Most Kliegl
Fresnel fixtures use the standard Medium
Prefocus (P-28s) based lamp with a 2.3/8"
LCL (between the
pre-focus fins and center of the
filament) as any other
Fresnel.
Halogen or
incandescent lamps don't matter - optically and to some extent, light wise it's the same lamp.
Incandescent lamps will have less in
color temperature but not too much less luminous output dependant upon the lamp of course. Just make sure you are not using 3.1/2"
LCL lamps in the fixtures - I’m not aware of any Fresnels that are using a 3.1/2"
LCL P-28s
base lamp. It will work if it fits but your beam will be way off in no longer being round. (One will note that I’m using the more modern metric or numeric
system for lamps and bases types - it is accurate like a
ANSI code for a lamp, and all should get used to it.) Once wired with new SF-2, 16ga
wire and possibly a either re-surfaced in the center contact plus cleaned up outer shell, or replacement lamp
base is installed, all should be fine in going with either
halogen/
incandescent, than lamping up to 750w. Be cautious about one lamp if still in use that I have seen. This lamp has a fairly small size and a clip bracket around the
globe itself. Normal lamp except it has a lengthened
base and a clipped bracket around the outside of the
globe. About that lengthened
base and clipped strap is a
asbestos padding. If you should see one of these lamps, put it into a zip lock bag and don’t use it.
That said, it might be Kliegl that early on was using a 2.3/8"
RSC (R-7s) lamp. Possible, does it look like it has a really short in length work light lamp
base in use for it? Many people
call such double ended lamps a "T-3" lamp? Otherwise the only other lamp that's possibly in use is a 400G/FL medium screw (E-29)
base lamp - a normal looking household but
porcelain light
bulb socket base to the
fixture. I have never seen a medium screw
base in a 6"
Fresnel but it's feasible to have either at one
point to have been installed or to have been a factory option.
For a
stage type - including from Kliegl 6"
Fresnel, these are the only lamp
base types I have ever seen or might expect so it should be fairly easy to determine which amongst three you have. I even own a
Fresnel fixture that used to have a above
RSC lamp in it - long since converted by way of using a
Altman lamp
base/
reflector assembly and just swapping the entire thing out. (This was produced during the days when
halogen lamps were first coming out and someone gave up the compact
filament shape for a
halogen lamp they could get. Imagine if one might, a
filament off a short work light lamp as your
Fresnel lamp
filament - this much less having the same lamp in use in a 3.1/2"
Leko I have also seen in use. Kind of like designing existing fixtures or new fixtures around a lamp in making it work by way of giving up efficiency. That’s some versions of Kliegl fixtures for you, but at least they use standardized parts and can be converted. You would easily notice if you have this
RSC type for your
Fresnel. If you have two single contact lamp bases which are horizontally mounted in the
reflector, you have this history piece. It's really easy to swap such a
fixture to a more modern type by way of new parts that will fit. Save one
fixture as it is and put it away as an antique, than upgrade the rest to
Altman 65Q parts in making them normal.
Beyond this, one can refine the type of
Fresnel in declaring if it has crank handles to adjust the focus or a more standard these days, a slide knob at the bottom of the
fixture. IF crank handle at the rear of thee
fixture, most likely it's using the standard P-28s lamp. Beyond this, one can refine if the crank handle below the
fixture is of female or male handle. Some older slide mechanisms had a 1/4-20 screw stud mounted to the lamp
base bracket and you used a knob. Otherwise it was a female weld
nut of the same screw size mounted on the lamp
base bracket with a male screw knob which is still in common for use now. Your
Fresnel will if it is under the
fixture slide screw type going to have a male or female screw type to it which will help define what type and age it is. After the ones with the male screw studs welded to the
base will be the ones with the female stud and a
socket head set screw driven into it. This will have a female
thru hole knurled knob that screws up and down on the screw.
In other words, as opposed to crank handle, if slide
base with knob at the bottom in this
fixture, you will either have a
bolt coming out of the bottom of the lamp
base that’s welded or not and just a
bolt, and it goes to a washer head
wing nut, or a female screw tapped hole or weld
nut on the bottom of your lamp
base bracket. This will either have a
wing screw or knob going into the hole, or have a hex drive
socket head cap screw and a
wing nut rotating on it that does the locking down. This is the major differences in type and age of
fixture.
Tips & techniques: (A week ago, I re-surfaced and re-wired like new 14 more old Fresnels making my re-wiring of 6" Fresnels done this year count so far about 40 in the last six months with lots more done in the past years. One might say it's kind of like a side project for me I have been doing about 15 years now in developing techniques, noting types - this is with all sorts of brands of
Fresnel.)
It's possible to re-surface your lamp bases if mechanically and electrically in good or ok condition. - Takes a Dremmel tool and various grades of grinding wheel going all the way down to a soft silcone reinforced fiber wheel to shine the brass up like new, than soft brass
wire wheels to work on the oxidation outer shell, but afterwards, even if you cannot and at some
point should not get rid of all the pitting, (dependant upon how bad it was) it will work like new. Once re-surfaced, coat all fresh contact surfaces
in one of various types of deoxident or I use "electrical contact cleaner with lubricant" and you are all set. Fresh brass without a coating will quickly oxidize and not work as well short of a coating.
[McMaster Carr #7437k15 "Electrical Contact Cleaner w. Lubericant 16oz. Spray" in being specific - good stuff thru 5,000 watts in coating fresh bright work on lamps and lamp bases. There is other types especially ones from the "Craig Deoxident" brand of coatings. If going deoxident, it needs to be a high temperature type over a copper based or other coating. The above “Electrical Contact Cleaner with Lubricant is not specifically high temperature but works well under testing. Spray a heavy coating than drip to dry before use.]
Once re-surfaced or lamp
base replaced, never use an old lamp that has not also been re-surfaced in the
base, unless you want to re-screw it up. Doesn’t matter how new, that pitting a lamp develops while lamp or
fixture base such arching to contact connection develops, it gets conveyed to what ever it touches new or old. Either new lamps or re-surfaced lamps and bases only and never new lamp
base in contact with old even if new/old lamps.
The lamp
base of the lamp itself can also be re-surfaced and coated in the same way by way of dremmel tool or abrasive fiber bench grinder wheel. If it survives re-surfacing, it should work fine electrically. If you take a
bit too much off, it will have had problems anyway and was not going to last long in lamp life. Trick is and dependant upon what brand of lamp, not to take too much off but to take enough pitting and or off shaped blobs of solder off so as to get a good contact. Lamps at their center contact are a
bit more fragile than lamp bases which normally have a fairly sizable center contact plate that can withstand some of it's
thickness removed and refined. The ones most often doubtful to safely re-surface are those that have a brass disc at it's center contact and a big off center blob of solder leading to it. take a little solder off and brighten up the brass and hope for the best.
Lamp
base types: GE and Bryant were most often used in the past from my observation. Once the arching is removed from the center contact, and that center contact is re-surfaced to a even if still somewhat pitted mirror finish, the brand of the lamp
base should normally become apparent. GE lamps (I believe they are older) look more grey than white and the lamp
base terminal screws do not come out - don’t attempt to remove them. The Bryant brand of lamp
base most often can be saved, the GE ones with a grey color to them often cannot but that’s 50/50% for me. Inspect the center contact, does it still spring, is it unscrewed, inspect the outer shell, are the screws holding it in place loose? Inspect and tighten contact plate to lamp
base screws and tighten as needed. On a refurbished lamp
base, check out all about it in tightening and ensuring it functions still and is not brittle to the
point of during these checks or removal it falls apart.
Give further attention to the contacts on your lamp
base or opposing side of the lamp
base. You can brighten up the brass some with the brass
wire wheel and probably should in getting a good contact again as long as you also re-coat it with contact cleaner and lubricant. Should be a plate that the wires connect to and it might move about some even after tightening as possible. Might or might not be one brass the other silver in color - just be sure when wiring that your hot goes to the center contact. A
bit of movement on the plate is ok, too much or if your screws break as you tighten, that’s bad. Have a look at the #4-40 lamp
base mount inserts at the bottom of the lamp
base. It’s wise to re-tap these in cleaning up the hole some for a fresh screw. Frequently if your insert is of a later type, the
porcelain will be breaking away from the lamp
base about this insert and depending upon how bad or loose, this will be a cause to replace the lamp
base.
Replace if not GE above, all your screws going to the lamp
base. Might be ok, but just replace them especially with lock washer based screws. I like #6-32 pan-head slotted screws of silicone/bronze that have external tooth lock washers already attached to them, though a brass screw with a silicone/bronze external tooth lock washer added would be fine. Lock washers are a good thing. Also replace the screws that hold lamp
base to the lamp
base bracket. Normally if not corroded solid in breaking, they are toast even still. I’m a big fan of #4-40x1/2" type 18-8 stainless steel
button head
socket hex screws with a added lock washer and high temperature
thread locker. No matter the drive type, stainless steel and of that size and type of metal is a good thing. Zinc plated screws in high temperature applicationus will often suffice but won’t for longitivity. In other words, your zinc plated steel screws - especially if smaller than 3/16"/#10 will rust in place within the light
fixture. Where possible, don’t use zinc plated steel screws even if they are better than un-coated steel screws in general.
For wiring to the lamp
base, use at least 600c temperature high temperature ring terminals - not the Ace Hardware type tinned ring terminals. Use a #6 stud/16-14ga
terminal that’s high temperature - it is that is it not? Over the
crimp/
barrel part of the
crimp terminal, you had best insulate it with fiberglass electrical tape or you will have shorting problems with time. 3M/Scotch #23 or #69 fiberglass electrical tape in ½" is good for insulating the
barrel of a
crimp terminal. Three wraps and it’s good to go in not conducting. Should you have a old GE lamp
base, make the
ring terminal into a fork
terminal by way of dikes. Cannot say how bad it would be to use normal
crimp terminals for such a high temperature application.
[I won’t get into proper crimp tools for crimping, but it’s assumed it has a tooth to it for displacement of material instead of smashing or crushing for tension.]
There must be an
insulator pad between the lamp
base, it’s
crimp terminal (or as in the past
wire wrapping sort of washer) and the metal of the lamp
base mount. Don’t re-use old
insulator pads. Most likely they are toast and brittle. That’s a
dielectric and in general insulating type of question beyond concept of upgrade verses something not so safe. Either use the new ones provided with new lamp bases or I’m a big fan of
ceramic fiber pads. Such pads are much like the
asbestos pads one might often find in use in older fixtures. Just a white fiber pad that’s between the lamp
base and metal. Look to McMaster Carr 87575k85 and 87575k88 for such
insulator pads. Not so certain about weather resistance and moisture resistance of such pads over time, but for now it’s what I normally use.
Onto new lamp bases. Be very careful about just swapping out lamp bases. The new
Leviton for instance, lamp
base is much larger in size than the old classic ones. By this I mean not that it won’t focus in the same position, instead that it’s OD is larger to the
porcelain. Often on a new lamp
base, especially if your lamp
base frame is aluminum, it’s going to be a really tight fit to fit the new era of lamp
base into that of the old frame. Some times the mounting holes while standard, also won’t align or the wiring exiting the lamp
base will get in the way.
Take the old lamp
base, draw it’s dia. and expand it to the new dia. than drill new holes to align that
base to the
reflector. This or do your best in keeping that alignment of lamp to
reflector center distance and alignment of
filament as parallel to the
reflector. Should be able to make it work, just check your alignment or you loose efficiency. Also should your wiring be a wee
bit closer to the bracket that holds the
reflector by way of wires coming out of the
base than one would like by way of rubbing, a good silicone coated fiberglass sleeving can sleeve the
wire feeding the lamp
base as another option anyway in coming out of the hottest part of the
fixture so as to ensure it don’t rub or get too hot and touch metal. Say a #9 sleeving over a SF-2
wire. Yet to have to other than use original mounting holes, but should one need to rotate the
base in making it work, just be careful in keeping that
filament to
reflector distance.
Your
ground screw need go to this lamp
base mount. That’s a basic concept. Next for
strain relief, I’m a big fan of the 3/8" NPT two screw strain reliefs
Altman sells for their fixtures as oppsed to using a Home Dept style ½" NPT two screw
strain relief that doesn’t
grip the cable as well and needs a larger hole. Still what ever
strain relief, choose one of a few holes and drill it out for the
strain relief. Add
thread locker and one now has once grounded and strain relieved a modern
Fresnel for all intensive purposes. This assuming SF-2 conductors and fiberglass sleeving over them and not some other method that’s dubious.
Amongst other things, clean, than polish the
reflector, put the
lens into a dish washer with lots of “Jet Dry”, and re-tap all holes and replace all with fresh bolts. You now have a new
fixture. Pay attention to paint chipping or peeling, that can be a problem.
Also be aware that some fixtures have lamp slide light
blocking plates between the lamp
base and bracket, and that slot at the bottom of the
fixture. Sometimes they become lost and there are at least two different sizes of them to be aware of. Otherwise if crank handle, take it apart, clean it up and either add some white lithium grease to it or Teflon lubricant to it. Good to go. Any self tapping sheet metal screws and other parts are also easily replaced.