Sound reasons for undercarriage car rust prevention

Rust prevention is a greatly debated subject with many car owners refuting any claims on the value of it's application. However, for those owning a car for more than 8 years or classic car enthusiasts, this discussion changes to one of agreement. Visit any auto forum group and you are bound to read posts of car owners having had to fork-out a few £1000's to have their car treated for rust. Rust prevention is a matter of choice, but for those who plan on keeping their car beyond 8 years, there is definitely value in applying an undercarriage wax.

The first reason valuing undercarriage rust prevention is the presence of salt on our roads during the winter months. Salt is a major contributor to corrosion. Salt lowers the freezing point of water causing ice to melt even when the air temperature is at or below freezing. While this keeps the roads safe, over time it can have a damaging effect to an unprotected undercarriage.

Rather than wait for the damage to happen, the best solution is apply rust prevention oil or wax product that will "creep" into cavities you can't reach directly and which will repel water. There are drip holes in the bottom of car doors to allow water which gets in past the window seals to run out. Use those holes to spray a rustproofing using a spray can.

Undercarriage rust prevention with DINITROL

DINITROL underbody wax provides long-term resistance against corrosion and abrasion, even under difficult conditions such as frequent driving over rough terrain or gritted roads. After application, the solvents have evaporate leaving a tough elastic black waxy protective film, giving a high degree of protection. The film is also heat resistant and retains its adhesion to the undercarriage at all usual repair and paint oven temperatures. 

Rust prevention waxes are applied by either brushing or spraying them on. Dinitrol rust prevention waxes will skin over the applied area remaining soft to the touch. The test is to put your thumb onto the surface of the wax and it should leave a thumb print but you should not have any wax on your thumb. The skinning process allows for expansion and contraction. If a stone should bounce up and break the underbody wax surface skin, it will migrate back across the gap left in the wax by the stone thereby continually keeping moisture out and preventing the onset of rust to the undercarriage.

To ensure maximum protection and adhesion a very thin coat of cavity wax can be applied prior to the underbody wax application - basically wet it to seal the surface and improve adhesion. If this coating is too thick it can make the cure process much longer. The solvent will evaporate over time.

If small stones or grit get into the surface of the wax it will not affect the rust prevention properties of the wax. It dries to a tough elastic waxy coating giving a high degree of protection. Rust prevention waxes and oils lock out moisture!

DINITROL rust prevention products

• DINITROL 4941 - black, tough, elastic and waxy film

• DINITROL 4942 - brown, tough, elastic and waxy film

• DINITROL 4942M - brown, tough, elastic and waxy film with higher solid content - lower VOC

• DINITROL METALLIC - brown, tough, elastic and waxy film - does not harm rubber or plastics

• DINITROL HP - high performance, clear, allows paint colour to show through

For guidelines on how to apply DINITROL rust protection products >>