What if my Lunchbox has rust on it?

We understand that you want your PlanetBox to look spot free so we’d like to explain where spots can come from, why they are harmless, and how you can remove them.

If you have staining on the lunchbox lid in the areas where the magnets are placed, it is because the magnetic material from the back side of the magnets is rubbing off onto the box.   This happens if your box or magnets are not completely dry when you place the magnets on the lunchbox.

The discoloration is only cosmetic damage.  The blemishes do not affect the functioning of your PlanetBox and the marks can be cleaned off.  What can be done to fix this is cleaning off the rust, switching to a new set of magnets AND always making sure both the magnets and lunchbox are totally dry before putting the magnets on the box lid each time you use it.

The marks can be removed by doing the following (photos below):

1)  Gently scrubbing with a fine steel wool


2)  Making a thick paste of vinegar and baking soda, leaving it the marks for at least an hour and then scrubbing it off and rinsing.

These methods may scratch the stainless, but any scratches are purely cosmetic and harmless.  There are no “coatings” on our stainless to rub off – the boxes are pure stainless steel inside and out.


On rare occasion we have heard from customers that their PlanetBox is ‘rusting’. They say that what appears on the surface of the lunchbox (usually on the top lid) is rust and it does not wash off.  We have replaced a number of these lunchboxes now and in all cases what is present may indeed be rust but it is not the rusting of the actual lunchbox which is to blame.

PlanetBox is made from high grade stainless steel. This type of material is highly resistant to oxidization (rusting) of the base steel by virtue of the inclusion of other metals, namely Chromium and Nickel.  The alloyed metals serve to resist the degradation of the iron in the steel that can come with exposure to atmosphere and in particular, water.

Where do spots come from:  If there is a spot on your PlanetBox, it is most likely due to either:

1) A mark left behind from the electropolishing process, which smooths the surface of the metal and makes it shiny.

2) Detergents that contain chlorine bleach.  Bleach causes pitting and “eats away” at stainless, and should never be used to clean our products.  Common detergents that can contain bleach include many “Cascade” dishwashing products, as well as other brands.

3) Hard water can leave dark spots and stains on your stainless.

4) Magnetic material left from the magnets on top of the PlanetBox, especially if the magnets are accidentally left on during washing

5) Foreign material can attach itself to the lid of the lunchbox and then can proceed to corrode in place. This likely happens when customers wash their PlanetBox with other carbon steel items in their dishwasher or sink. Sharp kitchen knives are a potential culprit, as are rusty baking pans. These little flecks of iron or other contaminants attach themselves to the lid of the lunchbox.  After these bits of foreign debris attach themselves to the lid they proceed to rust. If these are left unattended for a very long time they can begin to ‘pit’ the lid of the lunchbox, making very tiny divots in the surface.


The good news is that spots can usually be removed easily.

Corrosion Spots

Corrosion spots can be easily cleaned up with either some super fine steel wool and a little elbow grease, or a paste of baking soda and vinegar.

Fine Steel Wool Method: 

Start by washing your PlanetBox very well under running water. Then take some Super Fine Steel Wool (#000 is one such ranking) and start by lightly buffing the spotted area. Often times it just takes a few strokes under light pressure to remove the spots. If that doesn’t do it, then proceed to work the surface harder with the steel wool pad. This may cause very minor scratches to the surface of the lunchbox, but the tradeoff is that it will almost always remove the offending spots – with no damage to your lunchbox. Rinse with running water as you are going and within no time you’ll have a shiny new PlanetBox to use and enjoy for years more to come.

Baking Soda and Vinegar Method:

Make a thick paste of baking soda and vinegar, and leave on for at least an hour.   Try scrubbing it with a sponge and/or some fine steel wool.  Rinse and dry.


Hard Water Spots

Hard water has a high mineral content. If it is used to wash stainless steel, then left to set, the water will evaporate and leave behind minerals, such as limestone, which can appear as white spots.

To avoid hard water stains, always rinse your PlanetBox after washing, and immediately dry using a clean, dry cloth.

To remove hard water stains you can try placing a vinegar-soaked rag over spots for a short period of time, and rinsing and drying promptly.  If you are using a dishwasher, place 3 cups of vinegar in first wash cycle and repeat for the next several washes.

Below are photos showing how to clean spots off your PlanetBox product.

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