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bob carnie
18-Jul-2009, 11:11
Hi Folks

I started a soundproof thread and got lots of great advice.

As in that thread , I am building a new darkroom within my lab, and part of the problem will be that the darkroom will be directly below a huge skylight.
The skylight is 16ft and the darkroom ceiling will be around 8ft.
Blocking the skylight is not an option as it will also light other areas of my operation.
I am looking for black out material for the ceiling basically .
The material must be lightweight and able to cover large areas. Any advice would be appreciated or links to blackout material.

I also know that putting a Darkroom under a huge skylight is not the greatest move in my photo lab experience, but neverless this is what I need to do.

thanks in advance

Bob

vinny
18-Jul-2009, 11:19
Bob, Duvetyne aka "commando cloth" is an expensive but foolproof option. The movie expendables places in Toronto have it. There's also a black paper on large rolls we use for blacking out windows that they may have as well. I can't recall the name of it. Lastly 6 mil visqueen would be the cheapest option from any lumber supply joint.

PenGun
18-Jul-2009, 11:38
The black/white plastic sheeting the growshow guys use is opaque. Cheap and comes in 10' wide.

Greenhouse supply if you can't find the growshow store.

Mark Woods
18-Jul-2009, 12:16
I've used roofing felt for many darkrooms. When I was in college, I used it stapled over the window in the wash porch I used for my darkroom. It worked great. Light tight. And very cheap. You could build a frame for the darkroom and put the felt on it. The visqueen is a good solution, but doesn't breathe. And the duvatine is also good, but I'm not sure you could make it totally light tight. (I've used it many times in my day job as a Cinematographer and have a roll of it.)

MW

Joe Smigiel
18-Jul-2009, 22:01
Roc-Lon curtain blackout material is used in hotels, etc. It is completely opaque but also white or Ivory in color so it reflects light (safelights for example). It is fairly inexpensive and any decent fabric store will carry it.

blackoutcurtains.com is another source for specialized fabrics. The company is based in minneapolis. phone 866.BLACKOUT

Donald Miller
18-Jul-2009, 22:28
In addition to darkening the ceiling of your darkroom, you could construct a reflective box (tent shaped structure and mirror surfaced) suspended beneath the skylight. If this were constructed to a couple of feet greater dimension than the skylight and built with a 45 degree slope to each of the four upward sloping sides with sufficient distance beneath the skylight you would reflect any light from the skylight well beyond the perimeter of your darkroom enclosure. This would save a great deal in construction costs and also solve all of the ventilation problems. I have seen a adaptation of this design used in spot lighting the interior of a manufacturing area.

Gary Beasley
19-Jul-2009, 07:56
If this is a permanent structure the wood framing and sheetrock should be very effective at blocking all light, so this is a temporary darkroom?

Kirk Keyes
19-Jul-2009, 08:36
plywood works pretty good. And you can make it removable too.

bob carnie
19-Jul-2009, 09:42
Hi Gary
The ceiling is the problem, I do have large sheets of black plastic that we have used in the past in ceilings for this purpose, but for this permanent darkroom a monster skylight is above the darkroom space so hanging a ceiling is problematic.
We will build a roof structure above the 8ft drywall , use the plastic, and hopefully use some sort of lightweight blackout material for added protection.
This roof will hopefully a lightweight solid attachment that effectively blocks out light from above.
Air, Exhaust will be supplied from the roof into specific areas of the lab.


If this is a permanent structure the wood framing and sheetrock should be very effective at blocking all light, so this is a temporary darkroom?

Nathan Potter
19-Jul-2009, 10:30
Bob, I've used black PVC pond liner material for window blocking. I think it may be 20 mil thick IIRC. Very durable but would need to be moderately supported by a frame. The 40 mil thick butyl rubber liner material would be good also but is fairly heavy.

Nate Potter, Harrington ME.

Gary Beasley
19-Jul-2009, 13:53
Hi Gary
The ceiling is the problem, I do have large sheets of black plastic that we have used in the past in ceilings for this purpose, but for this permanent darkroom a monster skylight is above the darkroom space so hanging a ceiling is problematic.
We will build a roof structure above the 8ft drywall , use the plastic, and hopefully use some sort of lightweight blackout material for added protection.
This roof will hopefully a lightweight solid attachment that effectively blocks out light from above.
Air, Exhaust will be supplied from the roof into specific areas of the lab.

A properly framed ceiling structure of wood will hold plywood panel and sheetrock (theres a thinner version made for ceilings). If well made, a plywood ceiling/roof can be used as a storage deck for extra gear, look at the way decks are made.

Drew Wiley
19-Jul-2009, 14:10
AV curtain material can often be had in significant yardage cheaply, since it's not in
demand much anymore. But being vinyl, it tends to outgas a lot. True studio flocking
is as black as something gets, but tends to attract dust and spider webs in a manner
which is difficult to clean off. A coulple layers of 6-mil black polyethylene works well, but tears easily and you have to patch over the staple holes or whatever. Better just to suspend a floating ceiling and caulk and paint it. Sounds like you're on
the right track, but again, beware of large surfaces which outgas and might smudge
your lenses and make the room unpleasant.