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Smoke around door edge effect

Discussion in 'General Advice' started by kenact, Nov 1, 2018.

  1. kenact

    kenact Member

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    Brooklyn, NY
    I'm sure someone in this forum has done this before, but I searched through 15 pages of search results, and didn't find a solution.

    I need to have smoke coming around the edges of a working door, to simulate a fire in the next room.

    Off Off Broadway (no budget). I have my own ADJ Fog Storm 1700 with a working DMX Remote. The fogger works, but I need to direct the fog to the cracks in the door, and I need to be able to control it from the booth.

    I tried channeling the fog into a couple of small rubber tubes, like those used for fish tanks. The tubes had to be about 10 feet, but I couldn't get the fog all the way to the end of the tubes.

    HELP! Please.
    RonHebbard likes this.
  2. RonHebbard

    RonHebbard Well-Known Member Premium Member

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    Burlington, Ontario, Canada
    @kenact A few thoughts for you.
    1; Think in terms of getting an airflow established then use the machine to inject fog into your already established air flow so the air will carry the fog along for the ride rather than having to depend upon the fogger to provide all of the propulsion for the entire distance through the small diameter tubes.
    2; Larger diameter tubes will offer better air flow with less restriction.
    3; Consider a funnel with a fan behind it establishing an airflow into your tubes. For example, consider a ten or twelve inch diameter funnel fitted into as large diameter tubing as you can deal with. Make the joint between the funnel and your tubing air tight. Place a ten or twelve inch diameter fan four to six inches away from the mouth of your funnel. Turn the fan on and leave it running. Direct your fogger's exit to expel fog into the gap between the mouth of your funnel and the front of your fan. You'll need to experiment with the duration of fog and the lead time required for it to follow the established air stream through your tubing. Put your grade eleven physics classes to work for you, best wishes and luck.
    4; Purchase appropriate connectors and cable and solder up a suitable extension cable for your fogger's remote. Your remote will likely work up to 100' on 18 or 20 gauge copper cable. You're only extending low voltage control signals NOT the power for the fogger's heater or pump. There's no need to purchase connectors that match those already on your ADJ fogger. Think of it this way: Cut the cable on the remote approximately a foot from the connector. Strip off 3/4" of the outer jacket and note the quantity, gauge and colors of the cable's inner conductors. Purchase two mating pairs of connectors designed for enclosed secure attachment to cables, NOT connectors designed for chassis mounting. Install a female connector on the 1' length that plugs in to your ADJ fogger. Install a male connector on the remainder of your remote control's cable. Check all of your work for good soldering or crimping with no excess bare conductors to possibly short. Plug everything back together and fully test. Assuming everything is good, install two more mating connectors on your 100 feet of extension cable, fully check your work and get on with life.
    EDIT: Elaborating on connector choices. Rugged, durable, latching connectors which grip solidly on your remote control cable's outer jacket are what you're looking for.
    Ideally chose connectors which DO NOT mate with anything else in your building. All too many people operate on the "If the plug fits it MUST be right" theory so consider the following when choosing your connectors:
    Your connectors are only handling low voltage, low current, control signals.
    Connectors to AVOID and why:
    Connectors normally associated with higher voltages and currents such as:
    Household parallel blade, grounded and non grounded.
    Stage pin connectors, grounded and non grounded.
    Twist locks of all sizes and ratings.
    XLR-3; Commonly used for microphone and line level audio (And economy DMX).
    XLR-4; Commonly used for intercom headsets.
    XLR-5; Commonly used for DMX.
    XLR-6; NOTE: XLR-6's are manufactured in two NON INTERMATEABLE configurations.
    XLR-6's in the Switchcraft compatible configuration are often utilized for dual channel Clear Com systems.
    XLR-6's in the NON Switchcraft compatible configurations MAY be a good choice for you.
    XLR-7's MAY be a suitable choice for you unless you're already employing them in your facility.
    Speak-ons and Powecon's of all flavors should be avoided for this application.
    @kenact Is this making sense to you so far??
    Ron Hebbard
    Last edited: Nov 1, 2018
    macsound, Amiers and Van like this.
  3. bobgaggle

    bobgaggle Well-Known Member

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    Shop Foreman
    Philadelphia, PA
    As always, Ron has the most elaborate answers.

    I wonder why you can't just position the fogger behind the door and smoke it. Take some stock flats and build a little vestibule with a ceiling behind the door (I'm assuing this is a exit door through a wall to offstage, not a free standing door in the middle of the stage). The vestibule will keep most of the smoke from drifting upward, and you'll get some through the door gaps...

    edit: If you go this route, obviously please consider breathable air if someone is waiting back there to burst on stage and announce a fire or something like that...
    macsound likes this.
  4. kenact

    kenact Member

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    Brooklyn, NY

    Thanks for all the info. I do follow what you said. I probably should have been a little more clear, but I've been running on 4 hours sleep a day, trying to get this production up.

    The only reason I mentioned controlling things from the booth, was to suggest I couldn't have anything that would have to be moved into, and back out of place.

    I have the DMXT Remote for the Fog Storm, and I'm able to control it via DMX from QLC+. All of that works fine. I have a DMX cable (not a mic cable :) ) running to the remote.

    The problem I was having was figuring how to get the smoke to the seams in the door. The ideas you have for that are excellent, and I thank you.
    macsound and RonHebbard like this.
  5. mbrown3039

    mbrown3039 Active Member

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    vegas, baby..!
    My solution would be to combine the two ideas above: before High End's F100 -- and for those of us that couldn't afford cracked oil foggers -- the way to control your fog was to build a fan box. Basically, it's a metal or wood box with a squirrel fan in it and a flapper door; we'd pump fog into the box and, when ready, turn on the squirrel fan -- that would generate enough air pressure to have all of the fog come out at once (sort of). Of course, the F100 blew that out of the water because it looked almost like CO2 jets.

    In your case, build a giant fan box around and above the doorway with flats and turn the fans on before injecting the smoke -- as a matter of fact, just leave them on (you should feel a breeze coming through the doorway at all times). You could probably use a couple of $10 box fans. The idea is to create positive pressure on the stage side of the door, then -- when you inject the smoke via DMX -- it will immediately follow the airflow through the doorway. If you wanted to get really fancy you could hook the box fans up to a DMX dimmer box and control fan speed....good luck! m
  6. lwinters630

    lwinters630 Well-Known Member

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    west of Chicago
    You will need larger volume. Imagine starting with a pre hung door. Around the jam (sides and top) build a 3 1/2" × 3 1/2" empty space.

    Or If you're using Hollywood flats skined with 1/4" on both sides then all you need is connect your 3" fog hose into the empty wall cavity. Be sure to connect the cavity over the door and down the other side.

    Around the door jam where you want the smoke to come out, cut slots or drill 1" holes into the wall cavity. This may be located so it is hidden when door is closed. Cover with mesh tape paint to match trim.

    Turn on fog and it flows out around edges of door. For more fun add some led tape or led christmas lights (flat top) to create that glow with the smoke.( 1/4 hole and hot glue to mount)
    RonHebbard likes this.

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