NavList:

Air navigator's E6-B Flight and Polhemus Celestial Computers have built-in plastic surfaces for plotting wind triangles, LOP's, flight-tracks and fixes.

To facilitate plotting, their transparent plastic plotting plates are slightly frosted, enough so that they take HB and B hardness pencil lead very well.

But cleaning up plots and annotations after use can be challenging. Many types of erasers leave smudges or, worse yet, mar the surface with fine scratches degrading the plotter and making the next cleanup even harder.

While it's possible to use very fine powdered cleansers to wash graphite off, it's not a practical work-a-day solution. Cleansers are abrasive as well.

I have experimented with seven types of 'artist' erasers and some do a good job of erasing plots without leaving graphite smudges or scratching the plastic.

My unscientific tests in removing pencil plots (B hardness) from E6-B and Polhemus plotters are:

• General's TRI-TIP              mid-pressure to erase, slight smudge, no scratches
• Paper Mate's Pink Pearl    light-pressure to erase, no smudge, no scratches
• Prismacolor's Magic Rub   mid+pressure to erase, very light smudge, no scratches
• General's Kneaded Eraser    high-pressure, very light smudge, no scratches, good at cleaning old smudges
• Staedtler's Mars Plastic    mid-pressure to erase, very light smudge, no scratches
• Factis' Black 18                similar to Pink Pearl

If there is an overall winner here, I would say a new Pink Pearl is best. They are excellent on paper plots as well.  Pink Pearls will harden with age and become less effective, however. The least useful on paper plots is the Kneaded Eraser because it shape deforms like modeling clay and is less useful for precise or small area erasures.

The above erasers were available at my local art supply store. See the attached photo.

It's helps to keep erasers clean by removing prior graphite and grit (especially with Kneaded Eraser) as they will transfere their graphite back onto the plot.

This has to be the most trivial topic ever posted on NavList.  But I'm interested in what other NavLister’s experiences.

Popko

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