How to Seal Pinewood Derby Axles
We will discuss why it is important to seal your polished axles
Making BSA axles into speed axles is an art and process. You have to have very specialized tooling to do it correctly as well as efficiently. This is the method that we followed and then tweaked to our liking. I will update As I go. Lots of info to process here. Check back often
Why do you need to seal your axles? A sealant is used to protect the raw metal so that it does not oxidize (rust) because after all the axles are made of iron. If you strip the zinc coating, you need to protect your axles so they will not rust. If your derby car is out in the shop, you have the potential to expose the highly polished surface to the moisture as quickly as over night. Pictured below is rust that formed within 34 hours without sealant. That axle was wiped clean with alcohol prior to testing. This moisture will rust the surface of the axle. You will no longer have that high polished axle and you will have an increase in friction. After you did all that work, ever wonder why your car still runs slow?. Don’t chance ruining your axle. Seal it! Believe it or not, just think about it.
When choosing a sealant, it is more important to know if that substance is harmful to your wheels. The easiest way to find out is to spray some on the outer surface of a BAD wheel and test it.
WHATEVER you do, do not use WD-40. It will melt your wheel. Maybe not instantly like other solvents, but within the hour, it will. Do not use it as a lube, do not use it as a sealant.
We tested many wet to dry applications as most pack rules require use of dry lubes.
A sealant usually has a wax of some kind. It will go on wet, dry to touch. It will contain chemicals that will inhibt the corrosion process. As stated before, you need to test this on the surface of the wheel to make sure that it will not harm the wheel as it is doubtful that it will harm metal surface. Below is a list of known substances we have used and tested. Our goal was not to find which sealant will last the longest, rather which sealant will work best with dry lubes. Which will not gum the dry lube, which will not wear off after a few races.
Placing chemical on wheel, we tested for compatibility at 15 minutes, 30 minutes, 1 hour, 3 hour, 12 hour, 24 hour. We listed the findings in the table below. IF sealant passed wheel test, we then tested on axle for durability.
Testing for sealing, we place chemical on axle as directed by manufacturer, then allowed to set in uncontrolled environment (garage)for 1 week, recording results on a day by day basis. Axles were prepped to 2000 grit surface area. Control had no sealant.
However, our axles are sealed with proprietary sealant that allows us to coat an axle with Krytox in a dry format. Very similar to Teflon coating on a pan. Why did we choose to do this? Simply we could not find an over the counter sealant that we liked paired with our graphite. We needed a sealant that would not leave a waxy substance that would gum up our graphite once we started our break in process.
Did we go overboard? Maybe. But if you view our feedback, it seems that most people like it.
IF you would rather purchase a set of our sealed axles visit our store