Roughening; Fine Cleaning - HBM EP 250 Instructions D'emploi

EP 250
NOTE
Never use solvent that is technically pure; chemical purity is absolutely
essential. Never use solvent directly from the original container, it is better to
first pour solvent into a small, clean dish, from where you can soak up the
amount of solvent you require with the cleaning pad. On no account should
any remaining liquid be poured back into the original container, as this would
contaminate all its contents.

3.5 Roughening

A slightly rough surface is the ideal anchorage for the adhesive. This type of
surface is obtained by sandblasting, etching or by grinding with medium−
coarse emery cloth.
80−100 grain corundum, which must be completely clean and should only be
used once, is suitable for sandblasting. 220-300 grain emery cloth is recom-
mended.
The steps described below should be taken immediately after roughening, to
prevent the formation of new oxide films.
The optimum surface roughness is between 2 µm and 4 µm.

3.6 Fine cleaning

Dirt particles and dust must be carefully removed. With clean tweezers, dip a
cleaning pad into one of the solvents mentioned above and use this to clean
the measuring point. Only ever make a single stroke with each cleaning pad.
Continue cleaning until there is no discoloration (contamination) of the
cleaning pad. Make sure that all the solvent has evaporated, before taking
any of the steps described below.
Under no circumstances must you use your breath to blow away any fluff that
remains or touch the measuring point with your fingers.
A1659-1.0 en/de/fr
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HBM