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View Full Version : Old Lighters & Flint Corrosion ????



JoeLee
01-30-2015, 09:23 AM
A friend of mine brought me a small collection of old lighters he found, he collects these things. Some are pretty interesting and have some interesting logo's on them from various companies such as auto parts stores of the past to local insurance companies. Back then these were sometimes given to customers much in the way a business card would be handed out today.
Any way.......... the issue here is most all of these are old and have been sitting in someones drawer for years, the flints have set up in the tubes in all of these. He wants me to try and remove the stuck flints so he can make all of these operational with out altering the originality.
I've managed to remove the stuck flints in a few of these so far, these were the ones where the flints were almost worn down to nothing more than a thin disc and they were easy to poke out with a dental pick. Some of the others where the flints were full size, about 1/4" long wouldn't budge. I had to carefully dismantle each lighter and try to tap the flint out, they wouldn't budge and fearing that I would damage the small thin wall brass tube I opted to chuck it up in the lathe and drill it out. Once I went through it with the drill the remains just crumbled and fell out.
So................ my question here is......... what it the reason for the flints setting up in these tubes???? is it a galvanic type reaction between the brass and the flint being dissimilar metals???? or do these flints like swell with humidity over prolonged storage???
They are pretty soft material and most likely a powder pressesd into the small cylindrical shape. I'm not sure if it's a corrosive action as there is no sign of pitting to any of the brass tubes. Any ideas ???????

drmico60
01-30-2015, 10:48 AM
Lighter flints are made from mischmetal. This is an alloy of iron with a mixture of rare earth metals. It is a very reactive alloy which is why small hot chips from the flint ignite spntaneously in air to give sparks. It corrodes rapidly in warm moist conditions. In normal use the the flint is used before much corrosion occurs but if the lighter is left around for a long time the flint will corrode significantly. The corrosion products are more voluminous than the parent metal so the flint tends to jam in the flint tube. The flint could be drilled out as you have discovered. It could also be dissolved out with a little acid (hydrochloric acid aka spirit of salt) but this may damage other parts of the lighter.
Mike

JoeLee
01-30-2015, 10:57 AM
Thanks Mike........... that answers my question.

JL.................