Screw-in UV bulbs...verdict?

[CraigK]

I will be building yet another UV box in the next few weeks and am considering using screw-in UV bulbs. Of course, I could go the tried and true route of fluorescent tubes and ballasts as well.

So, any verdict yet on the price/speed/effectiveness of the screw-in types yet? I know that there are a couple of folks on the board that are using them.

What say you?

 

[Donald Qualls]

The spiral CF in BL or BL-B are pretty pricey, from what I've seen, with low output relative to the larger sizes of tubular fluorescent. Much simpler to build the unit, but you'll probably wind up spending about the same unless the bulb shape lets you use a much smaller unit and fewer bulbs. I've been thinking about using an array of 6 to give an 8x12 inch printing area, but that'd still be something like $100 to build the unit (counting lumber, sheet metal, wire, and sockets).

 

[CraigK]

Ya, I can't see saving any $$ by going with spirals but I may save in the weight dept.

I would like the unit for use at my school where we may need to move it from time to time. The standard tube units that we have seem to weigh about as much as a small car.

Anyone know of any Canadian sources for the spirals?

 

[sanking]

Just curious where you saw spiral BL tubes for sale? So far I have only seen BBB.

Sandy

The spiral CF in BL or BL-B are pretty pricey, from what I've seen, with low output relative to the larger sizes of tubular fluorescent. Much simpler to build the unit, but you'll probably wind up spending about the same unless the bulb shape lets you use a much smaller unit and fewer bulbs. I've been thinking about using an array of 6 to give an 8x12 inch printing area, but that'd still be something like $100 to build the unit (counting lumber, sheet metal, wire, and sockets).

 

[Shinnya]

But if you include prices of ballasts, isn't it more expensive to go with tubes?

Like when I build tube type, it was like $7 for tube and $20 for a ballast for 24". Well, I guess I should do some calculation first.

Warmly,
Tsuyoshi

Ya, I can't see saving any $$ by going with spirals but I may save in the weight dept.

I would like the unit for use at my school where we may need to move it from time to time. The standard tube units that we have seem to weigh about as much as a small car.

Anyone know of any Canadian sources for the spirals?

 

[Phillip P. Dimor]

I thought that most of the cost was in the ballasts themselves. Perhaps you'd save money if you were building a smaller (10x12/8x11, etc) printer as opposed to a giant bank of spiral bl bulbs.. I'm thinking of building one, myself and using the spiral bulbs.
I only really print 4x5's at the moment so I wouldn't need a 16x20 or 20x24 monster printer.


http://www.bulbman.com/index.php?main_page=product_bulb_info&cPath=4351_8839&products_id=13846
has 27w BLB for $12.50.

http://www.saveonlighting.com/itemdetail.asp?item=1091
Item #: SL20/BLB-BX, Catalog #: 05439
is a 20w BLB for $11.49.

Does anyone have any experience or tips? I am interested in this as well (and sorry if i've hijacked a thread)

 

[Monophoto]

Like Phillip, I am also thinking about building a UV box. In fact, I have a "design" sketched out and starting picking up materials last week.

Linus is a ULF & Pt/Pd printer who posted in another thread a couple of months back that he uses the 20w. spirals in his UV box. I saw some of his work at the LF conference last year and it was gorgeous. I suspect that there was more involved in achieving that look than just his choice of bulbs.

In my case, I am thinking about a box that will allow me to print up to 10x15". It will have six bulbs on 5" centers. I'm thinking about using the spiral bulbs because my experience is that spiral CFL bulbs, with their integrated electronic ballasts, tend to give better starting performance than inexpensive tublular fluorescents with magnetic ballasts. My initial run at a cost estimate is that a box using spirals will run about the same as a box using cheap tubular fixtures - to get the better electronic ballasts with tubular fixtures will cause that option to be much more expensive than a design based on spirals.

One other thought - with tubular fixtures, the recommendation is to line the top of the box with a sheet of metal. This supposedly helps assure that all of the tubes start when you turn it on, and it also provides a reflective surface. I don't think that the metal sheet is required with spirals, but I'm still planning to use it for its reflective value.

 

[Allen Friday]

When I built my 48" light box, I used pre-assembled shop lights--they are the metal lights one hangs above a work bench that plug directly into the wall socket. I priced buying all the parts seperately, and found shop lights cheaper. I got mine at Home Depot. They were around $16 each (sorry I don't remember the exact price). There are expensive ones, and there are cheap ones. I got the cheap ones. But they still have the electronic balasts. One big benefit, no additional wiring. I pluged the units into an outlet strip, which goes into the timer.

Allen

 

[Bruce Schultz]

So with bulbs on 5-inch centers, you'd have 3 bulbs across and 5 bulbs down? Would you position the sockets so the top of the bulbs are pointed down, or situate them horizontally?

 

[Monophoto]

So with bulbs on 5-inch centers, you'd have 3 bulbs across and 5 bulbs down? Would you position the sockets so the top of the bulbs are pointed down, or situate them horizontally?

Actually, my 10x15" box will have a 2x3 bulb array on 5" centers.

I am currently planning on a base up (spiral down) - that's what everyone seems to use. But when I look at the bulb, there is clearly more light-emitting area on the side than on the top of the bulp, and it does seem to me that a configuration with horizontal bulbs might be more efficient. Actually, I started a thread on that subject a couple of weeks ago, but either no one understood the question, or else everyone wanted to talk about something else.

 

[avandesande]

Thats easy enough to test, try two bulbs next to each other on your alternative substrate, one pointed down and one sideways. This would also give you a good idea of how much coverage to expect.

 

[TheFlyingCamera]

I suspect why nobody does the sideways bulb configuration is the amount of real estate you'd lose to the socket configuration. You'd be far more likely to get banding in your prints from the wall you'd have to make to mount the sockets on. The reduced light level from having the bulbs a bit more spread out would be a far easier price to pay (slightly longer exposure times) than having banding in your prints from obstructed lightpaths.

 

[Monophoto]

Fly -

That's a valid concern if you design the box so that the sockets are bottom-to-bottom on a strip down the middle. But what about the case where the size of your box requires only two rows of lamps. In that case, you could mount the lamps with their bases on the outside. I would think that would avoid the banding problem.

The basis for my question about horizontal mounting was the thought that this could be a more efficient arrangement if more light is emitted from the sides of the spiral than from the top. On the other hand, in the horizontal design, only one side actually faces the contact frame. So perhaps the answer comes back to maximizing the UV reflectivity of the inside of the box in order to take advantage of as much as possible of the emitted light. That's why I'm planning to line the inside of the box with sheet metal (actually, aluminum flashing).

 

[Donald Qualls]

Just curious where you saw spiral BL tubes for sale? So far I have only seen BBB.

Don't know that I have seen BL spirals, as opposed to BL-B. Straight tubes come in both, but my brain was sufficiently overloaded trying to keep track of prices and such when I was looking at them that I might well have thought I'd seen something I didn't.

In any case, what I've been thinking about is *2* of the BL-B spirals (about $25 plus shipping for a pair) mounted in a pair of $7 reflector clamp lights, which would be stapled in place on a board or similar mount to give them a fixed location. I think two such lamps would let me get even enough light to print 8x10, and I don't have other equipment to support even that size yet -- a single would probably work for 5x7 and smaller.

First, however, I plan to try Cyanotype Rex, which I've heard is fast enough to allow in-camera negatives and paper-to-paper contact prints -- which implies it might also be usable for actual enlargements under a cold light head...

 

[sanking]

Just for the record, somebody posted a message ( not sure if on another thread on apug.org. or elsewhere) that the spiral BLB tubes can not be used in horizontal orientation due to the nature of the ballast. I have no idea if this is true, but I know for a fact that it was said, and the poster did seem pretty confident of the information.

Sandy

Fly -

That's a valid concern if you design the box so that the sockets are bottom-to-bottom on a strip down the middle. But what about the case where the size of your box requires only two rows of lamps. In that case, you could mount the lamps with their bases on the outside. I would think that would avoid the banding problem.

The basis for my question about horizontal mounting was the thought that this could be a more efficient arrangement if more light is emitted from the sides of the spiral than from the top. On the other hand, in the horizontal design, only one side actually faces the contact frame. So perhaps the answer comes back to maximizing the UV reflectivity of the inside of the box in order to take advantage of as much as possible of the emitted light. That's why I'm planning to line the inside of the box with sheet metal (actually, aluminum flashing).

 

[Jordan]

In any case, what I've been thinking about is *2* of the BL-B spirals (about $25 plus shipping for a pair) mounted in a pair of $7 reflector clamp lights, which would be stapled in place on a board or similar mount to give them a fixed location. I think two such lamps would let me get even enough light to print 8x10, and I don't have other equipment to support even that size yet -- a single would probably work for 5x7 and smaller.

For what it's worth, after a suggestion from Sandy King, I've been using a single spiral BLB (Feit Electric -- I bought mine from topbulb.com) in a reflector clamp light to make my Van Dyke Brown prints (6x9"). It works well -- exposure time is about 8 minutes with my digital negs, at a distance of something like 40-50 cm.

 

[sanking]

Thanks for the report. Sounds like you have found a very inexpensive and efficient exposing system for your UV printing.

Does not take much to figure that if you ganged up a number of those tubes you could make big prints with a very small investment in the light source.

Best,

Sandy

For what it's worth, after a suggestion from Sandy King, I've been using a single spiral BLB (Feit Electric -- I bought mine from topbulb.com) in a reflector clamp light to make my Van Dyke Brown prints (6x9"). It works well -- exposure time is about 8 minutes with my digital negs, at a distance of something like 40-50 cm.

 

[Monophoto]

Just for the record, somebody posted a message ( not sure if on another thread on apug.org. or elsewhere) that the spiral BLB tubes can not be used in horizontal orientation due to the nature of the ballast. I have no idea if this is true, but I know for a fact that it was said, and the posted seemedm pretty sure of the information.

Sandy

0

Sandy -

When I first raised the question (another thread, perhaps another board), I mentioned that when CFLs were first introduced, the manufacturer's did impose constraints on mounting - the choices were base up or base down.

I just did some research in the other thread and found the following note from Nick Zentana:

"I'm not sure all those issues you mention have been cured. When I was looking at using them for an enlarger head I found a few things.

1) The bulbs over a certain size don't like being enclosed. Heat becomes a issue. I think 28watts. That's one bulb. If you're using multiple bulbs I bet you need to worry about cooling even if the bulb is rated for enclosed fixtures.

2) The bigger bulbs can only be burned bulb up."

Perhaps this is what you were recalling.

A logical followup question is "what is a bigger bulb?" I've seen some very large CFLs (equivalent to upwards of 300w of incandescent), But I've only seen smaller (eg, 20 and 27 watt) spiral BLBs listed on various web sites - are there any restrictions on these spiral BLB bulbs?

 

[Jordan]

Absolutely, Sandy. My next challenge is actually coating the VDB sensitizer evenly on the paper (my coating rod technique needs major work -- I get "stains" or uneven coating). It would have been even better if I could have found the bulb locally, but I couldn't find a Canadian supplier of the spiral BLBs.

 

[sanking]

My advice would be to junk the coating rod and get the Richesoin 9010, called by many the "Magic Brush". It makes coating a snap. The Richeson is not cheap but it is a good investment in your printing technique.

Sandy

Absolutely, Sandy. My next challenge is actually coating the VDB sensitizer evenly on the paper (my coating rod technique needs major work -- I get "stains" or uneven coating). It would have been even better if I could have found the bulb locally, but I couldn't find a Canadian supplier of the spiral BLBs.

 

[Donald Qualls]

Just for the record, somebody posted a message ( not sure if on another thread on apug.org. or elsewhere) that the spiral BLB tubes can not be used in horizontal orientation due to the nature of the ballast. I have no idea if this is true, but I know for a fact that it was said, and the poster did seem pretty confident of the information.

Can't say for certain that BLB spirals are the same hardware, just with different phosophor/filter coating, but I have compact fluorescent bulbs in my kitchen fixture (got tired of changing the tungsten bulbs every 3-4 weeks). That fixture mounts the lamps horizontally, and though they do work well enough in that orientation, they're very dim when they first start; I have no way to be sure if that's due to orientation or temperature, however.

Given that VDB is working with a single spiral BLB in a reflector, I'll have to get another reflector (beyond the one that holds my 1950s vintage safelight bulb) and order in a BLB CFL. Then I can start working on cyanotypes and such without being dependent on sunshine (or working in the day, for that matter).

 

[Monophoto]

Can't say for certain that BLB spirals are the same hardware, just with different phosophor/filter coating, but I have compact fluorescent bulbs in my kitchen fixture (got tired of changing the tungsten bulbs every 3-4 weeks). That fixture mounts the lamps horizontally, and though they do work well enough in that orientation, they're very dim when they first start; I have no way to be sure if that's due to orientation or temperature, however.

CLF's are notorious for their annoying "warm-up" characteristic. In some instances, it takes a minute or more for a CLF to reach full light output.

Most folks who use spiral BLBs for printing simply preheat the bulbs for a minute before starting the exposure. Since exposures in alternative processes are typicaly minutes, a little non-linearity is not normally a problem.

FWIW, I've studied the application of CFLs in our home pretty carefully. The basic economic analysis leads me to conclude that applications that are "on" for more than about 45 minutes per day will recover the higher cost of the CFL with the energy savings within the first year, so I've replaced every incandescent bulb that gets lots of usage. My next round of replacements will be where its a PITA to replace the bulb - have to get out a ladder, remove a cover, etc. I will not replace the bulbs where there is a need for the lamp to provide full output immediately (ie, the bathroom - when you stumble in there in the middle of the night, you need light NOW!), nor will I replace bulbs outdoors - CFLs don't start well when the ambient temperature is very cold.

 

[sanking]

You are absolutely right about this. I have tested the output of the spiral BLB tubes with an integrator and it takes at least 45 seconds from start-up to full output. But no problem, just turn them on and allow them to warm up for a minute or so and you are ready to go.

I do recommend some precaution in where you place the lights. Using them in a reflector suggests that they will be at or above eye level so you should take steps to cover or enclose the bulbs when exposing. Or wear UV googles.


Sandy

CLF's are notorious for their annoying "warm-up" characteristic. In some instances, it takes a minute or more for a CLF to reach full light output.

 

[Donald Qualls]

I will not replace the bulbs where there is a need for the lamp to provide full output immediately (ie, the bathroom - when you stumble in there in the middle of the night, you need light NOW!), nor will I replace bulbs outdoors - CFLs don't start well when the ambient temperature is very cold.

If I'm stumbling into the bathroom in the dead of night, and it's dark, and my eyes are fully adapted, the dim, weak startup from a CFL is likely to be a) plenty of light, and b) more than my eyes really want anyway. About 2 white LEDs would be just right for that situation. The place I won't (based on experience) put CFLs is where they need to operate in very cold ambient temperatures. I used to have one in a back porch light, and when it was below freezing out, I might as well have had a candle in a Chinese paper lantern.

So, even though it's a major pain in the arse to replace the bulb in my carport light (disassemble the fixture, while standing on a ladder I don't own), it won't get a CFL, because when I want it, I want actual light, not a dim ghost of luminance...

My plan for a CF-BLB in a reflector is to put it as low as will evenly cover my prints, in order to give the shortest exposures. I figure for 8x10 that will probably be below eye level with the prints on the bathroom, er, darkroom counter. This whole plan might get sidetracked, however, if Cyanotype Rex turns out to be as easy as it's looking; that process is fast enough and UV-independent enough I might be able to expose it under my enlarger -- even to the point of enlarging onto it! If that goes, I won't need a UV light source any time real soon...