Frequently Asked Questions
What people ask when the rust is already there and a decision has to be made.
Can It Be Stopped?
Can rust really be stopped, or only slowed down?
Genuinely stopped. The reaction requires iron, oxygen, and liquid water in contact simultaneously. Take away the water and the oxygen with a continuous barrier of adequate thickness and the electrochemical cell has no current path. It does not proceed slowly — it does not proceed. The condition is that the barrier must be continuous and stay bonded.
Do I have to remove all the rust first?
You have to remove everything loose. Sound, tightly-adhered oxide can stay and be sealed under the membrane — once it is dry and starved of oxygen it is inert. The dividing line is whether a putty knife can lift it. Leaving loose material means the coating will release with it later, so this is not a corner worth cutting.
Do rust converters work?
Converters chemically transform surface oxide into a more stable compound, and on light surface rust with a proper topcoat over them they have a legitimate role. Their limits are real too: they need the right amount of rust to react with, they do not penetrate scale, and they are not a barrier by themselves. On a heavily corroded asset a converter is not a substitute for mechanical removal of loose material plus a thick continuous membrane.
How do I know if the steel is too far gone to coat?
Ultrasonic thickness readings compared against design, or a tap test if you have no gauge — a dull thud, a dent, or perforation means section loss. Coating restores nothing structurally; it only prevents further loss. If the member is already below required section it needs a welder or replacement, and we will tell you that rather than sell you material.
Doing It Properly
What about deep pitting — can it be sealed?
Polyurea bridges and fills shallow pitting easily at 20 to 60 mils. Deep pits are a different problem: the chemistry inside a pit is oxygen-depleted, chloride-concentrated, and low pH, and sealing that in place traps an active cell. Deep pitting needs to be cleaned out and the area tested for chlorides before coating.
The asset has been on salted roads. Does that change anything?
Substantially. Chlorides must be washed off and verified below 7 µg/cm² before coating. Salt sealed against steel drives osmotic blistering — water is pulled through the film toward the salt, the coating lifts, and the corrosion continues underneath where you cannot see it. Wash, dry, test, and retest if it fails.
Can it be coated over the old paint that is still on there?
Usually, with 7001 primer, provided the old paint is sound. Test it: if the existing coating tears within itself when pulled, it all has to come off. Where it is well bonded, 7001 promotes adhesion and blocks bleed-through from the aged finish.
Should I fix the leak first, or coat first?
Fix the water source first, every time. A coating over an active leak or a drip path is a delaying tactic. Find out why that area is wet — an open lap, a failed gutter, a condensation path, a wash-down pattern — and address it, then seal the metal.
Time, Cost & Getting It Done
How long is the asset out of service?
The coating is tack-free in 10 to 30 seconds and back in service typically within the hour. Prep and masking drive the schedule, not cure time. Most single-asset jobs fit inside one shift, and there is no second coat to come back for.
Can I do this myself?
You can do the prep yourself — wire wheeling, degreasing, washing. The barrier layer cannot be brushed or rolled; it gels within seconds of the components meeting and requires a plural-component proportioner with heated hose. Most people hire an applicator, and we can refer one in your region.
What does it cost compared to just repainting it?
More up front. The relevant comparison is what happens next: repainting a rusting asset usually means repainting it again in a few years, because a thin film over a rough oxidized surface has thin spots at every high point. Sealing it once and having the reaction actually stop is generally cheaper per year, and much cheaper than the replacement it defers.
What warranty applies when you coat over existing rust?
SP3 power-tool prep over sound tight rust carries a reduced-warranty note, and we state that plainly rather than in fine print. Full warranty terms require SP6 blast with verified profile, chloride limits, and documented DFT. Many owners take the reduced-warranty route knowingly, because the alternative is doing nothing.
Situation Not Covered Here?
Most corroding assets are a bit unusual. Describe yours and we will give you a straight read on it.
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