Hi, novice is replacing headlamp bulb on 94 Corolla. Neighbour says that with new bulbs, he is alway carefull not to touch the glass, and even new from the factory he wipes them with methylated spirit in case they have been been touched.
Would the assembled great minds agree that this methylated wipe should be done?
If you have handled a halogen bulb with your fingers then yes, your prints burn a weakness into the glass. Ordinary bulbs, no.
PDH
If the glass has been touched, yes. Grease off your skin gets on the bulb and gets burned onto the glass, darkening it and making it overheat.
No, it's pointless. I've not wiped a bulb in the thick end of two=20 decades despite spending some time working as a mechanic. Just don't=20 touch the glass.
--=20 Conor
I'm really a nice guy. If I had friends, they would tell you.
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don't touch the glass at all out of the box.
hold with tissue or soft cloth when installing them
if you haven't touched it there is no point in the extra wipe, if you have, then wipe. The less that gets on the bulb (including meths), the better.
if they r new, and from a sealed box, no need to wipe, but if they have been loose or what ever, and you can see marks on them, give them a polish
Neil - Usenet wrote: I always wipe them but i know someone who never does and has yet to have one go wrong in 20 years lol.
I wonder if it's an urban myth? We use halogen lamps in filming - some of which use bulbs as small as car ones - and hairy arsed sparks ain't going to be that careful. The replacement comes out of all packaging in the van and is plonked in the lamp. And gawd knows what's on their fingers after reading Loaded for most of the day.
YOu normally hold them by the little paper sleeve they come in when you're doing that. If you don't & you've got greasy fingers you can see som really obvious fingerprints etched into the quartz.
Indeed - but that's why I mentioned 'all packaging'. It doesn't make it to the set.
Being in the manufacturers fitting info I have always assumed it was there for a reason, but how much difference it makes quantitively would be interesting to see.
It doesn't kill them straight away, it just reduces the life significantly.
How long do your bulbs last? Notice how they always have plenty of spares and they need changing fairly often?
If they were more careful there would be less work for them to do... ergo...
It doesn't quite work like that though, less work means more time drinking tea.
I suppose its similar in effect to buying cheap or expensive bulbs. I personally buy cheap bulbs but keep them clean. Never had a failure of any bulb ive fitted. But then if you buy expensive and mis-handle them you might have the same lifespan as a cheap well handled one. Both well handled, the expensive one would out-last the cheap. Too many contributing factors in the real world, though im sure it makes sense to keep them cleaned if possible.
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