After reading some of the purported benefits to using a a waxed chain, as opposed to a liquid ("drop on") lubricant, I wanted to give it a try. This week, I made my first attempt to wax the chain and clearly my efforts did not live up to my expectations, as shown in
this photo of my now rusty chain after only 5 days of use.
To summarize my process, which mirrors other procedures I found online:
I started from a brand new chain (KMC X9.93) and cleaned it by soaking it in mineral spirits for about 24 hours, then soaking it in isopropyl alcohol for another couple of hours, and finally dried the chain before proceeding. I used ordinary paraffin wax (new, clean, white/clear) without any additives (such as PTFE or MoS2, etc.) and melted it in a water double-boiler at roughly 90 °C. Once the chain was cleaned and the wax was melted, I dipped the chain into the wax and agitated it around a bit. A few air bubbles were observed to come off the chain once it was in the molten wax, which I attributed at the time to be trapped air escaping from the small joints between links that was previously 'frozen in' by a thin layer of solid wax that formed immediately after placing the relatively cool metal (acting like a heat sink) into the molten wax. After about an hour of letting the chain rest at the bottom of the pool of molten wax, I lifted the chain out and let it drip for a short time, then set it down to allow it to cool to room temperature. Afterward, the chain was very stiff and I methodically loosened each link by hand to ensure it would move freely. In doing this, little bits of wax did fall of, as expected. I installed the chain on the bike and then rode it around for > 8 miles to 'break it in.' During this break-in time, I noticed that it was not shifting well and would lag behind the gear it was supposed to be in as I moved up/down the ramp, but I did not change anything during the break-in period, or the next day, in case it would self-adjust back to normal. It did not go back to shifting well, so I loosen the derailleur a small amount, which made it shift nearly perfectly.
After installing the waxed chain (and the derailleur adjustment), I had several consecutive days of commuting through the rain as well as rain on my bike while it was locked at an outdoor bike rack, while seemingly the chain performed fine. Today was my first dry day and I took the time to actually get down and inspect the chain closely, which is when I found all the rust (see photo, linked above).
I expect paraffin to be long-lasting and extremely hydrophobic, not only to repel water quite well but also to resist being washed away by water, and to last at least as long as liquid-based lubricants (if not substantially longer). The exterior parts of the chain (where nothing rubs), where some bits of way are still visible, looks fine (clean and rust-free). However, the interior surfaces and joints, where there is a lot of rubbing (chain-on-chain and chain-on-cassette) are very rusty. It would seem as though the wax came off these regions and left the metal unprotected. Also, I noticed that the cassette, which was also brand new at the same time as the chain, is also covered in darks splotches of material, which I am guessing are bits of dirty wax that came off the chain. Why is this happening? Why didn't the wax stay adhered to the chain? What could/should I have done differently?