Film-Tech Forum ARCHIVE: Streaks on the port glass

This is topic Streaks on the port glass in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=010736

Posted by Stephen LaPadula (Member # 3050) on 12-04-2010, 05:51 PM:

Hello everyone. Most of you will probably not recognize my name, but I registered years ago, and after some time of inactivity could not for the life of me remember my password, or even what email address I registered with. Regardless I have learned an immense amount from so many on this site. Thank you all for that.

Now, for the topic at hand, managers recently assumed operation of the booth at my theatre, and all of the upkeep that comes with it. One thing that has baffled me for months (and annoyed me to the point where I dug up my username and password) is the condition of our port glass. Normal dust comes off easily, but almost all of them seem to be stained by the drying of whatever substance was used to clean them (lens cleaner?)

We have tried soooo many approaches to trying to rectify the situation and get the port glass back to being streak free--just plain damp paper towel, then drying it, lens cleaner, glass cleaner, dry cloth--nothing seems to work.

I was wondering if there are any products that have proved successful for any of you, certain chemicals, or certain types of towels etc. It does not seem to affect presentation, but come to think of it I actually really wouldn't know.

Thanks in advance for any and all help.

Posted by Ron Lacheur (Member # 1126) on 12-04-2010, 07:50 PM:

We have found that Windex with a Squeegee works wonders.

Posted by Brad Miller (Member # 2) on 12-04-2010, 07:54 PM:

Clean the auditorium side of the glass with a horizontal motion and the booth side of the glass with a vertical motion. This way when you see streaks, you know which side of the glass it is on.

I have had great results by putting the solution (I use lens cleaner) onto the paper towel/McDonald's napkin and wiping with light to medium pressure on the glass. Then as fast as possible I follow up with a dry paper towel/McDonald's napkin with strong pressure on the glass. Always worked wonders for me, and yes McDonald's napkins really do a nice job.

Posted by Monte L Fullmer (Member # 2797) on 12-04-2010, 09:32 PM:

What's the trick in cleaning coated port glass windows? Ours are coated on both sides.

I have to dry wipe the glass with a high density type of cloth to rid of dust..

Posted by David Favel (Member # 1125) on 12-04-2010, 09:42 PM:

On noncoated glass, 2/3 distilled white vinegar and warm water.
The first few times you may have to add a few drops of dishwashing liquid just to breakdown the previous chemicals.

Posted by Mike Blakesley (Member # 26) on 12-04-2010, 10:09 PM:

The trick to avoiding streaks is, you have to get the glass DRY. If you let chemicals dry on the surface, streaks will result. If you use a cloth (not a squeegee), use a microfiber wipe of some sort, or at the very least, "good" paper towels.

Brad's suggestion of McDonald's napkins -- I remember that being suggested years ago, but we have no McD's here in town so I've never had the chance to try it.

We use Carquest Glass Cleaner or Windex, but I think just about any good glass cleaner will work fine.

Posted by Chris Slycord (Member # 4239) on 12-04-2010, 11:37 PM:

^^^
Windex is no good for port windows made of optical glass rather than normal "glass."

Posted by Robert E. Allen (Member # 1351) on 12-05-2010, 08:00 PM:

What has always given me a streak-free port is alcohol in a spray bottle and a lint-free rag.

Posted by Ron Lacheur (Member # 1126) on 12-06-2010, 01:52 AM:

quote: Chris Slycord
Windex is no good for port windows made of optical glass rather than normal "glass."

How so? Will Windex damage it?

Posted by Monte L Fullmer (Member # 2797) on 12-06-2010, 02:37 PM:

quote: Chris Slycord
Windex is no good

Windex is a soap based cleaner with ammonia that cold raise havoc with the optical coating. Plus, it leave a soapy film behind when it dries.

(on a side topic, I love to see booths with 409 to clean platter decks. They don't know how much soap is being left behind on the decks when that stuff dries. I wash the decks with plain hot water and a rag and I can get a bucket of soapy water just from cleaning decks that have been previously cleaned with 409...want that soapy junk on your prints?)

Lens cleaner is alcohol based and I've done the alcohol spray bottle trick numerous times on standard port glass.

Posted by Jonathan Smith (Member # 5609) on 12-06-2010, 02:47 PM:

Just curious: Do you work at an AMC?

quote: Mike Blakesley
Brad's suggestion of McDonald's napkins -- I remember that being suggested years ago, but we have no McD's here in town so I've never had the chance to try it.

Man, I can send you a whole box if you'd like. . . At least pre-dollar menu days, they would always stuff a handful in the bag.

What about the frier oil though? I take it that would not be a good addition to the port glass. . .

Posted by Stephen LaPadula (Member # 3050) on 12-10-2010, 04:11 PM:

Thanks everyone for your replies. According to my booth tech The 2D ports are Optical glass and the 3D ports are real expensive Abrissa glass. We have about half of each. I have never heard of Abrasia, but if it rings a bell to anyone please let me know what you use for those.

I will try some of your methods and let you know my findings shortly. To the naked eye the glass look clean, it is just when the light passes through the glass, the streaks are clearly visible.

Posted by Gordon McLeod (Member # 33) on 12-10-2010, 05:34 PM:

http://abrisa.com/

Posted by Mark Ogden (Member # 43) on 12-10-2010, 07:58 PM:

I made this point awhile back, and it bears repeating again: the vast majority of streaks on port glass (or windshield glass, or windows) comes not from the cleaner, but from the rag or towel that is being used to wipe with. Most paper towels are horrible for glass cleaning because they are full of softening chemicals and rewetting agents to make them more absorbent, and when the lens cleaner or Windex or whatever hits the towel it causes all this crap to emulsify onto the glass leaving streaks. The same for towels: any towel or rag that hasn't been throughly rinsed of detergent (or has been rinsed instead in water containing fabric softener) will do the same thing for the same reason. That's why many auto detailing pros use wadded up newsprint for glass cleaning: it's just plain old paper.

Back in the day, I kept a roll of bathroom paper towel dispenser towels (the roll kind, not the C-fold kind) in the booth with me just for port glass cleaning, and it worked like a charm, probably for the same reason Mickey D's napkins do: they don't have all of this chemical stuff in them.

Posted by Joe Elliott (Member # 4006) on 12-11-2010, 09:26 AM:

Stephan, if I am reading your post right you are not complaining about it being hard to remove streaks that you put on the glass, but rather that there are streak stains stuck on the glass that you can't remove.

There are two possibilities if that is the case.
1. The coating on the glass has been damaged by a cleaner, or
2. The cleaner they used dissolved something (like the paint around the frame), and it is stuck on the window.

We would use alcohol on our windows, and it would dissolve the paint on the frame and leave streaks that you could not remove normally. Test a small corner with rubbing alcohol and see if it removes it, and doesn't damage the coating. We had glare reduction coated glass, and alcohol did not bother it, but I can't speak for all types and brands of coatings, so better safe than sorry. Be careful to not get any of the paint on the frame to even touch your towel.