Younger than Hack
Yes that is white gas. The advantage to it is that it has no added junk. It dissolves the old oils and chain lubes wax type included and then when you remove the chain from the gas the remaining gas evaporates and there is nothing left behind to affect the new lube.Grape, this sounds great. I will definitely try this over the Winter on my first rebuild. Just to be clear, white gas is the stuff for camping stoves like a Coleman right?
WD40 is a blend of petroleum based solvents(about 50%), mineral and natural oils(about 25%) and CO2 for propellant(about 25%.) Yes, it will dissolve grease and oils very, which is why it works so well as a cleaner. If you do not wipe the chain down afterwards, you are right, the remaining wd40 will thin/dissolve any synthetic or dry lube you apply to the chain. However when properly wiped down, the chain can be re-lubed with an oil based lube no problem. It does not harm the chain. WD40 was originally designed to repel water and prevent corrosion. That said, excessive use of wd40 will remove grease and oils that prevent wear on moving parts. I usually spray a cloth which i use to wipe the chain.
Hophead is correct. The places we want lube are between the plates and on the rollers of the chain. White gas will clean those spaces out and evaporate allowing for a clean fresh surface for the new lube. WD40 will get in there and clean out the old lube but it will not evaporate, wiping down the chain will only remove the WD40 on the outside, but the important place between the plates and on the rollers/pins will still have WD40 and it will continue to eat at the new lube. While WD40 is classified as a cleaner, water displacer and lubricant it is not designed for areas that are under high stress as the rollers/pins it will do ok for the space between the plates as they don't have a lot of stress on them but it is not the ideal lubricant even for that area. The WD40 removes the good lube and will supply a bit of lubrication but not enough and will cause the chain to wear prematurely and cause chain suck to occur long before it would with a good lube down in between the plates.I would not recommend using WD40 on bicycle chains and here's why.....
WD40 will work to clean a chain, but was designed to displace moisture and is quite good at it. WD40 is very persistent and will remain in the nooks and crannies of your chain which is not what you want. Since it is also a solvent, it will do it's work on the newly applied chain lube just like it did on the old stuff.
To clean an old nasty chain, use one of the many products out there designed specifically for that purpose. A chain cleaning tool like the Park CM-5 is nice to have too. Use it with soapy water or a citrus based cleaner.
Seriously, if you switch over to R&R lube, your days of greasy, grimy, cruddy, chains will be over. The stuff really works!