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is it wrong repainting ellipsoidals?

Discussion in 'Lighting and Electrics' started by Les, Mar 20, 2005.

  1. Les

    Les Well-Known Member Premium Member

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    I have some 360Q ellipsoidals at home that need a few parts and I'm slowly getting them up to performance standards. I was wondering if its wrong to repaint them. I know there is a difference between normal and high temp paint, but I don't really like how hi-temp paint looks. It always goes on somewhat uneven and turns out chalky. Do you think a regular semi or high gloss black spray paint would work if I allowed it to cure properly and followed a burn in cycle?
     
  2. avkid

    avkid Not a New User Fight Leukemia

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    To me, yes. But this sound like a question for Mr Shipinski.
     
  3. techieman33

    techieman33 Well-Known Member

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    I don't think it's really worth taking the chance. But I agree this is probably a question for ship to answer.
     
  4. falcon

    falcon Active Member

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    as long as you don't paint anything that isn't suppose to be painted and teh paint can stand the high temps teh fixture reaches, i see no problem with it. but I would have to agree with everyone else that Ship is the best person to answer this
     
  5. Mayhem

    Mayhem Senior Team Emeritus Premium Member

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    In my opinion, it is only wrong to paint over the name of equipment that does not belong to you and then claim it for your own. However, as this is not the case here, my answer would be NO, it is not wrong to repaint.

    In fact, it is common practice here in Australia (as it is I would suspect in the US and elsewhere). Equipment gets dented and scratched from time to time, regardless of how careful we might be. Scratches will expose the metal, which will result in rusting or corrosion and if not kept in check can mean the end of the road for your gear.

    Maintenance of your inventory should not be limited to checking for faulty wiring, cleaning lenses and reflectors or vacuuming out the dust. It should also include fixing any signes of rusting/corrosion.

    I tend to use a flat black paint for PAR cans as they tend to get knocked about a bit, so touching them up is easier. However, there are self etching paints on the market that mean that you no longer have to sand the fixture before painting (other than to remove rust or corrosion).

    I have been in a similar situation to you where I have picked up damaged fixtures or combined spare parts to get a working unit together and then had it powder coated. A little more expensive but I have found that the result is better and more durable. However, probably not worth it for fixtures that get knocked about a bit or will not be seen once rigged. I have some cans, Fresnels and QI’s that have been powder coated and are mainly used for up lighting, so these are in visible positions.

    Unless there is a need (rust etc) I wouldn’t worry about painting the inside of the fixture and care should be taken not to get paint on surfaces other than those that you intend to. I have found that taking that little extra time to disassemble the fixture can save time in the long run.

    Not only will it keep your equipment in your active inventory longer, it will ensure that it look presentable to your clients. And sometimes, this can be a big factor. To most people, if it looks go, it is good and vice versa.
     
  6. Les

    Les Well-Known Member Premium Member

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    I have about 6 of these lights and one of them has no lenses or lamp housing so I used it as a test piece. If these get rigged, they will most likely be in a high profile position, so it would be important for them to look nice, but not necessarily blend in with the surroundings. I chose high gloss black, and I really like the new clean look it gives them. I think that the smoother finish may be easier to keep clean too. I was thinking about cutting down the lens barrels to convert them into 6 x 9's (these are 6 x 12's) but I then realized that I would probably need a whole new set of lenses per light. So I'm glad I didn't just dive right into it. By the way, some of these lights have bad shutters but I cannot figure out how to get them out without destroying the blade. If I do so, how do I get a new one back in? Do they come unassembled, and would I need to pop rivet the insulators on? Also, one other thing... Would you think it's necessary to buy the upgraded reflectors? The current ones have no visible signs of damage so I'm not sure if it's worth the money.
     
  7. cutlunch

    cutlunch Active Member

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    When you repaint just make sure you mask off any information plates so they don't get painted over. I am thinking of info plates with make, model, lamp base, lamp type , wattage etc. I know, from experience, it is a pain with older equipment when someone does this and you have to hunt for this info. Sometimes if this is a discontinued product it can be very hard to get accurate info.
     
  8. Mayhem

    Mayhem Senior Team Emeritus Premium Member

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    Great point - since I bought my digital camera, I have been taking pictures of such plates and in some cases stickers and keeping them on disc. Prior to that I always typed the information into my inventory database (actually I still do in addition to the picture). I also keep fuse sized and values stored as well, just in case. My philosophy is to keep as much info as possible, as you can always ignore it later but not necessarily find it again.

    With regards to your other questions: I know almost nothing about ellipsoidals so I am going to be next to no help with the specific questions. My only thought about the reflectors is this:

    What is the advantage between the old and the new and is the price justified? Also, given your application, do you think there will be a noticeable benefit? If the answer is no, then I wouldn’t bother.
     
  9. ship

    ship Senior Team Emeritus Premium Member

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    When did my Dad join the forum, and I work for a living.

    I'm one of many seen above to have good answers and even other
    solutions that will work - also shorter answers no doubt. Hopefully I can
    add to a base of knowledge on painting some but what’s expressed is of opinion no better than anyone else’s.

    Most fixtures are for the most part aluminum thus won't rust per say but will have problems if scratched with lime coming off brick walls or salt in the air if near the sea effecting the aluminum in a rust like way. Much less paint chipping off.
    The scratches be them in metal that will rust or aluminum beyond this will look like crap if all dinged and chipped up. You have gear that looks new or well maintained, those using it (hopefully) take more pride in using it and being careful with it. Much less it looks more professional.

    On the other hand, you get too many layers or too thick a coat of paint and
    it will retain heat in either failing no matter how high temp. the paint or retain heat in causing the fixture problems.
    Paint don't stick to dirt or corrosion - surface preparation is the key.

    For stuff like barn doors that is more or less normally a baked on powder coat of paint to a flat sheet of steel or aluminum, re-painting at times won't stick unless you provide some tooth on the surface for it to stick to. In other words a palm sander with say a 80 grit sand paper will be needed to both sand down the surface and smooth out edges of what paint remains on the surface so the layers of paint at the edges are less noticeable. Aluminum Barn doors often will have problems with retaining paint short of sanding them. Just something about the smooth flat surface of the aluminum plate when heated often makes even powder coated paint just flake off if it gets hot enough. Such an effort can also be useful on lighting fixtures in both feathering the edges of paint is still sticking and what came off, if not allowing better contact for the paint.

    Light sanding can also be useful if the old paint has a glossy coating of paint that often won’t allow a second coat to stick to it. As long as the surface has been cleaned this should not be a big problem but can be at times necessitating sanding.

    Sand off any rust or corrosion until it’s to the more stain and less rust level. I prefer to use a rust reformer paint as a first coat in these areas before the high temp. finish coat. Any spray paint will help to resist rust or prevent it from spreading further by cutting off the oxygen and moisture for the most part, but if the rust was not sanded sufficiently before painting it can continue to spread under the paint. The rust reformer than as a primer coat will ensure a better adhesion to the surface and that the rust is transformed into something that will not spread. Consider rust much like mold. You can paint over the mold and often it will die other, but frequently it will still continue to grow - under that fresh coat of paint.

    I dislike using Rust-Oeum brand High Temperature Spray Paint.
    Works for many very well, just my personal opinion of it that it becomes too thick and spotty far easier than other brands. Krylon High Temp spray Paint I much prefer. Much better in providing a lighter and more even coat.

    For spray paint if possible and if a spray paint painter’s handle provides a nozzle to it, it might give a more refined or adjustable spraying than with the standard tip that comes with the can. Read directions on the can or nozzle for proper distance. Reading directions is a good thing. If you spray at the wrong distance you will get dots of paint that only sanding will remove in otherwise ruining a good coat. Might have compressed air spray nozzle with you also for blowing out a tip that is malfunctioning in a quick fix.

    Light coats can be gone over with second light coats. Once you get a drip from being too heavy, there is not much you can do about it.
    You don’t have the control of an air brush so don't use it like one with little squirts. Long strokes in starting before you hit the designated area and releasing only after you are away from it will do a better job of feathering in your coat of paint. Also have something near by to test spray first because sometimes more vehicle comes out than pigment at first and it will ruin your finish if the can is not mixed sufficiently or has a chance to balance the spray. Ta da, ta da - use a mask and spray in a well ventilated area.

    If you want a really good paint job, take it to an auto body shop for their
    pneumatic spraying and much more experience with painting. Much less better paints. That's the operation we installed at work and it's much better than spray paint both for light touch ups that make gear look new and for high temperature applications or adhesion. A few years ago I bought some used fixtures from Bash. I was very impressed with the fixtures while not new, having that new look to them by way of no doubt a similar auto shop like painting system. All fixtures at work get cleaned than if needed a very light coat of touch up pain with the above steps and painting techniques. Took a long time for us to find the right mixture of paint that would work with the fixtures but for the most part an auto shop should have the experience to figure out what will work best. Fixture paint for us comes in a 55gal. Drum.

    For new equipment that needs a color or to be come black such as on truss, we send it in for powder coating. Unfortunately it's almost cost prohibitive without a large run stuff to paint, but it is possible to do powder coating yourself with an oven - just not Mom's. A good paint store should be able to get powder coating pigment for you to bake on yourself. Such painting is not for touch up work however.

    Finally as an alternative to high temperature spray paint, it might be
    possible to purchase touch up paint from the fixture manufacturer. Don't
    know if Altman still sells their Olive Drab color, but it might be available
    thru Hub (below). Sorry no website, but it's also a source for discontinued parts if the manufacturer is out of business or stopped making the parts. Strand with it's kind of black crinkle coat paint might still also be available thru them also. This all much similar to me buying Mole Mauve thru Mole Richardson recently in making it easy to touch up parts of the paint on Mole fixtures. The Strand paint however if still available from Strand has probably changed it's color slightly in a similar way to Altman I think having various forms of Olive Drab over the eyars thus Hub as a source would be useful. (Vara-Light/Dimatronics/Hub Electric (Old parts Dist., ?Owned by Altman) 6207 Commercial Rd. Crystal Lake, Il. 60014. (815)455-4400)

    Always a shame when someone tries to paint over the really old
    Altman Olive Drab - it always seems to make the paint under it peel off due
    to the thick coat of paint already on it, much less there is something to be said about the classic fixture if in mint condition.

    When necessary to paint, you probably do want to pre-sand if not send it in for a sand blasting. This especially in the form of a more artists set up for a sand blaster than that a house painter might use. Control is the key.

    This would do a good job of surface preparation also. If restoring an
    antique fixture, I think going with the original color or if the fixture is not that bad in chipping, leaving it alone would be better. In the case of some rust but not that much and in general paint in decent condition, for my Mole Lights I was using a clear rust reformer, though I will be darned if I can find any more of it. In this case it was used inside the Fresnels but only because after sanding the surface was still dark. Unless your inside of the fixture is
    dark or covered by a reflector, painting the inside of it might be a good
    idea to absorb light rather than reflect it.

    Worth a test would be if a flat or semi-gloss black rust reformer will take heat well. Just bought some from McMaster Carr in spray paint form but have not had a chance to test it. Given the tooth the rust is going to give to the paint, on a light coat, it might do a good job with heat.

    I agree with Mayhem and others on taking the fixture apart, much less tapping/masking off what you don't want painted. To a certain extent a rag will wipe clean what should have been masked, but one should not depend upon getting to this area to clean up in time. Goof Off will also help clean areas that should not be painted such as name plates. It’s truly the work of an armature that’s too lazy to protect what needs to be protected.
     
  10. ship

    ship Senior Team Emeritus Premium Member

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    By your hints, I’m guessing you have Altman 360Q luminaries. I took some photos today that hopefully I will be able to post on my own.

    First the easy on what needs replacement verses what to watch. The Altman website like that of ETC has exploded pictorial drawings in liking parts with photos.

    The old reflectors are no longer available in having been upgraded. Rule of thumb is to use what you have until it burns up or is no longer able to become clean in reflecting well. At some point there will be a seeming film on the older reflectors that just won’t come off. Stainless Steel/Aluminum Polish cleans reflectors well often beyond what glass cleaners can do, as long as it’s not a cream based pumas filled metal cleaning product that will scratch it. The new reflectors should take both heat and protect against what seems like ozone better.

    [​IMG]

    Same with lamp bases. While you should inspect the lamp base and lamp closely every time you change lamps to detect a problem, and have a spare lamp cap/socket assembly with base and plug readily available should one show signs of a problem, use the old lamp bases up as a cost effective solution than buy the upgraded 250c/1000w version. I don’t think that even the low heat normal bases will be a question of too small a wire gauge for the wattage of a lamp as the case with a ETC S-4 fixture that used 18ga wire for the original ten year run of 575w fixtures before 750w upgrade. The Altman bases should all be rated for a minimum of 750w. Such even original lamp bases/sockets if you don’t do much of any swapping of lamps between fixtures can often last years. I think it more a question of not well seated and swapping of lamps between fixtures that causes many to go bad. The old style socket also needs to be watched in that it’s SF-2 silicone wire conductors will often shrink/melt when over heated in leaving exposed conductors near the lamp base assembly. The newest high temperature “TP-22" lamp base in having 250c wire, and rated for 1,000 Watts and with a added fiberglass spaghetti tubing over the conductors should have these problems solved and is worth the few more dollars more in investment. Got rid of the aluminum heat sinks and went with a engineered porcelain to dissipate the heat instead on the high temp. premium sockets.

    [​IMG]

    Other things to watch is the yoke mount. If old style, keep a few replacement yoke locks (die cast friction washers) in stock if not possible to convert to the improved yoke lock. The old system is a bad design that easily breaks when people force the fixture without adjusting the thumb screw.
    The below upgrade kit if afforded is a good solution.

    [“The head assembly was modified for the 360Q in 1990. The old style was a straight yoke that used 2 die cast friction washers between the inside of the yoke and body, and two 5/16" T-Handles. The friction washers are available as #12-0012 and the T-handles are available as #37-0025. The yoke is no longer in production. Old style heads can be upgraded to the new style by ordering #95-0199 upgrade kit.
    Included in the kit:
    1) #95-0152 Yoke Assembly, 2) #20-0124 Locking Dog Discs, 6) Mounting Rivets, 1) Template, 1) Instruction Sheet.”]

    Other things to look at is where the lens train #70-0026 meets the gel frame holding front #22-0129. I have seen a few instances where they have snapped this weld or the bend that holds the gel frame itself gets fatigued to the point of breaking. Also look for stress fractures where the pineapple / bell #12-0002 heat sink hinges to the gate assembly #12-0132. Should it be cracked it won’t be safe for use in the inventory.

    [​IMG]

    How to change the shutter assemblies or if you need to at all.

    Start by looking at the screws that retain the gate assembly and testing to see if they show signs of rust or can easily be removed. If rusted or not easily moveable some “Liquid Wrench” on the hex head sheet metal or thread forming screws that hold the gate assembly to the aluminum casting will be necessary. (Forget which type of screw is in use) This should be applied both to the inside and outside on the screws if stuck. Let it soak in to prevent the screw head from sheering off and leaving the screw body inside the fixture.

    Vise Grip one at a time the fiber washer handles on the shutter, and lock the Vise Grip in a bench vise or have a friend hold it. Than drill out with a 5/32" or 1/8"#30 drill bit all rivets that hold fiber washer to shutter. Dependant upon the era of the shutter. Start with either a #30 drill bit or 1/8" and move up to the 5/32" to remove the fiber washers. Be careful in drilling because some times the drill bit will either not stay centered on the rivet, or can snag the fiber washer handle or shutter itself in whipping it around at high speed. Grinding away the rivets or breaking off the fiber washer than grinding away the rivet is another option. Do not attempt to use sheet metal sheers to simply cut the shutter blade, the steel is too hard for this.

    Two of the four shutters won’t require removal of the fiber washer/handles to extract the shutter, but it’s easier in general to just remove all fiber washers before taking apart the assembly. Some of these fiber washer handles if lucky when drilling them off might also be re-usable. On the other hand there is about four different versions of this handle. The first has a 1/8" hole on it and fairly thin fiber washers. Second was 5/32" hole in the handle and thicker, a improved type similar to this and still available is a more thermoplastic type of washer for a handle with the shutter sandwiched between. Finally I’m reading in the fixture notes #14-0090 is a “single piece, molded finger grip” - though I have never seen one. The original thin fiber washers might not work as well with more modern shutters. The purpose of saving old fiber washers would be for use as replacements to other fixtures. Either of the two more modern thermoplastic washer/handles will hold up better and should be used with new shutters.

    Of note on these factory parts is that when you purchase them is while the drawings imply it’s say a set of four, often you will only be purchasing individual parts - not a set. In other words, you not only need four shutters (verify this part is a set not individuals with the retailer) you also need eight thermoplastic washer handles or new style single piece ones and four 5/32" aluminum head & shank rivets from them also. I have gotten caught in the past by thinking I’m purchasing a set and only getting one piece.

    General note on if the shutters need replacement or not. Discoloration of the metal in the shutter is a first sign of heat, it than will loose it’s gloss like finish followed by the metal bending and burning away. If the shutter is only discoloring, a fiber or even cotton buffing wheel can to some extent re-finish the surface of the steel to some extent that with a coating of graphite (below) can make the shutter last a little longer. In changing colors it’s lost it’s temper and will not last a huge amount of extra time but will to some extent. In the other two cases, the shutter is gone and needs replacement. All the pounding flat and buffing in the world will not make it last significantly longer. At other times a shutter will get a ding or bend in it’s blade. It’s unfortunate and happens when someone attempts to force a stuck shutter blade that has slipped between plates. Once the shutter blade loses it’s flat edge, that’s the point heat will attack first in destroying the shutter blade. It might be possible if a dinged blade to pound it flat than grind a new flat edge to the shutter blade as long as doing this is before heat damage has been done to the shutter and this grinding also does not cause heat damage to the shutter. If doing so this new leading edge of the shutter blade needs to be perfectly smooth or those rough edges will retain heat or in melt faster.

    [​IMG]
    [​IMG]

    Use a marker to designate a witness mark for alignment of the ring for proper orientation upon re-assembly. Sometimes the screw holes otherwise won’t line up. Now remove the #30-hsw0606-23 screws. Pull out one section of the gate assembly at a time and replace the shutters with new shutters by pushing them into the center of the fixture to remove. Any rusting of these parts should be sanded off than crocus clothed smooth. It’s a good idea to use a coating of spray graphite on warn pieces to coat the surface and provide a more frictionless surface. Be sure to let the graphite dry and wipe off the excess with a rag. Re-assemble possibly with new screws to mount the gate. If your #20-0122 gate the screws thread into was aluminum, it’s easily stripped. If this is the case, turning it slightly and drilling than tapping new holes for it can be a good option.

    Rivet the fiber washer or handles onto the shutter blades using either 5/32" rivets provided by Altman or aluminum shanked and body rivets. Steel rivets might provide too much clamping pressure upon riveting and cut thru the handle.


    The above Industrial Grade aerosol based High Temperature Spray Graphite or Military Spec. Dry Lube will also work well on iris’s and lens trains once both are polished with crocus cloth which is a very fine sand paper. Again, the spray graphite needs to be applied in a heavy coating and needs to dry. The surplus than is wiped off.

    Other notes on fixture repairs:
    Replace standard (McMaster Carr has most of them) screws such as sheet metal
    and others if they show corrosion or it will get worse and destroy the metal
    they touch. Re-tap holes in steel and add Teflon oil to them if meant to be
    adjustable and to other working parts. (This might smoke a little if the
    vehicle in it has not dried sufficiently.) White Lithium Grease otherwise
    works well for moving parts but once dirty needs replacement. Always use
    Stainless Steel, brass or bronze in areas that it's going to get really hot
    such as in mounting or holding up the lamp base. Type 316 Stainless Steel while expensive is really useful as a screw grade for high temperature but
    don't use it for lamp base terminals. Don't forget the mica or fiber
    insulators under the base - they are important, if not also some form of
    silicone or Teflon insulator or pads under the screw heads mounting the
    porcelain lamp bases to the fixture. This will add a little bit of soft
    spring to the otherwise fragile porcelain. Stainless Steel is not as good
    for electrical current - do not use it on contacts. Avoid Black Oxide screws
    also - it's even worse for current flow much less it does not take
    heat/corrosion/moisture very well before rusting. As I found on the Mole
    Lights, one would think that corrosion resistant Yellow Zinc Grade 8 bolts
    will have done a good job in taking heat but they did not where they touched
    aluminum. Plain steel if coated with either the thread locker or Teflon oil
    it would seem hold up better as a second choice to Stainless, Brass and
    Bronze. For the lamp base, as long as they clean up, the brass or bronze
    screws are probably fine but otherwise are often easily replaced. Purchase
    of some Bronze external tooth lock washers to help keep terminals tight is
    also a good idea. For other screws that need to stay tight but don't have
    current, High Temperature Thread Locker is useful.

    Use High Temperature ring terminals on the end of the wire and wrap it's
    crimp barrel with high temperature fiberglass electrical tape to ensure it
    can't short to something. If it otherwise has a set screw terminal, use a
    properly sized ferrule on the wire. This will prevent the set screw in
    turning to apply pressure onto the wire from cutting and un-even contact
    with conductors. Where possible, if the lug the wire is to go into is much
    larger than the wire, use more than one size of ferrule. A 12ga ferrule will
    easily sleeve over that of a 14ga or 16 ga. ferrule in not only better
    sizing it for the hole, but adding a bit more metal over the conductors to
    distribute the pressure and further protect against the screw cutting into
    them.

    On the conductors themselves, 200c heat wire such as SF-2 Silicone with or
    without a fiberglass braid over it should be used for anything over say
    150w. For high output things without much cooling 250c TGGT teflon wire with
    a fiberglass braid should be used. The primary difference between conductors
    here to consider is that TGGT while it will take more heat is also less
    flexible and might not be as good for use on a whip. If looking at what your
    fixture has inside of it and you see fiberglass wire that's more tan than
    colored white or black, it's probably TGGT in use. If the wire is the same
    as that of the Luminaire cord than it probably is not unless on say a cyc
    light. There is also some 200c multi-conductor fixture wire on the market
    that dependant upon the brand will either be crappy and need fiberglass tape
    reinforcement where it is touched by a strain relief of if Rockbestos in
    brand hold up really well and be much like a SJ cable. Adding a bit of
    fiberglass electrical tape at all strain reliefs in general no matter if fiberglass conductor sleeving or multi-conductor cable will both prevent
    much of the damage to the cord because of the strain relief and if say
    1.1/2" extends beyond the strain relief it will prevent flexing which will
    also at the strain relief cause cuts. Fixture wire for large wattage
    equipment often is and can be sized one size smaller than is normal for
    amperage ratings on cable. Do not be shocked if you are working on a 2Kw
    lighting fixture and while 200c, it only has 14/3 wire feeding it for the
    whip. Where possible in the fixture use the proper wire gauge however. For
    750w rated fixtures it will normally be 16AWG, for 500w fixtures it can be
    18AWG but I would also use 16AWG. (American Wire Gauge.) Inside the fixture
    and on the way to the lamp base, you will also frequently find some form of
    fiberglass spaghetti tubing over the conductors. It can frequently be
    re-used or is easily replaced especially with a silicone coated fiberglass
    tubing. Good stuff in helping to keep the heat off the conductors. It also
    where the cable is clamped to the frame helps prevent those clamps from
    wearing into the wires. Where possible also in these areas some fiberglass
    electrical tape will be useful in preventing this wear from inner fixture
    clamps.

    Finally check them lamp base contacts really well. At some point it is
    easier to just replace the lamp bases. In the Mole Light conversion project
    you can see the difference between a good and bad lamp base but they don't
    have to even get that nasty to not give a good contact. Pitting once coated
    when below the surface and not too extensive would be preferable to grinding
    away at the oxidation which removes much more surface area than wise in that
    entire area no longer coming into contact with the lamp's pins or base. The
    less surface area you have in contact with the lamp's pins the more heat
    will build up that could destroy pinch seals or even start arcing/melting
    again on a lamp base otherwise clean. In cleaning a lamp base, want a smooth
    mirror like surface as long as it's round or flat sufficient to make good
    contact with the pins. Should you need to clean oxidation or even material
    left over from welded pins from the surface, and if you are able to get at
    the contact area a Dremmel tool works well. Use a brass brush to clean the
    base. Than various grits of abrasive wheels or tips to remove and hone than
    polish the surface. Be careful not to remove too much material or most
    especially too much material from only one area which will leave the contact
    not touching the contacts on the lamp. Crocus Cloth can also be useful to
    refine either pins and contacts on a lamp or that of the lamp base. It's
    also good for working on Iris and shutters. Some lamp bases and even pins on
    lamps will have a nickel coating on them. It's not wise to remove too much
    of it as it's there as a heat treatment.

    Once you have a smooth mirror like surface without any scratches from
    polishing visible (a small amount of pitting will be ok) you need to treat
    the surface of the lamp base or pins to make sure the freshly exposed metal does not oxidize. Some use normal de-oxidant and it works on lower than say
    1Kw lamps, Some sware by Craig De-Oxit, others advise a copper based
    De-oxidant, I use a McMaster Carr Electrical Contact Cleaner with Lubricant
    that while not rated for the temperatures has been shown to work well and
    without gumming up like normal de-oxidant will do on higher wattage lamps up
    to and including 5Kw lamps. If using a fixture with G-38 lamp bases (Mogul
    Bi-Post) and you have taken a lot of material off the lamp base contacts it
    might be necessary to use a thin copper foil wrap around the pin to make it
    slightly larger.

    When you lamp and test the fixture, you should not hear any sparking or
    arcing in the lamp base, and both pins should have equal grip on them. These
    tips will in general work for most P-28s (Medium Pre-Focus), E-26 (Medium
    Screw), P-40s & E-39 (Mogul of the two) , ferrule and R-7s (RSC) based lamp
    bases and lamps. RSC lamps especially need lots of attention. Get out an
    inspection mirror and flash light and have a good look at these pins when
    servicing the equipment because the design in general is not that great.
    Such a technique to inspect the wiring and bases of any fixture in general
    is a good idea to stop a problem before it becomes really bad. The earlier
    you fix problems, the more chance you won't have to replace them.
     
  11. ship

    ship Senior Team Emeritus Premium Member

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    Location:
    Illinois
    My own antique fixtures to work on. This in addition to stacks of 360, 360Q and 1KL Lekos that came out of some club that closed down and were found some years later in the back of a leaky storage trailer in not only bad but rusted condition:

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    My Chicago Lighting PC Leko X-Mass Present. It's missing everything inside and gong to need a lot of de-rusting.

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    The owner's Strand PC Lekos I'm storing but not sure what he want's me to do with.

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    A Bantam Superspot I had to install a lens and make a gel frame holder to. There was a couple of lenstrain and other configurations to this fixture including slide projector. I'm yet to find any literature or more than one more example of this type of fixture out there so far. Note the brass wires used for cooling fins. The rear side also has a large wound wire handle. Very decorative.

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    A Major Light's PC that was chopped down in length some time in the past to make it have a wider field angle - a common on-site improvement. Note the out of balance yoke.
     

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