"Indelible Ink" on T-3 Headlight bulbs

[Joe Maulsby]

Word or caution, after 40+ years the ink on the back of the bulbs is VERY fragile. I learned this the hard way last night. I used a soft dry cloth to wipe off the dust off of the first bulb and the orange ink went away with the dust! Thought I would be smarter on the 4th bulb and use a mild window cleaner and a soft cloth, the ink started to smear and I stopped wiping. One bulb did not have any ink and the other bulb ink was not legible, except for a 9 in the year code position (1959).

There are two lines of numbers/letters near the plug prongs, stamped into the glass. Anyone know what those number/letter combos represent.

[Mark F.]

Re: "Indelible Ink" on T-3 Headlight bulbs

I used windex on a 1972 dated T-3 bulb this weekend without a problem. It could be that the older ones had a different ink, or the increase in years adds to the problem. Anyway, no matter their age, I agree, a word of caution is necessary when cleaning them.

Mark Franken