[s-cars] Re: [audi20v] Re: what paint for coil springs

[David Mackintosh]

I believe any typical paint/powder coating is going to have plenty of flex.
Even chrome plating has been used on coil springs and I don't believe it's
much of a problem.  

Note that coil springs work purely in torsion.  If you look at the equation
for calculating the spring constant, it comes down to calculating the length
and the torsional resistance of the wire.  As a progressive spring is
compressed, the number of free coils decreases, which shortens the effective
length of the wire (increasing the spring constant).  

The springs are in a pretty harsh environment due to wheel spray, stones,
etc.  Also, where coils meet there is relative movement which will probably
abrade any finish eventually.  Surface rust will form, but this shouldn't be
a problem, except for cosmetically.

David Mackintosh
mackintosh at gorge.net
541-400-6300 (cell)