WD-40, WAS Lubrication of gravity arm latch where it engages the gravity arm?

andrew_emmerson@btopenworld.com <andrew_emmerson@...>

The perils of WD-40 came up recently in another forum. The following may be of interest:


> > I quote (from an industrial chemist on the Boatanchors radio forum):
> >
> > *WD-40*is a product to use with some care. The version sold in aerosol
> > cans is made of around 50 per cent Stoddard solvent (a refined
> > kerosene), about 15 per cent petroleum-based oil (actually a
> > paraffinic solvent-refined mineral oil), 25 per cent LPG (isobutane
> > and propane liquefied petroleum gas) and 10 per cent of a proprietary
> > corrosion inhibitor. This makes it pretty flammable and calls for
> > thoughtful use. Its original purpose was as a water-displacing
> > compound (hence the initials WD); the Stoddard solvent gives it a low
> > surface tension, which allows it to penetrate small cracks and
> > crevices. After the kerosene has evaporated, the oil is left along
> > with a little corrosion inhibitor.
> >
> > For car engines and industrial machinery, WD-40 has a
> > number of applications but in domestic electrical apparatus, many of
> > its properties are counter-productive. The oil in it has some
> > limited lubricating properties, but it does nothing to clean oxidised
> > switch contacts and acts as an insulator. The only way it can protect
> > a surface from oxidation is by physically covering it. And like all
> > paraffinic oils, it attracts dust and reacts slowly with oxygen in the
> > air to cross-link and polymerise, producing the well-known ‘gummy
> > mess’. As an insulator, it can lead to carbon arcs tracks on switches
> > and electrical contacts. As a cleanser it has some effect; the
> > kerosene dissolves old grease but it is not suitable for electrical
> > contacts or carbon potentiometer tracks.

I would add that WD-40 is also notorious for starting off the slow disintegration of certain plastics, a process that does not manifest the full effect for ten years or more. Truly, WD-40 has no place in our workshops.

Andy E.


From: synchronome1@groups.io <synchronome1@groups.io> On Behalf Of John Hubert
Sent: 15 April 2019 21:51
To: synchronome1@groups.io
Subject: Re: [synchronomeelectricclock] Lubrication of gravity arm latch where it engages the gravity arm?


WD40 is a ‘water displacing’ fluid.  It leaves a nasty gummy residue as the solvent parts evaporate.  It is this that prevents corrosion.  


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