Corrosion of Lowel Tota sockets. Is this normal?

[Les Wilson]

I love all my Lowel gear. I picked up two Lowel Tota lights on eBay. After a while they gave me some trouble. I noticed the sockets and bulbs had corrosion. Cleaning helped a little but inevitably they'd stop working and I'd have to clean them again. One is in a Chimera and a little bit of a pain to extract it, get it working, reinsert it, stops working, turn the bulb.... you get the idea.

I do run them on a dimmer (router speed controller type). IS this normal for the Totas? ANyone else have this problem?

P.S. I accidently found replacement parts for only $11 on B&H. After about 30 minutes, they are as good as new.
http://www.bhphotovideo.com/c/product/305897-REG/Lowel_96008_Tota_Inner_Shell_with.html

[Christopher Young]

Yes have had the same problem over the years. Replaced the ends like you have a couple of times now. The amount of current draw and heat generated at those contact points must be pretty high so I'm not surprised that they do fail after a while. In fact I don't run 800 watt lamps in them any more. I'm using 500 watt 3200K ones from my local DIY store. Way, way cheaper and I find for most modern cameras 500w is more than sufficient.

Chris Young
CYV Productions
Sydney

[Warren Kawamoto]

That's not corrosion. What happens is that the contact between your bulb and the socket is poor, so it begins to arc when you turn on the power, which pits and erodes the socket connector. The key here is to keep the socket perfectly clean for maximum metal to metal contact. Once the crud begins to form, more arcing will occur because of poor contact. Less metal to metal contact means more arcing. It's a vicious cycle that will quickly spiral downhill. I spin the bulbs on its long axis (without touching the bulb with my fingers of course) a couple times every so often to make sure there is maximum metal to metal contact.

[Les Wilson]

That sounds about right, I can hear it arcing. In terms of extended life, are new lamps in order now that the sockets are clean?

[Warren Kawamoto]

You can still salvage the lamps by polishing the end contacts with very fine sandpaper, make sure all of the pits and molten metal fragments are smooth and shiny.

[Christopher Young]

Spot on Warren.

All the same I keep them religiously clean and sanded down with fine emery paper, both the globes and the sockets but sure enough they will start to arc, crackle and fizz away eventually. There is no 'heat sink' capability in the very light construction of these lamps so they get very hot. Way hotter than Red Heads. My Red Heads and 2k lamps with their much better heat dissipation with the much larger ceramic holders they are built with have never given me as many problems as theses tiny little Tota lights.

Their size for travelling is their convenience and in exchange for that I'm prepared for the durability trade off. Still hunting for some small high CRI (90~95 +) LED fixtures to replace them with so until then I will continue to use them.

Chris Young
CYV Productions
Sydney

[Warren Kawamoto]

Off topic, but Chris, I found these high cri leds and ordered 2 1 meter strips (1 blue diode, 1 violet diode) to evaluate. I want to build my own panels!
High CRI LED Lighting Supplier | Beijing Yuji International

[Christopher Young]

Looks and sounds very interesting indeed Warren. Keep us posted or link to a new thread. I think there will be a few following your experiments.

Chris Young
CYV Productions
Sydney