Lubrication is key to unlocking your car’s full potential! Lubricants help minimize friction between the wheels and axles, resulting in a significant increase in speed. However, race rules can vary on the type of Pinewood Derby® car lubrication that is allowed, so you’ll want to consult yours to ensure what options are allowed.
Lubricants fall into two categories: Dry and Liquid.
Dry - As the name implies, these lubricants contain no liquid and come in several varieties, usually in powdered form. By far, the most common in Pinewood Derby® is graphite. There are different types of graphite used for various purposes. The main difference between them is the purity, flake/particle size and if there are additional additives. While just about any graphite will work as a lubricant, some versions are specially formulated and work best for Pinewood Derby®.
Liquid - There are different liquid lubricants as well. Nyoil™ has been a popular option in years past, as well as Krytox™, produced by DuPont®. There are options preferred by league racers, similar to Krytox™ but with a lower viscosity leading to faster speeds. It is best to stick with a purpose-made oil as those purchased at automotive and hardware stores will be too viscus (thick), resulting in a lack of speed compared to the purpose-made oil lubricants.
Do NOT mix oil and graphite; use one or the other.
PRO RACER TIP FROM HurriCrane Racing: If your rules do not prohibit the use of oil, do so, as it is MUCH faster than powdered lubricants (including graphite). Also, oil is easier and quicker to apply and is not nearly as messy. Additionally, the car can do significantly more runs before losing speed compared to powdered lubricants.
Applying Oil
Getting the most out of oil is not as involved as graphite. Methods of oiling the car will vary slightly depending on the type of oil used; unlike graphite, it IS possible to over-oil. Using too much can SLOW the car down; therefore, follow the directions supplied with your choice of oil.
Generally, oil application is as follows:
Cleanliness is essential when using oil. Any bit of dirt or lint that makes its way into the wheel bore or under the axle head will slow the car. Thoroughly clean the axles and wheels and, if possible, blow them off with compressed air.
Insert the axle part way into the wheel bore.
Apply a small drop to the axle shaft and a small drop to the axle head. Twist the axle to distribute the oil along the shaft and head. A slight shake will help remove excess oil.
Insert the axle into the wheel bore and give the wheel several slow spins with the axle head pointing toward the ground.
The axle/wheel is now ready to install on the car.
As mentioned before, cleanliness is vital with oil, so once the car is assembled, wipe away any excess oil on the wheels, place the car in a sealable (zipper lock) bag, and store it safely. The sealable bag will ensure no contamination and reduce the potential evaporation of the lubricant.
Applying Graphite
Some first-time racers will apply a couple of puffs of graphite to their car before the race and call it done. While this is certainly preferable to no graphite, it is not optimal. Getting the most out of graphite is a several-step process.
Known as burnishing, you’ll be crushing/embedding graphite into the plastic, creating a thin layer of graphite. Graphite works best when applied in multiple layers, so you’ll repeat these steps several times.
PRO RACER TIP FROM Mojo Racing: Graphite can be very messy; put newspaper or another similar cover on your workspace when using it. To remove graphite from the car body, table, and other areas where you don’t want it, use isopropyl alcohol or WD40.
Steps for applying graphite:
Outer Hub: Use your preferred method to hold the wheel in a power drill. Sprinkle a cotton swab tip with graphite. Spin the wheel and press the swab into the outer hub. Run the drill for about 1 minute. Apply more graphite to the cotton swab and repeat 3 - 5 times.
Inner Hub: Flip the wheel and repeat the above steps for the inner hub. If using a rail riding setup, burnish graphite onto the inner edge of the tread on the front wheels only. Burnishing graphite on the edge of the rear wheels will foul the actual tread and lead to an unstable car.
Bore: Fill the wheel bore with graphite. Insert a polished pin or polished axle. Gently roll the wheel forward and backward on a towel or similar surface while applying downward pressure on the pin. Do this for a minute or two, and repeat this step 3-5 times.
Do NOT apply graphite to the tread, use isopropyl alcohol to remove any graphite from the tread.
Body: As mentioned in the Body article, apply graphite to the car body at the axle holes using a cotton swab.
OPTIONAL: For extra speed, burnish graphite onto the axles as well. Sprinkle graphite onto a soft cloth, insert a polished axle into a drill and turn it slowly while pressing the cloth/graphite to the axle. Do so for 1 minute, 3-5 times.
Inspect: After applying graphite to all areas (wheels, body, axles), inspect and remove any lint left by the cotton swab or cloth.
PRO RACER TIP FROM JBD Racing: For an extra burst of speed, lightly dust the cotton swab/cloth with Lemon Pledge Furniture polish before sprinkling the swab/cloth with graphite. The polish’s silicone helps bind the graphite to the wheel and makes a very slippery surface!
After Car Assembly:
Once you have assembled the car, adding graphite to the wheels again is good practice. Place a small amount of graphite on the sides of the axle head. Gently tap the wheel to encourage the graphite to find its way under the axle head and into the wheel bore. Turn the car so the wheel faces the ground and spin the wheel several times. Repeat this process with the inner hub. Apply graphite and tap the wheel to spread the graphite into the inner hub and between the wheel and the car body. Turn the car so the wheel faces up and spin it several times. A soft bristle paintbrush works well to push graphite under the axle head and onto the inner hub. Add more graphite and repeat.
Graphite will wear and start to lose its effectiveness over several runs. Therefore, always add more graphite after test runs, and if you can re-lubricate during a race, do so!
Storing the car
Once assembly, lubrication, and tuning are complete, it is best to store the car in a zipper-lock-style plastic bag to prevent dust from contaminating the wheel bores and axles. Additionally, place the car body on a block of wood or similar so the wheels do not bear the car’s weight. This prevents flat spots from developing on the wheels!
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