Re: [aus-soaring] Useful stuff

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Chain lubrication is fairly specialised.  Chains can never work in the ideal state of hydrodynamic friction but always in the critical areas of boundary friction and mixed friction.  High loads act on and are restricted to the linear surface contacts. All motion is angular, there is no rotational motion. Speciality lubricants, as opposed to straight oils, are of particular importance for the lubrication of chains.  Wear is critical as with only 3% elongation the chain will not mesh correctly with the sprocket.  Even with optimal lubrication chain stretching will occur over a long operational time but with adequate lubrication lifetime is generally 60 times longer than with dry running.    Effective chain oils need a low viscosity initially to aid penetration.  This is achieved in modern technology oils with additives - the oil initially has a very low viscosity but then returns to it's normal viscosity which will mostly be in the range 300mm2/s - 450mm2/s - much higher than engine oils. Some of the cheaper versions do this with added solvents which evaporate - so you are losing up to 25% of the total - a quick smell will demonstrate when solvents are added.  To aid penetration foaming agents are also added - the foaming actively supports penetration.  Penetration is essential to avoid dry running, stress corrosion and pitting.  The oil should also have penetration additives to aid the 'creeping' effect, corrosion prevention additives, moisture inhibitors and the latest technology chain oils use Volatile Corrosion Inhibitors (VCI) which make any remaining moisture electrolytically inert, so preventing electrolytic corrosion.  The ability of the oil to deal with moisture is critical as temperature cycles create condensation which forms on the inside of the components, in turn causing corrosion, and this is a factor in chain life.  The latest chain oils also have the MoX-Active organic moly compounds, a modern clear version of moly which is in solution and which greatly reduces surface friction and changes, by smoothing, the surface components. Then adhesive additives are required to prevent fling-off.  Chain oils will (or should) support loads in the order of 2,500N in a standard 4 ball test rig, which for those who don't know exactly what this test rig is - which will be most - it means they can take a very great load   Engine oils are OK for engines but have quite different properties to oils suitable for chains.  They are cheaper but whether you consider this economic depends on the cost of the chain and maybe it's importance.  Lanolin is not known to be good for chain lubrication.               ----- Original Message ----- From: Peter Stephenson To: [EMAIL PROTECTED] Sent: Friday, June 08, 2001 1:56 PM Subject: Re: [aus-soaring] Useful stuff What about this new lanolin product that is so good that it is short supply? PeterS > > lubrication of chains, sliders and bearings in difficult locations. "Sound > > familiar".  It is designed to stick like "shit to blanket" and I think it could be > > useful for lubricating all those hard to get at bearings in glider --   * You are subscribed to the aus-soaring mailing list.   * To Unsubscribe: send email to [EMAIL PROTECTED]   * with "unsubscribe aus-soaring" in the body of the message   * or with "help" in the body of the message for more information.