SF-20 Maximum precision Tempered glass file

The DSPIAE SF-20 glass polishing file

A file of tempered glass with a very fine working texture. It does not remove material the way a conventional file does but smooths the surface, so it belongs at the end of the procedure rather than at its start. Against metal, glass has the property of not clogging as fast, not corroding and not dirtying light-colored plastic with rub-off.

The larger version

The SF-20 is the longest version in the range: it has a larger working face and a longer section to grip. In practice that means two things. On a larger face the number of strokes drops, so the work goes faster, and a longer grip lets you hold the file more firmly and guide it straighter. For small parts and cramped places the shorter models in the same range are more suitable.

How to work with it

• Work with a drawing movement in one direction and without pressure.
• Bring it in only at the end, after abrasive paper, not instead of it.
• Rinse a clogged face with water and let it dry.
• Glass is brittle; do not drop the file and do not bend it in your hand.

Who it is for

The file will be appreciated by those who finish larger faces before a gloss coat, and by builders of cars, motorcycles and models with clear parts. On matte finishes its effect is lost under the paint.

It pays to keep a glass file in a sleeve or at least wrapped in a cloth. Unprotected in a drawer it gets scuffed against the other tools and its fine working texture is damaged exactly where it matters most. Do not breathe in the sanding dust from plastic and resin; work with extraction or at least with a respirator.