This is topic WD-40 and optical sound in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Rick Long (Member # 213) on 09-14-2003, 11:26 PM:
 
Many film-tech members have scorned the use of the popular lubricant WD-40 for use in the projection room, and for good cause. An common occurance is a sticky Simplex G-1985 sound roller assembly, lubricated with WD-40 frees up, but only for a short while.. A week or so later, it is stickier than ever.

However, as I recently found, it can be even more harmful to the proper reproduction of motion picture sound.

I had a call to one of our theatres, 70 miles outside Toronto regarding a "muffled sound" in one of their auditoriums. This booth was equiped with Cinemeccanica Vic 5, and Dolby CP-65 (optical playback only).

Upon arriving at the theatre, I ran the Dolby 251 test reel. I carry this reel on a Strong platter take-up ring, as it provides the quickest method of use.

It had not run for more than a minute when I headed back to the booth.

The theatre had a Bay Area red-led conversion kit installed last spring. It seemed that something was out of alignment with this. (I was biased in my thinking by similar problem a few weeks ago when a unit (that I had NOT installed, btw) was found to be insufficiently tightened such that someone accidentally dropping their had on the "box" caused it to go out of alignment.

Such was not the case here, the box was quite tight in its mount.

I checked buzz-track and tone and then threaded C.N. 69P pink noise test film. (Abacus and Hitachi 20-Mz scope connected to the 240 card). I did notice at this point that the two "lay-on" rollers which sit on top of the sound drum were not turning, and were rather grungy-looking. I removed these and using Brasso and 3-in-one oil, lubricated the rollers and shafts. It was about this time that I noticed the can of WD-40 sitting on the electrical trough in front the projector (half empty, spray nozzle attached). Hmmmmm.

Upon running the 69P test film, I noticed that, as I suspected, the highs were much lower than the low-freqency component.

The results, however, are not what I would have assumed with an out-of-focus lens.

An out-of-focus lens usually causes the higher frequencies to drop rather rapidly. This one had a peculiar 45-degree angle drop from about 500 Hz to about 16 Hz.

I removed the plug-in card from the cell box and stared at it. Smelled it too (nothing burnt). I realized that there weren't much me and my American Beauty 100-watt soldering iron could do for this anyways. I began to try and estimate the time-cost of negotiating traffic through the greater Toronto area, during rush-hour,to our shop to get another "box" and back to this theatre before show-time. I decided against it.

I un-plugged it and pulled the box. The only clue I had was that the lens had a peculiar "color" to it, not so much like a treated lens, but one that had an "oily" hue to it. Perhaps, while trying to spray WD-40 to free the lay-on rollers, someone had lubricated the sound lens too. I thoroughly cleaned it with lens cleaner and cue-tips.

Long story short, I cleaned the lens, re-installed it and performed a complete A-chain on it, and it came up beautifully.
 

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Posted by Manny Knowles (Member # 1171) on 09-15-2003, 08:27 AM:
 
This is one of the main reasons why Dolby instructs us to clean all the optics before conducting A-Chains. You could've isolated the trouble inside of a couple of minutes.

As for the WD40: It really bothers me when people leave things broken and just find a way to "work around it." They ought to get that sound head properly fixed.

There's a good chance that the movie (and your test film) got some WD40 transferred onto it.
 

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Posted by Edward Jurich (Member # 1787) on 09-15-2003, 11:20 AM:
 
WD-40 is good for cleaning stubborn dirt off like old grease or oil and hardened dirt. If you spray it on a cloth then wipe the surface to clean you avoid getting it on where it shouldn't be.
 

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Posted by Paul G. Thompson (Member # 655) on 09-15-2003, 01:37 PM:
 
Edward, it is probably the stoddard solvent in WD-40 that helps in the removal of stubborn oil and grease. The petroleum product in it just acts like a magnet to attract more dust and grease.

It is just as good to get that WD-40 out of the booth before somebody else picks it up and starts spraying the equipment. I maintain that today's projection booth has no place for a can of WD-40.

For removing stubborn grease and oil, I use just regular old-fashioned brake cleaner.

[ 09-15-2003, 07:28 PM: Message edited by: Paul G. Thompson ]
 

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Posted by John Pytlak (Member # 331) on 09-15-2003, 01:50 PM:
 
Citrus-based cleaners like D-Limonene are very useful in metal and electronics degreasing operations:

http://www.epa.gov/ozone/snap/solvents/sol_met.pdf

http://www.epa.gov/ozone/snap/solvents/sol_elec.pdf

http://www.protonique.com/unepstoc/report/STOC1998ch3.pdf

http://zim-intl.com/chemicals/dlimonene.htm

http://www.interstateproducts.com/natural.htm
 

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Posted by Charles Everett (Member # 889) on 09-15-2003, 05:32 PM:
 
What wondrous timing! American Splendor has a scene where a can of WD-40 is lying around the house.

The moment I saw that blue-and-yellow can I immediately thought, If there's a can of WD-40 in this booth it's gonna get chucked out in the trash!
 

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Posted by Robert D. LaValley (Member # 1867) on 09-16-2003, 12:37 AM:
 
I use denatured alcohol to clean alot of the film path and various things in the booth. it works really well and doesn't leave a residue. Works well on glass and especially on platters and rollers.
 

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Posted by John Pytlak (Member # 331) on 09-16-2003, 09:50 AM:
 
Robert D. LaValley wrote:

quote:

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I use denatured alcohol

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