Oxidation, or rust, can potentially happen to any material that’s made of metal. It’s commonly seen on automobile frames, furniture, and interchangeable parts to various machines. Depending on the situation, removing it with heavy-duty tools can be either too costly or time-consuming.
Rust converter sprays are a great alternative that quickly stops oxidation before the problem gets worse. With them, you can restore metal and even paint over it once the solution dries.
Below are five of the best sold online, chosen for their ability to penetrate the rust, turning it into a sort of protective coating that’s waterproof and resistant to further oxidation. When you’ve completed the reviews, be sure to read the Buyer’s Guide to understand how converter sprays work, and which of the five is best formulated for your needs. Let’s get started!
Comparison Table of Top 5 Best Rust Converter Sprays
Use the comparison chart to know the variations in size and coverage area for the material you intend to spray it on.
Rust-Oleum Automotive 248658
Permatex 81849 Rust Treatment
Best for Single Coats
VHT SP229 Rust Convertor
Best for Light Rust
GEMPLER'S Fast Rust Converter and Primer
Best for Furniture
Rust-Oleum 215215 Stops Rust Rust Reformer
Rust-Oleum Automotive 248658 Rust Reformer Spray – Best Rust Converter for Automobile Parts (Editor’s Choice)
The Rust-Oleum Automotive Spray works great on all things made of metal, including aging car parts. With it, you can have any rusted patches fixed up almost immediately. Spraying is simple, just direct the nozzle to your intended surface until it’s covered. For thicker rust, you might need an additional can or two. You don’t want to run out of the spray whilst in the middle of your work.
It’ll begin to dry in about 40 minutes. However, give the solution another 24 hours before coating it over with a paint job.
You can apply re-coats at seen as the first coat shows signs of drying. As this is a primer, you might not have to do this at all, based on the type of rust (and the device) that you’re covering. The result appears smooth and holds well on any type of paint that you brush or spray over it. Once everything is done. You’ll love the way it prevents further rust from seeping through the parts that you sprayed.
If there is anything about the product that should be improved? Not much. Its solution is similar in viscosity to spray point and should be shaken the same. To keep the spray flowing at a consistent rate and without abrupt stops, shaking is required. Do this for several seconds before you begin, then in bursts as you work the spray over the rust. You’ll find that the spray coves out evenly in the direction your nozzle faces.
And like most rust converters, spraying in an outdoor setting is strongly advised. The odor is very strong; cover your nose with something, especially if it’s a bit windy outside. Overall, the Rust-Oleum is a perfect way to keep your vehicle parts in tip-top shape, without the hassle of getting new devices.
• Coat permanently dries in about 24 hours
• Gets flat enough to the point where a layer of paint isn’t necessary for things to appear smooth
• No chipping or flaking once the solution hardens
• The can must be shaken vigorously to keep the spray consistent
• Has a very strong odor
Permatex 81849 Rust Treatment – Best Rust Converter for Furniture (People’s Choice)
The Permatex 81849 Rust Treatment spray is an aerosol can with a large-cap on the top. Although it might not seem like much, this will prevent the strong smell that comes from the spray from lingering around the area where you store it when it’s not in use. Like the previously reviewed product, try to use it outdoors, and away from other household members.
The nizzle sprays out a large quantity in just one spritz, making it great for covering up hard to reach areas or small patches fast.
When using it in this fashion, drying time should take only a couple of minutes at most. For larger surfaces, give it about 40 minutes before spraying on an additional coating. Everything will completely harder after a day has passed, whereby you can then paint over the coats. Get another can of spray for another coat. For large pieces of furniture and the underside of automobiles, you could easily use up one can in before you even have a chance to finish everything. It’s not required for you to clean up the rust if you don’t want to, before using this product.
The black polymer may not be as dark when doing it this way, however. If the rust is thicker than the outside of the metal that it shows, prepping with a quick sanding or wire brush could help that metal look a bit smoother. But for the most part, the Permatex 81849 is an outstanding spray on its own. Recommended for people that either light or heavy-duty rust converting jobs.
• Smells don’t linger immediately outside of the bottle when the cap is placed back on the can
• Spraying in small patches typically dries within minutes
• With this product, light rust doesn’t have to be cleaned prior to spraying (although no treatment causes the result to remain brown-tinted)
• Results aren’t level enough for the can to be used as a primer alone
• Additional accessories may need to be used with this product, especially for rust that’s very thick (a wire brush or sandpaper)
VHT SP229 Rust Convertor – Best Rust Converter for Single Coats
The VHT SP229 Rust Converter makes converting rust much easier to tackle than some of the product’s rivals. This is due to the clearer finish when the solution is drying. Many rust converters will turn the liquid (and rust) into a matte black color that could make it difficult to tell what was converted, and what wasn’t. Using your eyes, this will let you know where additional re-coats are needed, and areas that you don’t require it.
As a result, you could save time and spray since there won’t be a need to touch up in places that don’t necessitate more spray.
It’s color isn’t completely clear per-se, but transparent enough to give you an idea of what’s happening to the rust that you’re treating. When the job is over, don’t worry about messing around with the spray nozzle. The liquid should come out with no problems; it doesn’t cling to the hole or cause blockages.
If the rust is thick, don’t gamble too heavily on the VHT SP229, particularly if that is the only thing that you’re using to get rid of it. Yet when sanding or grinding is done before you spray the converter, the spray will manage to work its way into all the perforations, blocking any oxidation from forming in the treated area again. Get an extra can to cover big metal sheets are large equipment unless you’re confident that you won’t need more layers to finish your restoration.
• The spray is consistent and doesn’t require too much shaking
• Comes out and stays clear, making it easier for users to see where rust has been effectively converted
• Good spray nozzle that doesn’t clog
• Difficult to get thick rust converted without pretreatment (sanding it down)
• One can might not be enough to cover large bodies of rust on automobiles (or for people who plan on making several coats)
GEMPLER’S Fast Rust Converter and Primer – Best Rust Converter for Light Rust
The Gempler’s Fast Rust Converter and Primer does exactly what its name says, which is to change and prime thick rust into a surface that’s paintable.
The black polymer solution that makes up its ingredients transforms the rust, working deep into the crevices of the iron and until there’s nothing left.
For light one-offs, just one coat should suffice. You probably won’t even need more than one for moderately thick rust either, especially when dealing with rusted furniture. Just spray it on and let it dry, seeing how well the converter penetrates to base your decision on whether or not you need more. But the best attribute isn’t related to rust at all.
Ordinary metal pieces stay and look the same after you’ve sprayed nearby rust; just wipe it off if you don’t want anything to harder over it. You’ll have to remove excess before the hardening is complete, which is a breeze to do. Although conversion might take about two hours for thick rust, except that the time for small bits to dry almost immediately. If you shave it down before you start, you’ll be able to get through the drying process for larger work quicker.
Don’t count of things going by fast otherwise. For the converter to dry out completely, give it over a day, more so if the surface area is large or has been coated several times over. If you’re the impatient type, look for another converter if your restoration involves large pieces of furniture. But if not, you’ll appreciate the Gempler’s ability to absorb rust to the point where no one could tell it was there in the first place.
• Primes just as well as it converts rust
• Doesn’t damage non-rusted portions of the metal
• Converts almost immediately
• For large coverings, the spray could take longer than a day to fully dry
Rust-Oleum 215215 Stops Rust Rust Reformer – Best Rust Converter for Furniture
The final converter, the Rust-Oleum 215215, is a spray that’s designed for priming quickly. Most of the sprays coveted will take up some of your time by having to wait for things to dry over the course of a day or two. But with this, there’s no such thing. Your metal surface should be dry in approximately one hour. For the best result, give it another hour to ensure that everything is solid before painting over the polymer.
Use it on antique wrought iron shelves, stands, or even gates. Whatever metal you throw at the Rust-Oleum 215215 will come out completely different, restored to its former glory. These benefits are mostly seen for people that live in dry climates, where you may have to wait at the same level of time as the other products if the weather is humid and/or wet. You can spray layers on fast, even when the solution’s first coat hasn’t completely dried out.
The nozzle won’t give out on you and moderate shaking during the onset of your work is all that’s needed; don’t worry about getting exhausted from having to juddering the can too often for the spray to come out. Shave off as much rust as you can before spraying with this product. It penetrates through the top layer of rust, but not thorough enough to prevent big chunks of it from getting through the converted polymer. Still, the 215215 remains a great spray for rust on most surfaces, serving as an indispensable product for home and work use.
• Primes furniture fast with little grinding/sanding needed to get acceptable results
• Drying time is quick, usually finishes in less than 24 hours
• Easy to spray on multiple layers over a short time period
• Doesn’t penetrate well through rust that’s underneath the top layer
Best Rust Converter Spray – Buyer’s Guide
The guide will help narrow down the rust converter that’s specific to your individual needs.
How to Choose the Best Rust Converter
First, check to see how thick the rust is on the metal that you intend to restore. If the oxidation has only hit a few small patches, you may only need one can to finish up your job. Larger surfaces are better treated with more than one can. Stick to one brand of spray if you can. The thicker the rust, the more that you’ll need. Three seems to be a good number for handling the toughest jobs. The average rust converter is sold in 10.25 fluid ounce aerosol cans, although some brands will allow you to purchase in a bundle of two or three.
Next, think about whether you want a matte black finish on the layer or not. Many converting products will change the rust into a polymer that’s very dark, almost black. Others may not have any color at all. The latter can help you see what areas are treated or need additional layers of spray after drying. However, its transparency won’t cover up the rest that you treat very well.
If you don’t intend to paint, converters that change the rust’s color are recommended.
Typically, it takes about one hour for rust converters to dry, at least on the topmost layer. But you should give it at least a day for the material to completely harden. Think of it as a wood finish, except that you’re working with metal and iron instead of wood. The water that’s inside the ingredient will have time to fully evaporate this way, stopping the rust that you can’t see from making its way through the finish (or your paint, if you plan on covering the matte).
How Rust Converters Work
Rust converters are made from a combination of water and primer solution that has tannic acid and butoxyethanol as primary ingredients.
The first is what chemically alters the rust (chemically referred to as iron oxide) into an iron tannate. It’s very dark resistant to further rusting when placed into contact with water. Like butoxyethanol, it’s produced from organic materials. A protective layer is made with butoxyethanol, which further prevents oxidation from forming over the treated area. Almost all rust converters consist of these ingredients.
When to Prepare before you Spray
If you’ve read through the reviews already, then you might have already guessed that it’s important for you to know whether you intend to treat the rust before you spray. Some rust converter sprays are better suited for oxidation that’s thick, while others are better for thin layers of rust. When in doubt, always assume that the rust must be treated before applying the spray. Even a light sanding is good.
Avoiding the Odor
One of the most common complaints about rust converters spays is their strong odor. Unfortunately, you’ll be hard-pressed to find a product in this category that doesn’t have a strong smell. The best way to avoid it is by covering your nose with a face respirator or dust mask.
All work should be conducted outside whenever possible.
If you can’t do so, ensure that there’s proper ventilation in the indoor area, opening near windows and doors to reduce the strong odor. Although it goes without saying, be sure that no small pets and children are nearby the spray as well (along with pregnant women).
Knowing When to Spray
Rust converters work best when the air around the spayed material is very dry. Remember, moisture is what causes oxidation in the first place. If too much water vapor is in the air (either through fog, mist, dew, rain or high humidity levels), the converter’s effects are reduced.
You don’t want to waste your time spraying just to have the metal rust again the next day. Knowing this, time your work by checking out the weather on the day that you intend to restore the material. Avoid spraying in the mornings too since this is the time where dew and condensation are at their highest. And if it’s raining outside, hold off until things are dry!
Which of the five products shown in the reviews looks promising? Each has its benefits, performing great at transforming rust into a workable polymer surface. Truthfully, you could choose any and come out with good results. But the Rust-Oleum Automotive 248658 and Permatex 81849 Rust Treatment earn top marks for easy application on thick or thin rust.
- Coat permanently dries in about 24 hours
- No chipping or flaking once the solution hardens
- Gets flat enough