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Dipping bulbs - Mysterious lost art or rightfully forgotten? (3 replies and 3 comments)

HarryBuck
2 weeks ago
HarryBuck 2 weeks ago

Hello esteemed forum members - forgive the dramatic title, I’m struggling to find info on this.

It’s interested me before, but come to rise for a job I’m planning; essentially the location is a textile factory and we’re allowed very limited access as it will be running throughout production. We need to get in and change the character (mostly colour) of the seamstresses’ desk lamps with minimal intrusion. Controllable LED bulbs not workable for various reasons and they will be seen on camera.

Ideally I’d love to pre-dip a bunch of tungsten bulbs in a few strengths of CTS. Anyone got experience in this? Lots of variables to go wrong here.

Would also be interested in experiences with home-brew crown silvers.

Cheers! H

Mike
2 weeks ago
Mike 2 weeks ago

You can change the colour of bulbs easily by dipping them in a mixture of food dye and diluted varnish. Add white spirit to varnish to bring it down to a thin diluted state and add food dye. The consistency of the varnish must be thin enough for it to drip constantly from a brush. Every time you dip the bulb you are adding another layer of vanish and colouring so the more dips the stronger the colour. Naturally only dip the glass portion of the bulb not the electrode. I got this tip from my father many years ago who was a lighting man and apparently was common practice in British studio’s to save money. Also many photographic studios did the same. There is a snag and that is that the varnish on the bulb has relatively short life as the varnish does eventually crack and peel off. Depends on the wattage of the bulb and it’s heat output but many of my bulbs have lasted years with the coloured varnish intact, it’s really how you use them and how long they stay on is the secret. 

Food dye comes in every colour nowadays so you have a large choice of colour tones and densities. Btw. You can always strip the old varnish off by dipping the glass portion of the bulb in paint stripper, then using again. Let us know how you get on.

HarryBuck
2 weeks ago

Amazing! Thanks for the hot tip (no pun intended) - any advice on things to avoid in either of those substances?

Mike
2 weeks ago

Varnish even if diluted is flammable so keep and eye on that, just make sure you have a fire extinguisher handy but from my experience they are quite safe, none of my bulbs ever caught fire, the varnish is very thin anyway. Have you tried gels, I know they are expensive especially if you need a large number of colours but they do last a long time and are easy to store, they are available in sheets and rolls but will curl up if too near the filament. Live Theatre’s throw out all types of gels on a regular basis, so contact your local Theatre to see if they have any for disposal.

Btw, car accessory shops sell cans of heat proof chrome spray paint so have a think about that too. Don’t forget the kitchen foil method wrapping foil behind the bulb glass to aid reflection.

dmullenasc
2 weeks ago
dmullenasc 2 weeks ago

If you just want to warm them up, wouldn't it be easier to put a higher wattage bulb in and then dim it? Or shoot at a higher color temperature setting?

HarryBuck
2 weeks ago

Thanks for taking the time to reply Dave, I was a big fan of the balance you struck lighting The Love Witch.

The bulbs need yellow adding more than orange, as we’re already playing tricks with the camera colour to battle some ‘characterful’ house lights.

The Byre
2 weeks ago
The Byre 2 weeks ago

Everything depends on time and number - how many lights have to be dimmed and how much time you are allowed to do the dimming.  Swapping out the bulbs for pre-painted ones is a great idea.  Other methods -

Method 1 - old fashioned dimmer packs.  eBay is full of old dimmer packs, either small disco things or whole theatre systems are being flogged off for almost nothing!

Method 2 - wire two bulbs in series so that each gets half voltage.  You need to either know what you are doing or have someone with you who has basic training as an electrician and can pre-wire an extension lead to achieve this.  But the dimming effect is quite profound and may be too much.

Methos 3 - as Mike suggests, gels.  If the bulbs are not to be seen, then this gives you a very accurate adjustment of colour.  You can get large rolls of gel on eBay quite cheaply.

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