How to: Tech -
Platforming, things to stand on, stage decks, etc.
Written by Michael Powers
Monday, 18 December 2006 01:55
Techie's Corner As a continuation
of last month’s column about "Rain On Stage", this month’s column will
focus on water on stage. Specifically, water in sinks. Next month, I
will wind up this topic with a discussion of other types of water such
as hand pumps, fountains, waterfalls, pools, etc. The basics for water
in sinks are the same 6 major areas of consideration as for rain.
Supply, storage, delivery, recovery, control, and water quality. For an
in depth definition and explanation of these six areas, check out last
month’s column under TRE back issues, December ‘98.
Probably the most
common water FX asked for or required by scripts and directors is a
sink, usually a kitchen sink. For a sink, supply and storage are
virtually the same thing and delivery is often combined here as well.
Recovery is usually, but not always, a five gallon bucket under the
sink drain. Control is basically making all your plumbing connections
and joints water tight with no leaks. Water quality is very important
as water from a sink is often consumed. However, as the performer is
not immersed in the water, heating it is rarely necessary. Delivery,
while usually simple is the biggest variable. The three most common
forms of delivery to a sink are: 1. A hose from a backstage faucet or
sink. 2. A barrel or container higher than the sink using gravity for
the delivery pressure. 3. A hudson sprayer or similar, with the wand
removed, hooked to the sink
Other less common methods
include: 4. A pressured water tank with a connection to a separate air
tank or compressor for the delivery pressure. 5. A commercially
manufactured Precharged Diaphragm water tank. When installing a sink on
your set, the first thing to do is to adapt the faucet inputs to the
type of plumbing you intend to use. This step is the same for all
methods of water delivery. The most common and the easiest to use is
the common garden hose type of fittings. In the laundry plumbing
section of most hardware stores there is a shelf of various fittings to
adapt different types of pipe fittings to hose fittings. The fittings
on the sink you have will determine just which adapters you will need.
Once the sink has been fitted with adapters the next thing to attach is
a "Y" hose which is just what it sounds like, a "Y" shaped section of
hose with fittings at all three ends.
The "Y" hose is kind of like a
two-fer for water, it splits up your water and sends it to both the hot
and cold faucets on your sink. From the "Y" hose you then can run a
hose to your source of water. Of the first three methods of supplying
water, the hose to a back stage sink is by far the easiest. The water
is supplied clean and under city pressure. It doesn’t need to be
treated or filtered. The draw back to this method is that if there is a
leak, the supply of water is unlimited. If the hose runs where it is
out of sight, quite a bit of water can run out before anyone discovers
the leak. It also means that, unless you can run a second hose to the
back stage sink supplying the water, your supply may exceed your drain
container. It can be very disconcerting to have the actor turn on the
faucet and have water start running out from under the sink cabinet. In
addition there are times when the set is in the round, on a turntable
or a rolling wagon or some other configuration that prevents you from
running a hose to the sink.
The second method, a container that drains
to the sink is also very easy to do. The container is simply placed on
a platform, backstage landing etc. that is at least six to eight feet
or more, higher than the sink . The container holding the water can be
a 55 gallon barrel or a 5 gallon pail. The main thing is that it must
be very clean. If the container is washed and refilled every day,
treating the water is unnecessary. Otherwise it should be treated for
purity, much as you would treat drinking water on a camping trip.
Purification tablets are available at any good sporting goods store.
Because stages are notoriously dusty and dirty, because stagehands and
electricians working over head can always knock down dirt, spike tape,
snow from last year’s Christmas Carol or Nutcracker etc., any container
should always be covered. The advantages of the gravity feed are
simplicity in plumbing, limited water supply in case of a leak and it
is very inexpensive. The easiest way to run the water from the
container to the faucet is simply siphon it. Of course you will need to
clamp or fasten the hose in some way to keep the end at the bottom of
the supply container.
If the water is consumed in quantity, I suggest
acquiring a "potable water" hose from a RV dealer. Some hardware stores
will carry this type of hose but not many. The potable water hose is
not a necessity for a short run or when the water is used for washing
or a small sip, but it will make the water taste a bit better.
Otherwise a ordinary, clean, garden hose or laundry hose will do fine.
If you want to drill a hole in or near the bottom of the container and
install a hose bib or faucet, that is fine and does allow you to shut
off the water from the off stage side if needed. PVC valves are easy to
work with and can be purchased at almost any hardware store today.
Brass or copper valves cost more if you buy them new, are more
difficult to work with but are far sturdier in any situation where
physical abuse or contact takes place. Iron valves work, are cheap, but
they will rust and put a distinct metallic taste in the water. If you
have never done plumbing work or don’t have someone available who has,
I would not suggest this variation. If you want to try it anyway, a few
hints are in order. First, use plenty of teflon plumbers tape on any
pipe thread joints.
Second, While I do advise using pliers or channel
locks on hose fittings, remember that too tight will produce a leak
almost as often as too loose, for this purpose, hand tight and just a
tad more is what you are aiming for. Third, all hose fittings require a
washer, I prefer rubber but the plastic or other types supplied with
hoses are just fine. Fourth, tape of any kind or silicone caulk and
similar sealants will never stop a leak when placed on the outside of a
hose, joint or tank. Another way to install a valve between the tank
and the sink is to get a ball gate valve. It will have pipe threads at
each end and a lever type handle. When it is turned 90 degrees it is
full open or full closed. These are available from Grangers, McMasters
& Carr et al. and better hardware stores. You will have to find
adapters to change from the hose threads to pipe threads and back
again, but it will allow you to shut off the water from back stage. The
major disadvantage of the gravity feed system is that water is HEAVY!
Any platform built to hold a water container must be very sturdy. Any
slight bump can start the water sloshing from side to side and if the
platform or container are not stiff and sturdy, the result can be a
disaster. Water weighs 8.322 pounds a gallon, 41 pounds for five
gallons, and 458 pounds for a 55 gallon barrel. The third method of
providing water to a sink is the altered Hudson sprayer. By "Hudson
Sprayer" I am referring to any of the hand pump type of garden sprayers
available at hardware/lawn and garden stores, Hudson and Chapin are two
of the best brand names, but any of them will do the job. To use one of
these units you must first remove the wand and valve or cut the hose
near them. This will give you a rubber/plastic tube about 1/4" to 5/16"
inside diameter. Insert a hose barb into the end of the tube and secure
with a hose clamp. (illustration #3) Hose barbs come in a variety of
sizes and styles. The barb section must fit the inside diameter of the
hose from the sprayer you are using and the thread end should be male
hose threads to fit a standard garden hose fitting. Once you have the
sprayer hooked up to the back of the sink, simply fill it with water to
the fill line, put the top on and pump till the desired pressure is
reached.
The advantage of the sprayer method is that it is easy, cheap,
self contained and has a good pressure. The disadvantages are that the
volume of water is limited, the largest sprayers hold 2 gallons or less
of liquid, and the pressure drops off rapidly the water is used up. If
your needs are more complex, you may want to resort to more complex
methods of providing water. The most usual reasons for needing "other"
methods of producing water are turntables, cut-a-way sets and theatre
in-the-round or extended thrust. In all of these situations, a hidden,
self contained unit it needed. If the amount of water necessary is
small, the hudson sprayer is an excellent method. For situations
requiring more water or sustained pressure the two methods mentioned
earlier are very good. The first, a water tank and an air tank, is
especially suited to a situation where your space is oddly shaped or
very limited. In fact, I am using this method on our stage at this very
moment. The show is "Having Our Say" and is done on a turntable with a
cut-a-way set.
They actually cook a meal on stage so all but two of the
cabinets must open and be used, and they use 4.5 gallons of water. The
two cabinets that do not open are used for the waste water so the only
place left is the space between the walls of the two sets. The
available space is 10 1/8" wide. The solution was to make two tanks out
of PVC. One for water and one for air. The PVC used is schedule 40,
rated at 260 psi at 180 degrees fahrenheit temperature. When using PVC
for a pressurized system, all fittings and joints must be made at a
professional level, anything less will leak air or water. For the
system I am using now, the water tank is 6" i.d. at 48" long, which
contains slightly over 5 gallons of water. The PVC fittings needed to
build the tank have an outside diameter of 8.5" so 6" i.d. is the
largest pipe that would fit inside the walls of this set. The tank is
constructed with an end cap at the bottom with a hose bib faucet
installed in the end cap. To install the hose bib, the end cap was
drilled to 45/64" and tapped to 1/2" FPT.
Even though teflon tape is
not required for this joint, I strongly recommend it as it prevents the
possibility of the threads spalling or cracking if you have to remove
the faucet in re-insert it for any reason. At the other end of the PVC
pipe, a 6" slip fit socket to female pipe thread adapter was attached.
The cap was then constructed from a 6" male pipe thread to slip fit
socket attached to a series of bushings, adapters ending in a shutoff
valve and a female hose fitting. Just below the top of the tank there
holes drilled and tapped for a pressure gauge, air input and a bleeder
valve. (illustration #4) The reason for the 6" thread and socket
adapters is so the water tank can be opened up and cleaned before and
between uses. This is very important as a closed tank will grow a
forest of mold and bacteria in the months or years between shows that
need a sink. The air tank is simply a 4" section of schedule 40 PVC 4’
long with end caps at each end and drilled and tapped for an air input
and a tank pressure gauge. To complete the system simply install an air
in put valve, a "TEE" fitting a regulator and a hose to the sink.
(illustration #5) The main advantage of the twin tank method is that
you can design the tank size and shape to suit very unusual situations.
The last method I will touch on is the use of an accumulator tank. An
accumulator tank is a device used in residential water well systems.
Check out your Granger catalog under precharged water tanks, a 2.1 gal
tank is part # 3P676. Basically an accumulator tank is a two part tank
with a rubber diaphragm dividing it into halves. A precharged tank has
one section of the tank pressurized and sealed. When you fill the other
half of the tank with water under pressure, it further compresses the
air in the first chamber. The valves are closed and the water source
removed. Then when you release the water into the sink, the diaphragm
section provides the water pressure. In some ways it is like the hudson
sprayer method except that you don’t have to pump it up. In some ways
it is like the twin tank method except everything is in one container.
Some of the advantages are that the water supply can be quite large,
these tanks come in capacities to from 2 gallons to over 300 gallons.
The cost ranges from $45 for a 2 gallon tank to $5,600 for a 370 gallon
tank. The disadvantages include the shape and size. They closely
resemble a large compressor tank of a comparable volume, basically
short, squat cylinders. Another disadvantage is that they are designed
to be always filled with water. In the theatre we will use the tank for
a few weeks and then it will be in storage for weeks, months or years
between uses. Even if it is cleaned with bleach and dried very
thoroughly, the probability of mold or fungus etc. growing inside
during the storage period is quite high. ---
Michael
Powers is the Technical Director at The Meadow Brook Theatre, a LORT B
theatre in Rochester, Michigan, a Detroit suburb. Prior to The Meadow
Brook Theatre, Michael has worked at such theatres as Geva in
Rochester, N.Y., The Lyric Theatre in Oklahoma City, The Cherry County
Playhouse in Traverse City Michigan, The Walnut St. Theatre in
Philadelphia, The Pittsburgh Public Theatre in Pittsburgh and Wild Wood
Park For the Performing Arts in Little Rock.