MOST Rust Converters Are A JOKE! Let Me Show You. (Eastwood, KBS, Corroseal, Ospho & More)

Most Rust Converters Are A JOKE! Today we are testing rust converters. We are testing Rust Kutter, Rust Eater, Ospho, VHT, Eastwood, KBS, Corroseal, Loctite, Rustoleum. Each product will be testing on light surface rust as well as heavier rust to see how well each product functions as a rust converter.

We will be testing each rust converter for bond strength, chip resistance, and flexibility. The results that I got from this testing were rather disappointing. The bond strength of most of these "primers" was terrible. The best results came from the products that had high concentrations of phosphoric acid.

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00:00 Intro
1:04 How my testing was preformed
2:24 Types of tests I will be running
3:55 Aerosol Rust Converters
7:12 Brush on Rust Converters
9:16 Phosphoric Acid Rust Converters
11:32 Heavy Rust testing
13:58 Final Thoughts

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[RepairGeek]

Products used in this video:
Help support the channel, buy using my Amazon links
As an Amazon Associate I earn from qualifying purchases and your cost is exactly the same.

[paulbriggs]

Problem with all this- either you are testing a true rust converter which makes iron oxide into black iron phosphate, OR you are testing a coating MIXED with a rust converter so that when it dries it's (ideally) a rust-free coating. The chip test has no bearing in testing a true rust converter, same with the bending test. Your own words were that it was "To test how flexible each COATING was." Well either you are testing coatings or you are testing true rust converters which are not coatings at all but just what they say they are, rust converters. Most of the inferior "rust converters" are in fact an acrylic type coatings mixed with a mild phosphoric acid blend. They do convert rust but are just an acrylic coating in the end which can never be any better than acrylic paint in protection. Even if you put epoxy over them, its only as good as the acrylic paint underneath and nobody recommends acrylic paint to protect steel. As you said, if the primer fails, the paint on top fails. ANY product that turns rust black is likely phosphoric acid even if its just mild, but good for you for checking the MDS info to see if there actually was any in there. However, as I said, anything that can be peeled off is not a true converter. Thanks for putting me onto Rust Kutter. I learned more from your video than I expected.

[chrisgraham]

The only product I've used in Canada is a rust converter made by Rust Check. It's a phosphoric acid formula with the consistency of water that can be brushed or sprayed. It does convert iron oxide (rust) to ferric phosphate. Once converted the actual ferric phosphate does not rust...it's chemically impossible. Re-rusting occurs when the product fails to convert all the rust and rust is left behind. Re-rusting also occurs when barriers are breached allowing moisture and oxygen to reach the virgin metal under the ferric phosphate, so it's the virgin metal rusting this time. When a rust converter is applied to rust, the converter must remain wet for a period of time to allow the formula to soak into the rust all the way to the bare virgin metal. Applying a rust converter just as a film on top of rust has little or no value. Start by removing as much visible rust as humanly possible or reasonable by grinding, wire wheels, sanding or your preferred method. Apply the first coat of rust converter as an indicator tool. When it converts and turns the remaining rust black and it's now more visible, now it's time to sand, grind and remove as much of the black converted ferric phosphate as possible. For auto body panel repair, use a Dremel tool with a precision grinding bit to attack as many remaining black specs that you can, like the dentist does a root canal with his drills. Now you should have shinny metal with very minor black specks remaining. Now apply 2 coats of rust converter, again keeping it wet to penetrate into the pits of the metal. Allow the final coat of rust converter to dry for a minimum of 24 hours before applying a quality rust inhibiting alkyd paint with 2 coats. It's tedious work and you may need to be OCD to endure it. I have autobody and frame repairs/conversions that are in excess of 12 years old, with no signs of failure. Auto rust IS automotive cancer and must be treated the same way. Surgically cut out everything possible and treat what you may have missed with chemotherapy (rust converter).

[speedmaverick]

I've been using Naval Jelly since the 70's and have had outstanding results with zero failure. The longest I have tracked it has been just over 20 years with no return of rust from under paint. It's messy as it has to be rinsed and smells terrible so needs to be used in ventilated area, but the results have been excellent. Just used it last week for an RV project that had rust inside the sleeper floor structure that I was able to remove and treat.

[Testostebro]

Thank you for this. My father and I have my late grandfather's older car, with not a lot of mileage on the tires, but a lot of years under its belt. A leak developed in the trunk weather stripping, water caused some rust to form under the spare tire. Your video has taken me to Rust Kutter, and it's doing for me what your testing showed you. Subscribed as a thanks and a very heartfelt thank you.

[LiveWire-itzr]

Rust encapsulaters and rust converters are very different but the terms in marketing are used interchangeably. Encapsulaters cover the rust and keep it from getting worse by sealing it over; usually epoxy based. Converters are almost always acid based and must be top coated once converted and neutralized.

[mjremy]

A much needed video. Nothing like upending established market products. Good job!

For a long time I used Loctite Rust Neutralizer thinking what a godsend it was. It bonded existing rust and I could then paint over it. No! This product is a combination of tannic acid and acrylic. The tannic acid is the rust remover and chemically converts the rust into a neutral state, but the acrylic is a useless base coating that should never be under any other type of paint. Tannic acid chemically converts the reddish iron oxides into bluish-black ferric tannate, a more stable material but it can also corrode metal and is not the best rust remover/ converter/ neutralizer. The reason some of your tested products did not work, is due to tannic acid being used.
Some beginner DIYers (as I was once) don't want to spend the time understanding chemistry. They want a quick one step does it all solution. For them, let them continue using Tannic Acid products as it is safer than the stronger stuff like phosphoric acid, muriatic acid, etc.

Phosphoric Acid etches the rust off the metal better than Tannic Acid. This is what is in the Rust Kutter you recommended. It can be dangerous to apply, fumes in lungs and eyes, back splash, spatter, all dangers that need protection with goggles, neoprene or thick nitrile gloves, working in open spaces, skin protection, etc.

Why not use straight phosphoric acid?
1 part 99% phosphoric acid added to 4 parts water is a 25% solution.
1 part 85% Phosphoric acid added slowly to 4 parts water is close enough to a 20% solution.
You typically need a 20 - 30% diluted PA for rust removal.
Remember to add PA (acid) to water, not water to acid in decrease danger of splashback and spatter.
On Amazon, here is 1 quart 85% PA at $13, search for:
Duda Energy 1 Quart / 950ml 85% Food Grade Phosphoric Acid Rust Remover Clean Etch Metal

Is phosphoric acid harmful to humans?
Phosphoric Acid can affect you when breathed in. Phosphoric Acid is a CORROSIVE CHEMICAL and contact can irritate and burn the eyes. Breathing Phosphoric Acid can irritate the nose, throat and lungs causing coughing and wheezing. Use protection!

Why do they put phosphoric acid (PA) in Coke?
Acids provide a tartness and tangy taste that helps to balance the sweetness of sugar present in the beverage; they are key factors in the taste of the beverage. Phosphoric acid is added to cola drinks to impart tartness, reduce growth of bacteria and fungi, and improve shelf-life. When you drink sodas, the PA damages your bones and gives you osteoporosis. Apart from the harmful effects of the sugar, salt, caffeine, and dyes in sodas. Do not drink sodas.

What happens to teeth in phosphoric acid?
Soda also contains phosphoric acid, which is highly corrosive to the teeth. To get an idea of just how erosive it is: phosphoric acid is also used in fertilizer and metal polish. Even small amounts can erode your teeth's enamel.

fyi - Don't say 'literally' and 'actually' in your speech. They are overused and a bad habit. Everyone has a few 😊

[marko.]

One advantage of the Ospho is since it is very thin it will wick in between sheetmetal pinch welds and crimped panels

[draytonkk]

I've had good experiences with rustoleum rust converter, went on clear, turned rust black, and as long as all thick rust was removed as is wire brush it thoroughly but not needed to be to bare metal, just down to surface rust only, it lasted and worked great, my project car on hold sat in my driveway for 4 years now and isint rusting where I used it, and I spent maybe 30 hours over 2 weeks wirebrushing the WHOLE underbody and wheelwells and using that as a primer layer, then a black primer onto after, then rubbercoated it all, and no rust coming back with Canadian winters too so from +35c to -45c temp ranges, salt from my asshat brother burying it when shoveling the sidewalk while I was living on my own for a bit, its held through

[JasonAirInc]

Good video. Im building a 29 Ford Tudor that spent decades in the woods and has ZERO paint left. This is a huge help. Thanks for putting this together.

[James-ndyk]

With the phosphoric acid, you are also meant to rinse them with water after your done etching or soaking the items, to neutralize/remove any remaining acid.

[doebs]

I was directed to your page on rust conversion and top coating/ sealing the floor of my classic. Your very in depth. Your testing is much appreciated.

[oldmanhare]

I used VHT Rust Converter on my Tacoma frame which had visible surface rust along every weld on the frame. After all the visible rust turned black, I went over it with a flat black Rustoleum. 3 years later, and they all look perfect. No separation or blistering at all. Now, on other bare metal surfaces like the suspension parts that had no coating from the manufacturer, I did have to repeat this process roughly every year.

[kovie]

Through personal experience I've found that despite what rust converter products claim, you can't just convert existing rust into iron phosphate or the like and them paint over it and be done. Unless it's very light surface or flash rust, you still have to get rid of the existing rust first, or as much of it as is possible, and only then apply a converter, preferably with a high phosphoric acid and possibly zinc content, and then you still have to apply paint or primer and paint over that.

There is no all-in-one rust remover, converter and encapsulator product for most real world rust situations. I've stopped believing the marketing hype and now use these products for what they do best, converting whatever remaining rust exists AFTER I've gotten rid of as much rust as I can via other means, be they chemical, mechanical or electrical. They're kind of a middle step in the rust removal and treatment process, and used this way can be quite effective.

Rust converters aren't snake oil. They're just marketed as such.

[will]

I began using OSPHO when starting out as a deckhand on offshore tugs. It was an industrial/marine product only back then and was hard to find someone who would sell it retail. I used it then, and still do as a way to stabilize rusted steel (not thin sheet stuff) after chipping, grinding rusty and scaly steel that had been subjected to wear and saltwater-where you can't or would not blast it. It was excellent then and still is for those HD uses. I use it as a pre-primer before epoxy or other top quality primer..

[jstmesegscell]

Yes. We actually use ospho in some of our aircraft parts. You do need to remove access rust, apply it, and leave it to cure for 24 hours and then remove the access scale or powdery substance on top. Then after that you can prep amd paint over top. An acid brush is good to use to apply it. But it being thin helps it seep into the pores and through the metal. You just have to make sure you wait for it to cure and then the removal of the surface "film" it creates is important. Usually use and solvent to remove that.

[ercost]

Great video! Just wanted to add that I used Dupont (then) Extend on some car rust-thru spots ~40 years ago with fabulous results. Zero rust since then, and the car has never been garaged, always out in the weather.

[robbieraychannel]

Thank's for the great video. Fortunately I already use the Rust Kutter brand. I'd like to share a tip with everyone. I work on tons of snow and salt equipment and whenever I try to do a wiring repair job the copper strands are black with corrosion no matter how far you strip the insulation back. Like everyone I generally sand or scrape it off as best as I can. One day I thought I'd try the Rust Kutter. It works great. Turns it back to shiny copper again. I pour some into a bottle cap and swish the bare wire end around in it for a few minuets. when done I rinse it off with water then spray with CRC battery cleaner to neutralize the acid and rinse again. Sounds time consuming but makes a great repair. Might also work on other non ferrous metals, maybe you could do some testing. ???

[vadrifter]

Much appreciate the fact that you do go the xtra mile in your testing. Marketing almost always seems to win until real world applications are put into motion.
Have you done a video on rust encapsulators? Eastwood comes to mind first. Also there are some AG paints that have so pretty high self praise.

[Rocheman]

FYI for people in Canada. Rust check rust converter sold at Canadian tire is available in a 236ml bottle not the spray can one. And if you get the bottle one it’s a acid based product like the ones he recommends in the videos