Undrdog The Purps Iron and Fallout Remover: Undrdog Surface Products

When removing decontaminants from your car’s paint, there are two main ways of doing this. There’s the mechanical method, which involves removing contaminants via something like a clay bar. This mechanical method physically removes small particles embedded into the clear coat or paint. The other decontamination method is the chemical method via an iron remover.

If you did not know already, an iron remover basically accelerates the oxidation process of ferrous (iron) material. When it does this, it breaks the iron material loose from the surrounding clear coat so that it can be rinsed away afterwards. The chemical reaction of this happening leads to the purple ‘bleeding’ effect that you see after you spray on the iron remover onto your car.

You’ll find many iron removers made by different companies, but they all do the same thing. Undrdog Surface Products has own iron remover called The Purps. It comes in a 16 oz, 32 oz, or a gallon (128 oz) container, with the gallon size offering the best discounted price. To provide full disclosure, Undrdog supplied this product to me for this review.

I tested Undrdog’s The Purps Iron and Fallout Remover on our family minivan. The previous owner who purchased it new, owned it for several years before selling it to us. Iron removers work great on used vehicles, but they still have their use on even brand new vehicles.

Prior to applying the product, you want to make sure the entire vehicle is clear of as much dirt and gunk as possible. If your car is extremely dirty you can start with using a pressure washer along with a foam cannon and snow foam as a pre-wash (i.e. spray on snow foam, let sit for a few minutes, and rinse off.) However, a pre-wash is not totally necessary—it just helps with cleaning the car if it is extremely dirty.

Next, I recommend using the two bucket wash method to thoroughly clean the surface of the vehicle. This involves using two buckets with grit guards inside of each, using one bucket for soapy water and the other for cleaning off your wash mitt. The most important thing is to use a grit guard so that it can trap the dirty particles that come off your wash mitt, down at the bottom of the bucket.

The pre-wash gets more of the larger, looser debris off of the car, but you won’t get a car truly clean without using a car soap and a wash mitt.

After the soap, rinse the car down with water.

Now, you can be confident that most of the dirt and debris is off of the car. It is now time to apply The Purps Iron and Fallout Remover. Using this product is super easy. Use the spray bottle to spray the product all over the entire vehicle. You can even spray it on the wheels as well.

A word of caution, iron removers have a very bad smell. The smell comes from the main ingredient, thioglycolic acid, which is basically what you’d smell at a hair salon (they use the same ingredient to straighten hair.) The odor is not uncommon and something you should expect if you use any iron remover product.

Also, iron removers can be a eye, nose, and skin irritant. I recommend using some PPE (personal protective equipment) if you are able to. I normally use a mask/respirator when I use this product because I know when I don’t, I usually react with a runny nose afterwards. Others may react differently, but ultimately it’s best to protect yourself when using this product.

Undrdog suggests letting the product sit for 2-5 minutes before rinsing it all off with water. Absolutely do not let this product sit on the car longer. If you do, you risk this stuff leaving marks behind on your car, which won’t come off for a long time. If you’re applying this product in sunlight and/or it is a warmer day, err more on the side of 2 minutes.

I know you can become entranced watching the purple-bleeding effect, but don’t let it sit too long or you’re going to have a hell of a time removing it later on.

After 2-5 minutes, thoroughly rinse down the vehicle with water.

And it’s as simple as that for using Undrdog’s The Purps. If you are doing more decontamination via the mechanical process, now would be the time to bust out the clay bar. Otherwise, dry off your vehicle and you are finished, knowing that your car is clean and the iron decontamination is complete. If you want to read up more in-depth on the iron decontamination process, check out this guide to performing an iron decontamination.

Undrdog’s The Purps Iron and Fallout Remover does what it is supposed to do. After spraying it onto the car, the iron is worked loose from the car’s surface and allows you to rinse it off using water. It does the job well, and I don’t have any complaints about the product.

It smells very bad, which is to be expected with any iron remover. At the time of this writing, the price is pretty much on par with the others in the market, although Undrdog always seems to be offering promos, which allow you to score a deal on their products from time-to-time.

Undrdog The Purps Iron and Fallout Remover: Undrdog Surface Products


Hi there! I'm Scott and I run The Track Ahead. My goal is to provide helpful articles and tutorials based on my experience and research related to car maintenance and automotive detailing. When I'm not writing and not working my day job, you can find me spending time with my family and working on home and car projects.

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