re: WD-40

[P3D <bd3d@xxxxxxxxxxxxx>]

Someone asked about constituent components of WD-40.  The MSDS I have shows about 70% Stoddard 
Solvent (this is the low-viscosity evaporative carrier), 20% heavy paraffinic oil (this is the lubricant) and 
smaller quantities of fragrance and a proprietary corrosion inhibitor.  

In my opinion, it is the paraffinic oil that makes this product unsuitable for camera work.  After the solvent 
has evaporated you are left with a relatively viscous ( >100 S.U.S.) oil which will inhibit motion rather than 
enhance it in things like shutters.  This oil would be similar to 3-in-One household oil or sewing machine 
oil.

The question was raised about pH of this product, and whether corrosion inhibitor was acidic.  If you 
remember your HS chemistry, pH is applicable to water solutions, not oils.  Possibly a TAN (total acid 
number) would give you a better idea of what you are looking for, but most of the water-based corrosion 
inhibitors I deal with are alkaline and function chemically.  Oil-based ones tend to be waxes or similar that 
inhibit through barrier process.

My 2 cents.

Best regards,
Bill Davis, with suspicious address problem solved.
mailto:bd3d@xxxxxxxxxxxxx




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