[s-cars] RE: Best Wipers, follow-up considerations

[CyberPoet]

As is often the case, I forgot a few things.

1. Pressure changes. You can increase the strength of the spring that
holds the blade on the windshield by lifting up the arm, removing the
spring, giving it an extra turn (or removing one) and then reinserting.
This helps by really heavy snow/rain, but is not as good as solution #2.

2. Wiper Arm Wind Deflectors. They are to be found in every German
autoparts store I've ever walked into (as well as most gas stations
there), but I have rarely seen them in the USA -- and never without
their being excessively gaudy (lime green and 3 times too large?). The
standard euro ones clip over the wiper arm and add down-force from the
on-rushing headwind, thus permitting a streak free wipe even at
autobahn speeds. Cost: about $3.50 in country. Value: about $25 when
you need 'em.

=-= Marc Glasgow


> The definition of the best wiper blade coheres with the type of
> environment you plan on needing them in, and your definition of best
> (longest life or highest effectiveness?). Generally, your questions
> can be answered by viewing the new blades at the auto parts store from
> the end to determine thickness. Before I start talking tech, let me
> explain a few terms for the uninitiated:
>
> Blade edge -- the thinnest part of the blade, the portion that rests
> against your windshield.
>
> Blade Triangle -- if you look at the wiper sideways from the end, you
> will notice that the blade edge traditionally sits on the apex of a
> triangle of material (usually a rubber-plastic compound), with the
> opposing side of the triangle formed to connect to more of the same
> material. This triangle of which the front edge is the blade edge is
> the Blade Triangle.
>
> Blade Pivot -- if you look at the wiper sideways from the end, you
> will see that the back of the blade triangle (the flat side opposite
> the blade edge) is connected to the rest of the support with a
> narrowing of the material between the blade triangle and the
> remainder. This narrowing is there to permit the edge triangle to
> pivot as the wiper changes direction. This is the pivot I am talking
> about and not the one at the mounting bracket.
>
> Indent -- the indent is the amount of material difference between the
> maximum width of the blade triangle and the minimum width of the blade
> pivot. A larger indent makes for a loser pivot, if all other things
> are the same.
>
> Now for the recommendations:
>
> For snow and ice-bound situations, especially with dirt/salt mixtures,
> use the thickest contact surface blade you can get, with a thick blade
> pivot (minimal indent), since flex isn't nearly as important as wear
> and ability to push.
>
> For light to medium clean or acidic rain, use a medium-thickness blade
> edge with a medium pivot (medium indent). Most blades fall into this
> category. Specialty blades in this category include silicon and teflon
> stripe blades.
>
> For medium to heavy rains, and rains in locations with high
> calcium/lime contents (such as most of the southeastern USA), use a
> very thin edged blade with a thin pivot (large indent). Bosch
> MicroEdge wipers are particularly good for this scenario. Naturally,
> thin-edged blades tend to not last as long as thicker-edged blades,
> but they form a tighter bond to the glass (the pressure from the
> spring in the arm being the same at the blade mount, and less surface
> area being in contact with the glass) and thus do a better job of
> wiping away water, and water bearing residual mineral content before
> it calcifies/hardens.
>
> Hope that answers every possible question you could ever have about
> wiper blades.
> Cheers,
> =-= Marc Glasgow