Film-Tech Forum ARCHIVE: Painting A Shutter Blade

my profile | my password | search | faq & rules | forum home

»	Film-Tech Forum ARCHIVE » Operations » Film Handlers' Forum » Painting A Shutter Blade

Author

Topic: Painting A Shutter Blade

Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

posted 05-09-2002 01:45 AM

I've got a shutter blade here that needs a paint job.

Is there a special paint for this, or could I go ahead and use a matte black spray paint?

------------------
And, hey! Let's be careful out there.

~Manny.

| IP: Logged

Pete Naples
Phenomenal Film Handler

Posts: 1565
From: Dunfermline, Scotland
Registered: Feb 2001

posted 05-09-2002 01:57 AM

It's going to have to be some form of high temperature paint, as sold for motor cycle exhausts, etc.

| IP: Logged

Dave Williams
Wet nipple scene

Posts: 1836
From: Salt Lake City, UT, USA
Registered: Jan 2000

posted 05-09-2002 03:12 AM

What kind of projector are we talking about here? I have worked with several makes and models, and all I have done is taken out the blades and give them a really good cleaning. I personally have never thought of painting that, but hey, I haven't seen everything yet. My thought echoes the heat thought here, that the heat from the xenon will just melt anything unless you use a high temp paint. Same stuff they use on engine blocks, just try an auto parts store.

Dave

| IP: Logged

Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000

posted 05-09-2002 03:37 AM

Personally, I don't think it is necessary to paint the shutter blade. Most are black, this is true. But some are unpainted, like the Ballentyne Pro-35. I think the Christie shutter is un-painted also.

As a passing thought that just occured to me, maybe it is better off not being painted. Black paint absorbes heat - just what you don't want, especially if it is a flimsy shutter to begin with. Just my thought.

| IP: Logged

John Anastasio
Master Film Handler

Posts: 325
From: Trenton, NJ, USA
Registered: Sep 2000

posted 05-09-2002 06:27 AM

Motiograph shutters weren't painted either. High temp black paint used to be called "stove paint", as I remember from my wood-burning days.

| IP: Logged

Jon Bartow
Master Film Handler

Posts: 287
From: Massachusetts
Registered: Nov 1999

posted 05-09-2002 07:17 AM

I received from Strong a couple of days ago two new century 100deg shutter blade assemblies that are both painted with a baked enamel black crinkle finish paint. They even balanced the blades after painting (i.e. there are a couple of points where they drilled off the paint) These assemblies weigh nearly twice what the other ones do.
I'm installing these blades today in two projectors running Century MSA's and Christie SLC consols with 4500w bulbs. Without heat filters for the lamp. only a standard water circulator for the gate.
The old blades are just the standard 100deg blades that are basically spray painted black. Those blades are warped from the excess heat. One of them has a spot where I could probably poke my finger through the metal if I wanted to. I fully expect them to break when I remove them today.
Jonathan

| IP: Logged

John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 05-09-2002 07:19 AM

A black finish will absorb more radiant energy, causing the shutter to get hotter. But a lighter reflective surface will reflect the light back to the lamp, and the extra light may "bounce around" within the shutter housing, such that some goes out onto the screen when the shutter is supposed to be closed.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

| IP: Logged

Darren Briggs
Master Film Handler

Posts: 371
From: York, UK
Registered: Dec 2001

posted 05-09-2002 08:11 AM

Cinemeccanica shutters are just plain metal.
What would painting it achieve?
The light is either cut off or open to the film?!?!

Spend your paint money on chocolate's for the girlfirend.
Darren

| IP: Logged

Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

posted 05-09-2002 10:33 AM

This particular one has lost its finish and has silver spots that cause an annoying flashing effect that hurts my eyes whenever I go near the machine during operation.
The projector type is Century...but it's likely a Monee copy.
The shutters for these machines were all originally painted with a black matte finish.

------------------
And, hey! Let's be careful out there.

~Manny.

| IP: Logged

Jerry Chase
Phenomenal Film Handler

Posts: 1068
From: Margate, FL, USA
Registered: Nov 2000

posted 05-09-2002 11:22 AM

Barbeque grill paint works well. JP is right that light bouncing around the shutter box can spill. Try running an open soundhead while the shutter housing is off.

If you look at the angles, you may find that light reflecting off a shutter bounces back to the metal at the back of the shutter housing, where it can then bounce forward again either directly through the gate or to the metal on the front of the housing, back onto the front of the shutter, and out through the gate. I had this problem with some DP-75s when I was first in the business and it was only much later that I figured out what was going on. The light showed up as an unresolvable very dim travel ghost at the very top and bottom of the screen even with proper timing and the shutter blades being the nominal width. In my situation, it was only noticable during the white on black credit roll. If I had had a brain and hadn't been afraid of modifying equipment, I would have spray painted the snout of the lamphouse and the offending areas of the interior.

I suspect that the designers of barrel and counter-rotating shutters may have been aware of problems like this.

| IP: Logged

Will Kutler
Phenomenal Film Handler

Posts: 1506
From: Tucson, AZ, USA
Registered: Feb 2001

posted 05-09-2002 05:58 PM

Christies blades are unpainted. they have a glass beading finish and thus are dull. These blades are also balanced.

Most other blades that I have seen are either aluminum or steel. For aluminum or pot metal parts, prime with zinc-oxide or self etch primer. Zinc chromate primers are no longer available. Every shutter that I have seen (other than Christie) has been painted a flat black. Use Dupli-Color ceramic based high temp engine paint (available in black) This is also oil and gas resistant. Available in spray paint. NAPA Auto Parts is an authorized distributor...or visit Dupli-Color web site...a Sherwin Williams product. I have used this on my small block Ford, and it is pretty good stuff.

| IP: Logged

Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 05-09-2002 06:38 PM

Some new shutter blades are black anodized. This eventually fades form the intense light. On machines like a Century or E-7 these faded blades can kick back dseom light into the booth through the holes in the guard. That can be annoying but either flat black header paint, or stove enamel is fine to use. Just be sure to have it really clean when you paint it.
Mark @ GTS

| IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 05-09-2002 09:12 PM

If you have the light, the Century C1-D-50S (100degree steel) shutter blades are definately a nice touch. They make the image on screen look oh so nice...shutter timing is also never a problem. The current standard Century shutter is the C1-D-48 which is light-weight (warps) and is only 90 degrees (essential to eliminate travel ghost on a Century).

Steve

------------------
"Old projectionists never die, they just changeover!"

| IP: Logged

Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 05-13-2002 11:34 AM

We installed a standard Xetron lamphouse (1600w) on an Eastman 25B 16mm projector and found ghosting that looked like an out of time shutter. Checked the shutter and found it to be in perfect sync. After a lot of head scratching, I finally pinned it down, just as John suggested, to light bouncing around the unpainted, aluminum shutter housing. Since this was a lamphouse designed for 35mm, the light cone, even when properly focused, spills all over the mouth of the porjector's change-over shutter and main shutter aperture. There was enough light bouncing around and being refected off all that shiney aluminum that enough sneaked under the shutter to cause ghosting. I didn't paint the shutter itself, but just the aluminum housing and that did the trick. I used "Stove Black" Crylon paint -- you can pick it up in any hardware store.

| IP: Logged

Dick Prather
Master Film Handler

Posts: 259
From: Portland, OR, USA
Registered: Feb 2002

posted 05-13-2002 11:52 PM

anytime I needed to paint a shutter blade I just used a good quality flat black. I have used several brands and had no problems with any. I painted most flat or conical blades to keep any stray light from reflecting in the booth or outside. I didn't paint Motiograph because they were nicely covered in their little box which helped keep stray light in. I have not had a painted shutter cause any problems when used in a proper manor. If it stops the kind of paint won't make much difference.

| IP: Logged

All times are Central (GMT -6:00)

Printer-friendly view of this topic

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.