Removing Fluorocarbons…

Some wax/service questions seem to pop up with regularity. One of the regulars just showed up in my inbox courtesy of Jonathan Patz, and I thought I’d take the opportunity to address it publicly.

“We have races off and on now, and I’ve heard it’s important to hot -scape (with soft hydrocarbon) after you race — assuming your next race is  1 or 2 or 3 weeks away.  What’s your take on this?  Does the high F dry out the ski?  stress the base?   Or is this not a big deal?”

First, it’s necessary to be clear about the difference between HF paraffin and “pure” fluorocarbons. In general no fluorinated paraffin is going to damage or clog the base appreciably more than normal paraffin. You can wax nothing but HF paraffins until the end of time and your skis will probably just be fast as a result. The concern is the pure fluoros. “Pure” fluoros aren’t actually pure. They are “perfluorocarbon” compounds with additive materials to harden them and tweak the characteristics. While it’s not universally the case, these pure fluoros tend to have very high melt-points. There are a couple of ways they can foul-up the works. But there are also ways to avoid potential issues.

Problem #1 – repeated applications of pure fluoro powder mean repeated doses of very high iron temps, which can certainly damage the bases in time.

To avoid burning the bases with fluoro powder applications it is necessary to:

a – have the base well race hardened (a one-time process for a new or freshly ground ski) prior to the application of powder.

b – Use sufficient powder to allow the fluoro compound to flow easily.

c – Use sufficient heat to allow the fluoro compound to flow easily.

Problem #2 – High melt point fluoros in/on the base will not mix well with normal (lower melt point) paraffins when you try to rewax the skis. This can prevent the wax from dissolving into (penetrating) the base.

To avoid “clogging” the base with fluoro compound I prefer to use a fluoro solvent like Holmenkol Nano-CFC cleaner, Star Fluoro Cleaner, Swix Glide Wax Cleaner, or Maplus Fluorclean. Those are the ones I have used and tested the most. These products are actually solvents for the fluoro compounds that can foul up the works. I have had good success using all of these products by wiping them liberally onto the base, working them with a nylon (or even steel)  brush, and then letting them dry, and brushing away the residue. For a heavy application of pure fluoros it is sometimes necessary to repeat the process. After that the skis are easy to work with.

This photo of a thin strip of base materials shows the crystalline UHMWPE sinters as the clear areas. The black web of material around them is the amorphous material where base additives live, and where wax goes into solution.

You can also use the “hot-scrape” method. This is an effective method of cleaning skis, but I don’t like it for a number of reasons. Specifically, I don’t like it for cleaning pure fluoros because the soft paraffins used can’t carry enough heat to get the fluoros to melt and mix. And further problems arise when you turn the iron up. If you use a hot iron on a soft, low-melt-point paraffin, it is very easy to destabilize the amorphous materials in the base. This will cause you to scrape black wax shavings. Very satisfying if you’ve somehow convinced yourself that you’re removing “dirt”. But that’s not what’s happening. You’re removing carbon-blacking, and whatever other additive materials are in the base. Once the base is destabilized in this way, it tends to stay destabilized, meaning that you continue to scrape black wax shavings, and the base is quick to “dry-out”, or show areas of a white filmy deposit in the high-pressure zones after skiing. This white stuff is fibrils of the low density PE material in the amorphous zones, and it shows up against the black base just the way the black additive materials shows up in the white wax shavings. Usually both are present.

The phenomenon of black wax shavings and destabilized amorphous material is a confusing one. Sometimes skis with these destabilized amorphous mterials run well, but usually they don’t. Some base materials are very prone to destabilization, and don’t seem to suffer performance issues related to the black wax shavings. Other base materials really want stability. It’s quite possible to hot-scrape skis WITHOUT destabilizing the base material, but it seems to be a matter of finding specific iron temperatures to complement the base material and the wax that you’re using.

Because it’s very difficult to provide precise instructions for a process, like hot-scraping, with so many variables, I really prefer to use fluoro solvents to clean skis! Unfortunately the very idea of using solvents on ski bases is anathema to many skiers. This prejudice is based on bad information and misconception. The base cleaner solvents are generally mild, and not astringent. They don’t go into solution in the base (a process which requires elevated temperatures), and they’re not going to “dry-out” your skis. They just dissolve the surface coating and allow you to brush away pollutants, preparing the base perfectly for a new paraffin application. Pretty cool! I use fluorocleaners regularly – a standard part of race ski preparation. But some of the waxers I have worked with and who I respect the most still swear by the hot-scrape method of cleaning.