AIEL Shop Tips
PAR LIGHT OVERHAUL
The PAR is the basic lighting fixture of the entertainment lighting
world, especially for the touring musical act. It is a simple fixture
typically consisting of an outer shell gel frame holder, and lamp
access, electrics, a PAR (Parabolic Aluminized Reflector) lamp
and a yoke. The fixture itself has no reflector or lens as these are
integral to the lamp, although there are some models where the components
are separate. Sockets are usually medium screw base, medium side prong, or
mogul end prong, although some use screw or spade terminals. LED models
have a plate in place of the lamp. On this are LEDs arranged in rows,
typically every third one is red, green or blue for colour mixing purposes.
Each lamp comes with a specific lens which may give a wide flood, medium
flood, narrow spot or very narrow spot as the most typical beam spreads.
There are others. Wattages range from 30 to 1000, but the typical stage
units run from 90 to 1000, with sizes for these being PAR 38, 46, 56 and
64. The size numbers are based on an old measurement system of eighths of
an inch. Thus, the ~200 millimetre PAR 64 has a bulb face in old
measurements of 8 inches.
INFORMATION BELOW MAY NOT BE REPRODUCED
WITHOUT PERMISSION FROM THE AUTHOR ©
Be aware that neither Atlantic Illumination, nor its owner or
employees will be responsible for any problems encountered as
a result of following or not following the procedures here. This
is strictly a guideline. You must decide the suitability of the
instructions and be responsible for the results of your work.
PAR fixture maintenance is the simplest of the lot. This article assumes
the fixture a non-LED model and is to be completely refurbished, and thus
will be disassembled. However, you may only require to do a part of what is
outlined here, so simply skip to the pertinent section(s). The instructions
on this page can be adapted if you have LED models. Essentially, one would
remove the LED plate and electrics and follow the rest of the overhaul
Read through this article before starting so you'll have an idea of what
is required. You may find that some steps are better done out of order
for your particular model. Also, make notes or drawings, or have another
unassembled fixture available for ease of re-assembly if you are unfamiliar
with the particular model on which you are working. However, given
the simplicity of the fixture, this will only likely be required if you are
completely new to fixture maintenance.
Set up a work space with proper lighting and the tools required. See
our Work Area Setup article to help with this.
Have some numbered containers available in which to place the parts from
each disassembly step. This will benefit you when it comes time to put the
unit back together again. Lay some clean newspapers on the bench to protect
both the bench and the fixture. The light colour also helps to contrast
small parts which may be dropped during the overhaul operation, and makes
for a nice work surface.
You should have these items available:
- Screw Drivers
- Nut Drivers
- Rubber Mallet
- Electric Drill or Bench Grinder
- Brass Wire-Brush Drill Attachments (Small and Large)
- Crimp Tool and Connectors
- Emery Cloth
- Wool Soap Pads (*Not* Steel Wool!)
- Narrow, Metal Paint Scraper
- Scrub Brush
- Tooth Brush
- Dish Detergent
- Electrical Tape (White and Black)
- Permanent Marker (*Not* Water-Based)
- Heat Shrink
- Heat Gun
- Spray Paint (Heat Resistant for Metal)
- Light, Spray Oil
- Spray Silicone Lubricant (Industrial Grade)
- Varsol (Paint Solvent)
- Methanol or Rubbing Alcohol (To be used with caution -- see text)
- Glass Cleaner (To be used with caution -- see text)
- Paper Towels
- Suitable Selection of Replacement Parts
- Numbered Parts Containers or Muffin Pan
A reminder that if you are new to this to keep track of the disassembly
by making notes, using numbered containers or a muffin pan to hold the parts
removed during each step, and by having an assembled fixture available for
These instructions are for working on the larger PAR
fixtures that have push-on/pull-off sockets. For LED
or screw-base units, modify the instructions accordingly.
With a room-temperature fixture, first place it on the bench in an
upright, face-down position. Most have an access door at the rear. Open
this. Be cautious: Some poorly designed fixtures only secure the lamp
via this door. Opening it may send the lamp crashing to the floor if
the fixture is in any position other than face down.
Carefully pull the socket free from the lamp's connectors. Hopefully,
it won't be seized. If it is, you will need to turn the whole unit in
such a way that penetrating oil can run down into the socket. Let this sit
for a while and try to disengage the socket again. If it's completely
seized and the socket is of the type that is bolted together, unscrew these
bolts and separate the socket halves. You will then have to work to
separate the contacts and the end prongs of the PAR lamp.
Be prepared that you may have to destroy the lamp, the socket, or both
if they have become welded together. This is particularly so if the socket
halves are riveted together. If you can, try to save the more expensive
lamp unless it is burnt out.
Now remove the lamp. This is done either via holding back a release
while the lamp is taken out, or a retainer ring must be squeezed and removed
past nipples in the side of the lamphouse. Then the lamp may be removed.
Place it in your safe place, as discussed in our
Work Area Setup.
For those models of PAR fixtures that use ellipsoidal- or fresnel-style
lamps and sockets with separate reflectors and lenses, you will have to
remove each separately. Place breakables in your safe spot.
During this procedure, don't be worried about touching the bulb. You
will be cleaning it later. Put the lamp or assembly in your safe place.
Now detach the yoke, remove any clamp or stand adaptor, and place them
aside. You may prefer to do this step before lens and lamp removal, which
is fine. Just be sure to protect the lens and lamp from damage. With some
models, the removal of internal nuts may be required to get the yoke free.
In that case, the lamp will have to be removed first, anyway.
Remove the electrical plug, if possible. Take off the electrical cord
connector. Most PARs allow removal of the socket and wiring this way. It
is done by having the line cord pull through the body, permitting the
socket to be taken out with line cord intact. For those fixtures with
moulded plugs, you will have to decide if you want to remove the
electrics or tape them up for the fixture painting phase of this
After pulling the cable out, remove the strain relief. Now remove the
lamphouse access cover (door) if possible. This step may be unnecessary
if the fixture is in good shape. Otherwise, for straightening or for certain
other maintenance purposes, it's handy to not have to deal with an access
cover flopping around. If the hinge is welded and the pin cannot be removed,
the access door will have to stay with the main fixture body for the rest of
Remove any remaining brackets. You should now be left with just the
INSPECTION and RECONDITIONING
Look at the body to see if there are any dents or bent parts. Repair as
necessary. To pound out dents, use a wooden form and rubber mallet to
lessen metal damage as compared to a direct hammer blow. Inspect the screw
mounts for the yoke; they should not be worn or damaged. If so, then it
means a trip to the machine shop to have it re-threaded. Note that some
models use a "grab plate" locking nechanism, so the yoke mounts are free
to pivot, thus stripped screw mounts are less likely to be a factor.
Do the same for the yoke. Note any burrs that should be filed off, and
then straighten the yoke, if necessary.
Now place the body into a plastic set tub or use rubber mats to protect
an enamel one. Scrub the unit using hot water and dish soap. Use a tooth
brush to get into small areas. Remove rust with a wool-type soapy scouring
pad. For stubborn rust, use a sanding sponge or emory cloth. Rinse. (A
one-metre length of garden hose is good for this.) Dry with an old towel.
Don't use a new one as some rust will likely come off. Hang the unit up
to air dry inaccessible areas. Repeat this procedure for the yoke.
For a severely corroded body, and for tarnished hardware, employ a narrow
paint scraper and use a bench grinder with a wire brush to buff the
finish. A brass brush is preferred over steel. If no grinder is available,
use an electric drill with a lockable trigger. Clamp the drill into a vise.
You will likely find that clamping the drill and holding the parts against
the rotating brush works better than clamping the parts. It saves having to
clamp and unclamp each part, and having to put the drill down to do the
re-clamping. Use a pair of pliers, preferably the locking type, to hold
small parts. This will give you more control and also keep your skin away
from the rotating bristles. Work gloves are recommended, as are hearing
protection and goggles or a face shield.
(You might now wish to skip to the "Painting" section so that the first
coat on the fixture body will be drying while you continue with the steps
Clean and buff all metal hardware including the pipe clamp or stand
adaptor. Take the clamp apart to do this. Repaint as necessary. Replace
any severely rusted parts. Oil the hardware with a light machine oil.
Polished aluminum can be buffed with fine steel wool or a commercial
PAR lamps may be washed in the sink with soap and water. If reflector,
lamp and lens are separate, wash each in turn. Wool soap pads may be used
on metal reflectors, but test on the rear to confirm it won't scratch the
surface. Use a circular motion. If it polishes with a minimum of scratches,
do the same on the front. You will have to decide if it's better to have a
smooth but tarnished reflector versus a shiny, scratched one. I vote for
the latter if it reflects more light without too much scatter, rather than
leaving it tarnished. Rinse and dry.
For glass reflectors and lenses, use only soap and water and clean hands.
Watch for rough edges that might cause cuts. Some glass optics will have
coatings that increase their efficiency. These can be destroyed if glass
cleaner or alcohol are used on them. Use only soap and warm water.
Whatever the material, when finished rinse and air dry. Place glass
items into your safe place with cloths or paper towels protecting them.
Move to the socket assembly. Inspect the contacts. For side and
end-prong versions, this can often be done by removing the screws and
separating the socket halves, unless rivets were used. If it comes apart,
the contacts will be completely exposed. Burnish off any corrosion there
and inside the socket halves. If the contacts remain severely discoloured,
you should replace the socket. For screw-base versions as would be seen in
a PAR 38, use a smaller drill attachment to allow access right into the
socket. PAR 36 models often have slip-on connectors or ring terminals. The
latter can be burnished with the electric wire brush. Slip-on contacts are
harder to access, though. Given their low cost, they can be replaced using
a crimp tool. Be sure to buy the right size and type to fit the lamp's
Should the line cord be melted, frayed, or brittle, it will require
replacement. Some may use fibreglass sheaths. Replace or repair as
necessary. If the damage to this is external to the fixture body, you may
use electrical tape or heat shrink. If it's internal, cut off the bad part
and slide a good section inside. Make up the shortfall on the other end
with an appropriate length of sheathing coupled via heat shrink or
electrical tape. When the light is fully assembled, the sheathing should
run from the socket assembly, along the line cord and into the plug at the
If the fixture uses asbestos wiring, install a new line cord. Asbestos
conducts electricity when wet and is hazardous to breathe. Put the wiring
into a plastic grocery bag and send to recycle or to your local Hazardous
Should any parts be rusted or discoloured (other than electrical or
the reflector), painting will be required. The usual colour would be flat
black, which I do recommend for all interior parts in order to minimize
unwanted reflections. The interior paint should also be one which can handle
directly radiated heat, such as barbeque paint.
However, you may consider another colour for the exterior to dress the
light up or to better identify your lights from those belonging to others,
and to give your show a uniqueness. Even so, try to stay with a darker
colour to minimize external reflections. I recommend a satin (semi-gloss)
finish regardless of the colour chosen. Now, gather your paint materials
as per the preliminary list near the start of this article and do the
Being sure it is dry, place the body in your paint booth or area, as
discussed in the Work Area Setup. Note that
natural and polished aluminum will need to be dulled with sandpaper and
a base coat (aluminum primer) applied before the final colour is put on.
If you intend to leave this finish, polish it with fine steel wool or a
fine sanding sponge.
Shake the spray paint can well and begin to coat the interior in even
strokes, stopping the spray at the end of each pass and then re-starting as
the stroke returns. If the exterior colour is the same, you may also coat
accessible areas at this time. Keep the coat thin. Allow it to dry and then
do a second or third coat, if necessary, following the instructions of the
can regarding re-coating. Use paint solvent to clean overspray. Allow to
dry. Repeat for the yoke and any other parts requiring paint.
If the exterior is to be a different colour, after the interior has
dried, coat the former using the technique above. Keep overspray to the
interior to a minimum. You may have to touch up the inside after the
exterior has been completed. Allow to dry overnight to get a harder, more
REASSEMBLY and LUBRICATION
You should now have a number of sections and parts which are clean,
non-damaged and possibly repainted. Being careful of your new paint work,
start to reassemble the fixture in reverse order, beginning with any
internal sections. Regarding paint which is dry, but fresh, it may take
a day or so for it to harden completely, hence the caution when handling.
Reinstall the socket assembly along with any strain reliefs and pull the
cable through the body. Ensure any outer covering or sheathing goes inside
the plug's strain relief and tighten all body and strain relief screws.
Adjust the sheathing so that the slack goes inside the PAR body and up
to the socket. Tighten the socket strain relief if one exists.
Replace any internal brackets or fittings and lubricate all hardware with
a light oil. Keep oil from soaking into your work bench. An oil soaked bench
is not a good environment for lighting fixtures because it will work its way
into areas where it is not wanted.
Restore the lamp. If the reflector. lens and lamp are separate
components, clean the quartz bulb with methanol alcohol to remove finger
oils. PAR lamps may be cleaned with soap and water or glass cleaner, as
discussed earlier. (Silicone may be necessary. See the "Alignment" section
Do the final assembly using the remaining parts, but you may elect to
leave the yoke and pipe clamp off until after testing is done.
No alignment is required for PAR fixtures because the lamp/reflector/lens
is a pre-aligned unit. However, test the light. Shine it onto a white screen
and check the focus. Most PAR lamps have an oval beam pattern and can be
rotated to align that pattern with what is being lit. Confirm that these
lamps can rotate freely. If not, silicone the edge of the bulb where it
contacts the fixture so as to allow smooth turning. For fixed lamps, such
as PAR 36 and 38 models, ensure that the socket and/or lamp is seated
properly to allow the light to exit the fixture in a straight line without
shining on to the fixture's interior on the way out.
For separate components, be sure the reflector is seated properly and
that the socket and lamp are aligned within the reflector. Test that the
lens can turn freely. Silicone the lens edge or rotation mechanism for
You now have a clean, operating, properly aligned
fresnel fixture ready to work for you. ENJOY!
But wait... don't enjoy too much. You have more
lights and equipment to overhaul. (-: