UV Printer Multiple-Bulb Fluorescent Ballast Choice
I'd like to build a UV printer to contact print cyanotype and Van Dyke brown up to 11x14, and would greatly appreciate some guidance on the electrical side of things.
I've read Carlo Ponzoni's "Building a UV Printer" article on alternativephotography.com , and Sandy King's "Ultravoilet Light Sources for Printing with the Alternative Processes" article on unblinkingeye.com. Having read these articles, I've decided that a fluorescent bulb UV printer will best meet my needs, and that I'd like to build a UV printer that uses a total of six 18" fluorescent T8 blacklight bulbs.
The GE F15T8/BL bulbs (Product Code 35884) seem like they'd work well.
I feel like it'd be cheaper and easier to install a single high-quality ballast that can handle six of these bulbs at once that to install three el-cheapo magnetic ballasts each driving two bulbs.
The GE GE632MAX-H90 ballast (Product Code 74117) looks like it'd be a good choice, as it's a high efficiency multivolt instant start electronic ballast.
The system specs show that it'll handle six F17T8 bulbs simultaneously, but the product page is silent on its ability to handle six F15T8/BL bulbs.
Does anyone know if the F15T8/BL bulbs will work in this assembly? These bulbs aren't listed as compatible, but I don't know whether this is because they're specialty bulbs that wouldn't be included in a normal compatibility list, or whether this is because if I attempt to use them I'll burn my house down. I'm (obviously) no electrician, but the difference between a F17T8 bulb and a F15T8 bulb seems minimal to me.
It depends on how fast you want the printer to be.
I built one with 9 BLB 13w integrally ballasted BLB compact flourescent light sources, able to handle a 11x14 contact frame, that prints cyanotypes in 30-60 minutes, for under $80.
I would stick with basic 2 tube ballasts, and not fret the potential for variation in output between three of them unless it proves to be a problem.
my real name, imagine that.
Here was GE's reply when I asked them directly:
So, it looks like I'll be installing multiple ballasts for the multiple T8 bulbs.
You apparently had a question for GE regarding the compatibility of our electronic GE632MAX-H90 ballast with F15T8/BL lamps. The answer is no...this is a preheat lamp and requires an equal type ballast. Best bet is Advance.
Mike: I read that CFL blacklights are made the same way as those old-school el-cheapo incandescent novelty blacklights, in that they're a cheap filter applied over a full-spectrum light. In contract, the blacklight fluorescent bulbs emit the desired wavelengths directly.
30-60 minutes is too slow for my needs. My normal cyanotype printing time (Mike Ware's new cyanotype recipe and Sacramento's summer sun) is 4 minutes ... I know that my time is going to increase, but a 60-minute time is too long!
incandescant produces very little to almost no UV. Flourescent of all sorts produces UV. Usually it is filtered out by a coating on the tubes. Any old plastic diffuser on a 2x4 troffer that has yellowed has done so from the UV produced by the bulbs. BLB just filters out the visible spectra. Dedicated T18 may be the better way to go, but I bought my compact tubes with Canadian Tire money.
CTM is a store script, that accrues from purchases in their store or gas bars, or when you use theier credit card, as a small fraction of all purchases. I typically accrue about $8 per month these days. I really piled it up when I had two kids in day care, and payed their fees with my Canadian Tire Mastercard credit card. That was when I bought the 10 tubes on sale at 50% off.
my real name, imagine that.
First of all, I have no experience with UV printers. But, I work with standard fluorescent lights quite a bit. The long-term reliability of magnetic ballasts seems to be much better than electronic ballasts. I realize that's a broad statement, but in general, our success with electronic ballasts has been poor. However, in your case, you probably won't be using the printer 8 hours a day five days a week for years, so reliability might not be a problem. Still, I have more faith in preheat magnetic ballasts than electronic.
Also, you have to watch the ballast factor. The higher the ballast factor, the brighter the tubes will be. Most ballasts should be around 1. Above 1 and the tubes are overdriven, under 1 and the tubes are underdriven. Overdriving the tubes will make them brighter but they won't last as long. Just something to keep in mind. If you are concerned about printing time, be wary of ballasts with a ballast factor of much less than 1.
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What sort of wattage would I need to get a good contact print UV setup going?
I built a UV printer myself, a while ago. I am not sure the specific GE F15T8 bulb is what you are looking. It would certainly expose but the speed is crucial. I cannot seem to find its specifications about the wave length it produces. If you can confirm that the bulbs produce peak output around 350- 370nm then they would be a good choice. BL is blacklight but It would be better if you can confirm its specifications.
An old thread on the subject I asked about the bulb, http://www.apug.org/forums/forum42/9...rinting-2.html
I used sylvania brand F24T? (8 or 12 I can't confirm now) BL368 bulbs 20W each ten in total. BL368 / BL350 / BL365 are the codes of the bulbs with suitable wave lengths.
From my experience, it is going to be a cable mess, I used 5 dual ballasts to power box. If you are going to use a single ballast, wrong connection means no power to all.
If you use more than one ballast, you can troubleshoot easily if there is a problem with ballasts or bulbs. I would prefer 5 ballasts over 1 ballast system.
Don't worry, you can't burn the house down.
I expose traditional Cyanotype for 7-8 mins, New Cyanotype 7 min, VBD 4:30, Salt 10-12 mins.
edit : double attachments, sorry
Last edited by Herzeleid; 11-29-2012 at 04:41 PM. Click to view previous post history.
Wow that looks like you have put the sun in a box lol so I will need about 200W of UV? How does it compare to exposing in direct sun?
You don't need 200W exactly. I placed 10 bulbs in order to increase the exposure area. (It was quite unnecessary btw). The final W will depend on the exposure area you decide. If you decide 6 bulbs, 2-3cm wide each placed with 2-3cm space between each bulb you might have an area of roughly 40x60cm. Big enough to accommodate A3 size paper. That unit will use 120W ( 6x20W ).
Originally Posted by m1tch
You can place bulbs higher, and therefore you can have a larger area to illuminate but then the exposure times would increase.
I have never effectively used the sun for exposure. I tried some cyanotype at cloudy days 1-2 hours of exposure yielded only a faint image, which eventually washed away.
Hmm im planning to use it on Cyanotypes, I live in the UK so its not always sunny lol also I might want to do some contact printing after work in the evening, none of the prints will be bigger than A4 as I don't have a negative that big!
I have seen some tunnel type UV lamps mainly used for nails and they are 36W for a fairly small area, im tempted to perhaps try one of those at some point as they are pretty cheap and i'm not planning massive prints at the moment as im just getting into alt methods.