[SML] How to gauge the age of a Source Four?

Sun May 3 03:13:00 UTC 2020

Mentioning cleaning the reflector, back when I worked on industrial lasers (cutting type, not theatrical), the big expensive primary lens would get a burned on smoke coating.  This was extremely hard to get off so as an experiment I used 1 micron diamond powder in alcohol.  Worked quite well, just wet a fingertip with it and rub gently.  Rinse with distilled water, blow dry and back to work.

⁣---
Jerry Durand, Durand Interstellar, Inc. +1 408 356-3886
www.DurandInterstellar.com & www.DurandInterstellar.ru

On May 2, 2020, 17:28, at 17:28, Dale Farmer via Stagecraft <stagecraft at theatrical.net> wrote:
>Paint flaking off of the lamp cap over time is normal, and the photons 
>don't care about that paint or lack thereof.   I'll speculate here, but
>
>I think ETC switched to a low or no VOC paint process and the different
>
>coatings react differently.
>  Paint adhesion over time is one of those simple sounding things that 
>turn out to be stupendously complicated.  formulation of the paint, 
>surface preparation of the painted surface, primer, application 
>conditions, curing conditions, working life conditions.  I took a dive 
>into that a few years ago, and quickly bounced.   Physics and chemistry
>
>and manufacturing and end users all matter.
>
>   The reflectors, they do take on a yellowish hue on the reflector 
>surface over time.  This presumably changes how it reflects or passes 
>the various wavelengths.  I believe this is aging of the coating, but 
>that really is just a guess on my part.   It does change the light 
>coming out the front, but I never had the means to actually measure it 
>other than using the Mark I eyeball.  It seems a bit darker, but won't 
>try to quantify it more than that.
>  I will say that some fixtures that were in night clubs, before they 
>banned smoking, that the yellowish tinting of the coating was stronger,
>
>but a vigorous cleaning removed a lot of it.
>  I have no doubt that ETC's local dealership would be more than happy 
>to sell you as many replacement reflectors as you care to buy.   Might 
>just be easier to group the older fixtures for specials and the new
>ones 
>for washes.
>
>Dale
>
>On 5/2/2020 2:03 PM, Jon Ares via Stagecraft wrote:
>> I was able to go into my facilities yesterday to start prepping for a
>
>> buncha new fixtures, and found some interesting things, and I'm
>curious 
>> about any other "changes" that have come to the Source Four over the 
>> years...
>> 
>> I have some bodies that are 2015, and others that are 2006.  All use 
>> 575w HPLs, some long-life, none at 750w. All the 2015s all have 
>> cooked-off paint on the lamp housing.  The 2006s still look fine.
>> 
>> The reflectors are clean on both bodies, but the 2015 reflector has a
>
>> definite 'cooler' color to it... the older ones have a warmer tone.
>But 
>> they're clean - no haze.
>> 
>> So have there been changes in paint?  Reflector coatings?
>> 
>>   - Jon
>> 
>> 
>> On Sat, May 2, 2020 at 10:56 AM Dale Farmer via Stagecraft 
>> <stagecraft at theatrical.net <mailto:stagecraft at theatrical.net>> wrote:
>> 
>>     The source 4 middle bodies are, afaik, unchanged from the early
>days.
>>     Single and double yoke bolt versions were the only distinctions,
>I can
>>     recall.
>>        Reflector housings went through a couple of changes early on. 
>Main
>>     one was adding baffles to the air vents facing back to reduce
>light
>>     leaks.
>> 
>>     The lens tube revs only matter when you have a broken one needing
>to be
>>     replaced or your are changing the glass out of an existing lens
>tube.
>>     ETC doesn't keep old revisions in stock, so you have to purchase
>a
>>     matching pair of the newest revision, and the unbroken half of
>the old
>>     lens tube goes into the bin of misfit parts, in hopes that it
>will be
>>     useful for a future broken other half of the same revision lens
>tube.
>> 
>>     trying to mate different revs of the left and right lens tube
>castings
>>     is an exercise in futility.  they designed the mating lips of the
>two
>>     castings so they only fit together properly with the same rev. 
> You
>>     can
>>     force them to go together, but now the lens tube is out of round,
>>     leading to glass falling out when it's bumped, and it won't fit
>into
>>     the
>>     rest of the fixture easily.
>> 
>>     The lamp caps are the old 575 watt or below only, 575/750s, and
>the
>>     dimmer doubler ones.   There are lots of the old 575 caps around
>that
>>     people drilled out to allow 750 lamps to fit, but they need that
>extra
>>     heat sink and light blocking casting to handle the heat long
>term. 
>>     When
>>     you don't have that extra heat sink, the heat messes up the
>dichroic
>>     coating on the reflector, giving it a case of dandruff. (flakes
>falling
>>     off)  At that point you have to replace the reflector, which is a
>bit
>>     spendy.
>> 
>> 
>>     Dale
>> 
>>     ____________________________________________________________
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>> 
>> 
>> 
>> -- 
>> Jon Ares
>> www.arescreative.com <http://www.arescreative.com>
>> 
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>
>
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