Thursday, March 23, 2023


Rust: How to prevent it from damaging your RV

By Gail Marsh
Left unchecked, rust can quickly ruin more than just your RV’s look. Rust has the potential to make your rig unsafe as well. Here’s why: 

  • Driving over roads treated with salt or other chemicals can leave salt deposits all over the underside of your RV. Left unattended, this can lead to corrosion. This corrosion can quickly form rust on the rig’s frame and joints, potentially compromising the integrity of the coach.
  • Similarly, rust will form if your RV is exposed to sea salt (even from the air). 
  • If you pick up a rock or otherwise scratch the protective coating on your RV’s exterior and do not address it, you may find yourself facing potential damage from rust.
  • Rust can also compromise the interior of your rig. Excess humidity inside your RV can lead to rust around windows, door frames, appliances and more. If you live or spend time in a humid place, you know how quickly this can happen. 

As with most trouble, prevention is the key to ending the nightmare of rust. RV owners should:

  • Rinse the RV’s undercarriage regularly, especially if it’s been exposed to road salt or other corrosive chemicals. If your RV is regularly exposed to sea salt, it’s a good idea to rinse the underside of the rig once a month. Experts recommend adding baking soda to your rinse water to help neutralize salt’s corrosive effect.
  • Keep your RV’s exterior clean. Make frequent checks to look for bubbles and small scratches that may indicate potential rust damage.
  • Regulate the inside humidity of your rig. You can run the air conditioner to remove excess humidity, or run a fan to increase airflow. An open ceiling vent will help the humidity escape more readily. A dehumidifier can also help.

If you discover rust anywhere on your RV, you can:

  • Remove small areas of rust with a wire brush or small piece of sandpaper. Then touch up the cleaned area with a rust-inhibiting paint.
  • Ask a professional to check any large areas of rust you find, especially if it’s on the frame of your rig. Rust can weaken the integrity of your RV and render it unsafe to drive. Have it checked out before you hit the road again.



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S Davis
1 year ago

I’m surprised the article didn’t mention the primary source of rust in the midwest; condensation driven by temperature changes. In moderately humid Michigan changes in temperature cause huge amounts of condensation on the under carriage of vehicles. You can never drive your car and have it rust out from under you. I’ve had good luck with Fluid Film in preventing this.

Ronnie Bolling
2 years ago

Living less than one block from the Atlantic ocean since 2002 I can say rust was one big pain in the butt for me. A local painter tipped me off on a great product, Ospho, that transforms rust into a powder overnight. You brush it on using an old paint brush and it does all the work vs sanding, etc. The following day you just brush away the powder and prime (I like red-oxide primer the best since it alone will stop the rust from returning) and repaint if desired. Here’s a link to the stuff:

2 years ago

R-U-S-T ! A serious problem as noted. As a preventive, I have cleaned all that I can find on the underside of our class A with a wire brush and sandpaper – then basically refinishing the whole accessible underside with “Rust-oleum'” Bright Galvanizing #7584 and some visible areas with an overcoat of “Rust-oleum” Stainless Steel #7519. It holds very well, going into the 10th year now. Be sure to wear goggles and an approved mask when applying and apply outdoors on a no-wind day!

BULLETIN: breaking news: Just heard the 1 billion dollar lottery was won by someone in Michigan last nite!

RV Staff
2 years ago
Reply to  DW/ND

The one lottery winner in Michigan — if they’re a snowbird that couldn’t head south this winter, that ought to cheer them up a little. 😆 Stay healthy, DW, et ux. (Worked for an attorney for 45 years. 😉 ) —Diane at

Geoffrey R Baker
2 years ago

Boeing’s T-9 spray is a great rust neutralizer and provides a wax coating to prevent water ingress and further damage.

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