Hypos for Felt Marking Pens The so-called "Magic-Markers", which are felt-tipped pens with a metal ink reservoir filled with fibers which hold the waterproof ink supply, are a boon to chemists for placing temporary identification markings on laboratory glassware. These pens have two main faults. One is that the ink supply runs out long before the felt tip is worn out. The other fault is that users often forget to replace the cap, thus allowing the ink solvent to evaporate rendering the marker useless. Pens of this type now east about one dollar ($1).We have found that they can he rejuvenated very simply. If the solvent has evaporated, toluene or aylenel (3-5 ml) can be injected hy inserting a #19 hypodermicneedle between the felt tip and the metal crimp which holds the tip. The pen issoon ready touse again. The cost of the small amount of solvent is less than two cents. Ink can be purchased far these pens a t a cost of $2.70 for 118 ml. Thus if the marker needs to be reinked, 5 ml of the ink can be introduced into the reservoir by the same hypodermic technique as described above a t a cost of eleven (11) cents.
' Do not use benzene as a solvent. It has been designated as carcinogenic University of Guelph Guelph, Ontario, Canada NIG 2W1
672 I Journal of Chemical Education
William Hamilton Brawn
