Do you pre-burn automotive halogen bulbs?

[Hamilton Felix]

Much of my experience is a good many years in the past. But spending as much as I have on fine Cibie lamps over the years, I learned to pre-burn my new bulbs. I like to have an automotive battery on a charger, in basement or garage, so it will maintain at least 13.5 volts. Then I clip nice heavy leads to the bulb and let it burn -- high beam on the H4 bulbs -- until it has been at full operating temperature for a while. In the past, there has often been a little bit of detectable smoke. I do NOT want any of this smoke deposited on the reflectors of my expensive lamps.

In 2010, would you say this precaution is still a good idea?

 

[Alaric Darconville]

...I learned to pre-burn my new bulbs. I like to have an automotive battery on a charger, in basement or garage, so it will maintain at least 13.5 volts. Then I clip nice heavy leads to the bulb and let it burn -- high beam on the H4 bulbs -- until it has been at full operating temperature for a while. In the past, there has often been a little bit of detectable smoke. I do NOT want any of this smoke deposited on the reflectors of my expensive lamps.

I'd say it's a better idea just to clean the entire bulb assembly with mineral spirits or alcohol to remove any foreign material. If the smoking is occuring from the envelope itself, and not the plug portion of the bulb, then you're lucky the bulb doesn't crack or shatter from where the evaporation is taking place. Similarly to how you should never touch the envelope of a halogen lamp with bare fingers without cleaning it afterwards, pre-cleaning can save you hassle later on.

 

[-Virgil-]

I'd say it's a better idea just to clean the entire bulb assembly with mineral spirits or alcohol

+1 on cleaning instead of "pre burning".
+1 on alcohol.
-100 on mineral spirits!!! Use alcohol.

If the smoking is occuring from the envelope itself, and not the plug portion of the bulb, then you're lucky the bulb doesn't crack or shatter from where the evaporation is taking place. Similarly to how you should never touch the envelope of a halogen lamp with bare fingers without cleaning it afterwards

Old info. Most car headlight bulbs are now made out of hard glass instead of quartz. Quartz de-vitrifies when oiled and heated; that's where the "never touch!" warning came from. Glass does not. The only risk with oil (fingerprint or otherwise) on a glass bulb envelope is smoke with resultant optic fogging. Clean with alcohol and you're all set.

 

[Hamilton Felix]

Good point. I have always been careful of touching bulbs, and knew to clean with alcohol if I'd accidentally touched it.

I think the small amount of smoke I'd sometimes see would often come from the base. Imagine lighting, for example, a 100 watt H3 or H1, then blocking your direct view of the intensely bright bulb and looking over whatever you used to block direct view. You'd see a tiny thread of smoke for a short time, as the bulb reached full temperature for the first time. And afterward, you'd see some discoloration on the base that had not been there before.

I don't think much smoke ever came from the surface of the bulb. If the bulb was oily, it would blacken quickly and fail very soon thereafter.

I suppose there are great variations in manufacturing quality control. I think my concern was really the impurities that came along with the base of the bulb. If it's going to smoke when it gets hot for the first time, I don't want that to degrade my reflector.

But I will continue to be very careful about keeping the bulb clean, and cleaning before it ever heats up, if I think it has been touched.

 

[Alaric Darconville]

+1 on cleaning instead of "pre burning".
+1 on alcohol.
-100 on mineral spirits!!! Use alcohol.

Darn, I'm -98 now.

I've seen mineral spirits used on things like circuit boards for .MP3 players and stuff-- guess I figured it wouldn't hurt a simple thing as a light bulb. I guess it leaves more residue than I thought.

(I'm still ultra-paranoid about touching the envelope of any miniature bulb, whether a halogen or not.)

 

[-Virgil-]

I think the small amount of smoke I'd sometimes see would often come from the base.

Probably manufacturing residue. If you're paranoid about it you could swish the bulb in a jar of denatured alcohol.

 

[MichaelW]

What is the best concentration of alcohol?
I have to look extra hard for 99%. 91% is somewhat well stocked, and 70% is everywhere.

 

[-Virgil-]

That bathroom alcohol (isopropyl) isn't as good as denatured alcohol from the paint department of a hardware store. It's called "methyl hydrate" in Canada, "Methylated Spirits" in England, and probably other names elsewhere.

 

[tay]

I was taught that the best way to clean optics was with a lint free cloth, wiping it with acetone first, then with alcohol second.

I've been using a bottle of 94% isopropyl alcohol at home for cleaning lenses and bulbs, and it has been working well. Just don't try to clean chrome with it!

 

[Alaric Darconville]

I was taught that the best way to clean optics was with a lint free cloth, wiping it with acetone first, then with alcohol second.

I've been using a bottle of 94% isopropyl alcohol at home for cleaning lenses and bulbs, and it has been working well. Just don't try to clean chrome with it!

Lint-free cloth that has also never been exposed to fabric softener or dryer sheets, to minimize the possibility that they leave a residue of their own.

I'd be afraid that acetone may deform the base of some bulbs (if they contain certain plastics or nylons). Granted, it would probably be a small deformation or just discoloration, but it potentially could affect the fit in the socket.

Be sure to keep those high concentrations of alcohol tightly sealed; they'll absorb water out of the air pretty rapidly.

 

[Kuryakin]

It used to be, when the 9004s first came out, reflector fogging was a huge problem. Then there was a spec about this, and the sealant manufacturers had to come up with a zero emission flavor of the stuff in the base.
I suspect once this problem was licked for the plastic based bulbs, the spec became pretty much across the board.
Yes, I've had to clean out my E code Cibies for the above problem, but I've not noticed it so much at all my cars lately, even on the daily drivers. I suspect it's not the problem it used to be.

Much of my experience is a good many years in the past. But spending as much as I have on fine Cibie lamps over the years, I learned to pre-burn my new bulbs. I like to have an automotive battery on a charger, in basement or garage, so it will maintain at least 13.5 volts. Then I clip nice heavy leads to the bulb and let it burn -- high beam on the H4 bulbs -- until it has been at full operating temperature for a while. In the past, there has often been a little bit of detectable smoke. I do NOT want any of this smoke deposited on the reflectors of my expensive lamps.

In 2010, would you say this precaution is still a good idea?

 

[Hamilton Felix]

I have a hunch you're right. I have to charge the riding mower battery anyway, so I think I'll put it on a charger and set up some clip leads to pre-burn my latest new bulbs. But I doubt I'll detect much coming off of them. With those old rally H1, H2 and H4 bulbs I used to pre-burn, it probably was something on the metal base parts. A dip in acetone or alcohol might well have removed it.