3). If, for whatever reason, they are used on surfaces prepared to commercial blast or better, even surface tolerant coatings should not be applied over thick, uneven, and inconsistent flash rust (e.g., a mix of soft red rust and light brown rust). (See the two SSPC standards just noted.) HoldTight® 102 can eliminate this problem — always consult with your coating supplier, of course.
No other product, whether sold as a rust inhibitor or salt remover, has undergone such extensive testing (hundreds of coatings, thousands of coupons, by dozens of coating manufacturers) and held up so well in so many years of field service (more than 10 years without a coating failure). That’s in part because HoldTight® 102 leaves virtually no residue. And coating-damaging conductivity is not an issue with HoldTight® 102 as it is with some products.