Why do stainless steel grill parts rust? This is another question we get asked all the time and there are almost as many answers as there are gas BBQ grills. I meet customers who purchase a stainless steel barbecue grill with a lifetime guarantee because they no longer want to buy a new grill every two years. They feel tricked a year alter when the barbeque grill parts are pitting and rusting. There are a lot of answers to this question but most of them are simple and sometimes obvious.
One reason is the quality of the grill parts. We know restaurants and resorts cannot waste time buying a new grill for their kitchen every few years so we assume if we purchase commercial quality items we can get the same level of quality as professionals. When an inexpensive barbeque is named the Commercial Model or Professional Series, they are usually hiding poor workmanship and cut corners with assumptions about quality based on the appearance of stainless steel. Add a few hundred dollars profit to the price and the customer gets tricked. I have seen this in many industries when the terms “commercial” and “professional” get used as the name of a product model rather than a true description of the quality of the product.
Many of these manufacturers will use a low grade stainless steel to further the association with commercial quality. Many of us do not realize there are many different types of stainless steel. Stainless steel mistakenly becomes symbolic of high quality and long lasting parts. I cannot tell you how often a buyer will walk into my retail store claiming they want a stainless grill. In their mind, they have asked for a particular level of quality using the term “stainless steel”. Many homeowners associate stainless steel with high quality. Many stainless steel types are only fit for indoor use.
Look at who makes the grill – not the importer but the actual manufacturer. Barbeque grills that are made in America will generally disclose the type of stainless steel that has been used. If the manufacturer is providing a warranty, call them and see if a human answers or if the warranty is a sham. When we purchase an American Made stainless steel BBQ grill, we spend a lot more money and have much higher expectations of the product. Contact local dealers and find out if local professionals who repair grills recommend the product.
Commercial products do not say “commercial” on them and restaurants or resorts do not buy their appliances at the gigantic retail exchanges that advertise the lowest price in town. I have clients who purchase a $300. grill and feel they have spent a lot of money. Pay attention to the type of stainless steel used by the manufacturer. Keep the grill covered and clean it as often as possible.
Today, well built products are manufactured from a stainless steel designated as 304. Stainless steel is classified in numerical categories and 304 refers to outdoor stainless because of its chemical properties. In order to be considered 304 stainless steel not only are iron oxides drained to such a degree that a magnet cannot hold it but nickel and chromium are added during the smelting process in amounts of 8% nickel and 18% chromium.
Chemicals added to stainless steel protect the material in its specific application. A different stainless steel is used for an indoor refrigerator that does not contend with humidity, rain, snow or heat. Outdoor gas barbeque grills use 18 gauge 304 stainless steel because of the nickel and chromium. Nickel is a hardening agent. Nickel is added as a hardener. When stainless begins to rust it shows up as “pits”. When oxidation begins a small rust spot will appear at the weakest parts of the stainless as a pit. As a hardening agent, nickel will usually stop this from starting.
Chromium protects the surface of the stainless steel in the same way that oil protects a cast iron pot. Chromium reacts with oxygen in the atmosphere and creates a barrier at the surface of the stainless steel. Because chromium is inside the material itself, chromium will rebuild the protective coating after stainless is sanded and polished to remove rust spots. Chromium is added during the smelting process so scratching-out rust does not remove the protective effects of chromium.
Mid-range barbeque grills like Weber and Broil King use combinations in manufacturing. Much of the stainless is decorative but generally the burners, cooking grates and heat shields will be better quality. This is because the inside of the grill gets wiped down less and gets a whole lot messier than the hood.
For the very expensive grill that has a lifetime guarantee against rust, the reason your grill is rusting is grease. I have seen DCS grills over twenty years old without a single pit on the outside of the barbeque but the burners have been replaced six times. BBQ grill stainless steel hoods will discolor from heat built up within. When the grill shows rust, it is the burners, heat shields, rod trays, cooking grates, etc. The grill parts inside the firebox get grease and drippings and carbon discoloration from heat. All of these things combine to coat the stainless and stop the chromium from reacting with oxygen in the atmosphere.
Every year I remove the burners, cooking grids and shields from my marbeque. I clean – really clean – the inside of the firebox and I clean the parts I have removed. I have a wire brush that attaches to my drill and I scrub the grates, burners and even the firebox with that brush spinning at 60 miles per hour. It does a great job and the stainless looks great until I cook on it again.
I have not seen a full size barbeque (as opposed to portable units) for under one thousand dollars that used good quality stainless steel as quality materials are more expensive. They know the decoration allows the assumption regarding quality to be made but no one who sells grills will point this out. Either accept that you will have to buy a new BBQ grill every two years or start buying replacement grill parts. Next time you buy a barbeque in the same price range, get an aluminum grill that is made in America. Pure aluminum will last forever.
Often, the best tool to fix a problem is education. Once we understand a problem, the solution will show up in our normal actions. Once you know the chromium needs oxygen to protect your stainless steel your regular post-grilling habits may change. Once we know oxygen reacts with chromium, we can degrease the stainless surface.
The gas grill can be affected by its placement relative to landscaping, pool, toy boxes and chemicals. Pool chemicals can cause the grill to corrode if in direct contact with high quality stainless steel. Pool chemicals, golf course fertilizers and some cleaning supplies will cause rust, discoloration or corrosion to stainless steel. When chlorine and other chemicals slowly dissipate into the atmosphere, they do so by chemically bonding to oxygen in the atmosphere. Near the pool, a shortage of oxygen atoms can cause the same effect as covering the stainless steel with grease. Chromium becomes unable to react with the oxygen in the air.
Use your barbeque often and enjoy the value it brings to your backyard. Also the heat lessens mess. After cooking, burn the grill on high or ten to twelve minutes to dry it out and then scrape the stainless. Make sure the grill is deeply cleaned every six to nine months including attention to the electrode ignitors, gas burner and heat shields. A properly maintained gas grill should last forever.