Most people agree that undercoating or rustproofing your vehicle can help protect it from corrosion and rust, and thus prolong the life of your car or truck. This is especially important underneath your vehicle, which is regularly sprayed with water, road salt, and highway dirt.
However, undercoating a vehicle can be costly.
Many would say without hesitation that the best time to apply undercoating is when you buy a new vehicle that has never been driven. Nowadays many dealerships offer undercoating and rust-proofing as an “add on” service for a fee. If you plan on keeping the vehicle for only a few years though, you might want to think about sparing the expense and not getting any undercoating applied.
The value of undercoating a used vehicle is up for debate. Some feel that all you are doing is covering up dirt and grime that already exists on the car. Others claim that applying an undercoating then can at least protect it from further exposure.
One local mechanic recommends not undercoating any vehicle that comes with factory undercoating.
Several options for rust-proofing or undercoating are available if you decide to go that route. They include:
• Electronic Method: Uses a weak electric current to stop the corrosive effects of rust. You can have these electronic devices installed at the dealership or buy them yourself. Reviews on this method appear to be mixed.
• Spraying a tar-based substance to exposed areas of the car’s underbody: Once this substance hardens, it acts as a barrier to road salt, dirt, and other debris. This method works best on new vehicles and it should be applied professionally or else it can crack and let in moisture, which in turn results in rust.
• Dripless oil spray: This is a waxy substance applied to the entire body of the vehicle. It hardens once it dries. You need to have holes drilled into your car at specific points to make it effective and it doesn’t always fill all the nooks and crannies in your vehicle.
• Drip oil spray: This is the most commonly recommended rust protection.
These products drip for about 48 hours until they dry. Because they are a thinner liquid they tend to get into more areas, but you still need to have holes drilled in your car.
• Environmentally-friendly lanolin based products: One of the advantages to using lanolin is that the product doesn’t drip on your driveway.
Wiggett’s Auto in Randolph, which offers lanolin-based undercoating, said prices vary according to vehicle type. For a sedan the cost is $92; a pickup is about $20 more.
If you don’t want to pay somebody else to do the undercoating, you can just do-it-yourself. Be forewarned though you need the right equipment, enough space, and lots of time.
Assessing the Results
Make sure the company or shop that is doing the work is using trained installers. Look for a neat and dry work area. Ask if they drill holes to apply the stuff (no, is the correct answer here).
Check to see if they have an installation manual for your make and model vehicle. When finished, check for evidence of rustproofing on the edges of the hood, trunk lid and bottoms of doors. You should be able to see a little—it’s usually amber in color and a little tacky. Make sure none of it clogs up the drain holes in the doors.
