KNOCKOUT Rust Converter & Primer

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KNOCKOUT Rust Converter & Primer

$38.95 Taxes

(7 customer reviews)


Packaging: Sold online in 1 quart container.  Larger sizes (1 gallon, 5 gallon, and 55 gallon) available.  Please call 888-776-2242 for more information.

Coverage: Approx. 80-100 square feet per quart. 360-400 square feet per gallon.

Knockout safely converts rust back to black steel and leaves a primed, paintable surface.

Simply knock off any loose rust scale, wipe clean, and apply with a brush or roller.  Knockout will be dry in minutes, forming a clear acrylic surface that can be painted or coated.

Knockout is recommended for use on wood deck fasteners prior to the application of Encore’s deck coating or other paint.

Knockout’s unique formulation stays where you put it.  Where other rust converters are water-thin and run, Knockout stays in place, even on vertical and overhead surfaces!



A Water-Based Primer That Converts Rust.





KnockOut lies beneath the painted surface, providing the protection you need.


KnockOut is setting a new standard in safe, water-based priming systems – even for the most demanding applications.

KnockOut can be applied with an airless sprayer, brushed, or rolled.  Knockout is unlike other converter/primers because it’s thick enough to stay in place on vertical surfaces without sagging.  It can be sprayed overhead and won’t drip.

KnockOut converts within seconds, dries within minutes, and can be top-coated with any paint or coating that is compatible with an acrylic film.  Only one coat is required, which saves considerable time and material expense.

KnockOut has surpassed other types of converter/primer systems in ASTM and Petroleum Institute testing by as much as 10:1 in service life testing (salt fog chamber and salt-water submersion).  See test report.

KnockOut is available in 55-gallon drums, 5-gallon drums, 1 gallon and 1 quart containers.

Applications include: Marine. bridges, ships, barges, offshore platforms, oil and gas pipelines, marina dry stack storage, steel sheet piling, aluminum sheet piling, etc.  Inland.  amusement parks, steel staircases, water towers, golf cart bridges, and countless other home and farm applications.

KnockOut is compatible with Encore products.

Knockout is perfect for treating nail heads on outdoor decking prior to applying Encore, Cool, RustOx, or other paint/coating product.  Simply brush Knockout onto the fasteners or rusted steel and allow it to dry.

* Steel alloys will not blacken, but will patina instead.

applying knockout

Paint on.

rust away!

In minutes, KnockOut has converted the rust and leaves a primed finish.

Additional information

Weight 4 lbs
Dimensions 5 × 3 × 6 in

Quart, 1-Gallon, 5-Gallon, 55-Gallon

7 reviews for KNOCKOUT Rust Converter & Primer

  1. Delbert V.

    Did a perfect job on some upright steel columns. Painted right on and the product didn’t sag or migrate. It dried more uniform and faster than other converters that I’ve used in the past. I did have to put two coats of paint over it because it’s really black when it dries, but it’s doing its job, right?

  2. Tom P.

    Wonderful product. Easy to use. We coated a rusted tin roof with this product and then painted it. It’s been about six months and it’s doing a great job. We’re using it on a barn roof next!

  3. Jeremy Allman

    This is the best rust converter that I’ve ever used. The product stays where you put it and goes on very evenly when sprayed. It does leave some brush strokes if you brush it, but I guess that’s because of its consistency.

  4. Capt. John

    Five stars isn’t enough for this product (and Rustox). It has saved me thousands over my past method of rust repair, which was blasting to white, priming, and waiting 24 hours between paint coats. We used this product about three months ago on a small working barge as a trial. We gave it a light blast to get the loose stuff off, then applied KO with an airless (graco). Went on great. Dried super quick and we were able to get a coat of Rustox on about 20 minutes later. We sprayed that as well – super easy. Rustox dried in about 25 minutes and we applied the finish coat. Couldn’t be happier. No rust bleeding through 90 days later and this stuff is tough. We’ve dropped lots of stuff on the deck of the barge that would have cracked other coatings. We plan to use it on more of our equipment.

  5. Rick Bernthal

    Definitely a great improvement over other options. The salt air kills a paint job in two years here on the coast because rust begins to appear and wrecks the job – even when we prime coat the nail heads. We found this product and decided to use it. Works great on house siding nails. We spray every nail on the home prior to painting. It dries quick and we are able to paint right away. I have been painting for about 28 years and can tell that this product delivers a real solution. As an experiment, we applied it to a rusted beam and then sprayed it with a latex paint. Typically, we’d see bleed-through within 48 hours. It’s been about six months and absolutely nothing is coming through.

    I sell KnockOut as an upsell and have no problem doing it once the customer sees what this product can do.

  6. J. Willoughby

    I love this product. Sprays nicely and quickly converts the rust. Other converter/primers take 24 hours to convert and dry where this one took about 10 minutes. It was fascinating to watch the rust turn to black. Product dries fast and leaves a good tack finish for overcoating. I used the other encore product to top coat, but figure that just about anything would stick well to it.

  7. Bill Bixx

    Works great. Better than any other product I’ve used. Just sprayed the bottom of my barge and you could see the conversion taking place as the product was being applied. Compared to my last bottom job, this product cut my time by 2/3rds. Just make sure you get a good solid coat the first go around because any holidays will let rust through. That may be the reason why other primers require more than just one coat. Very satisfied with this product.

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