Most UV bang for your buck?

[mimosatexas]

Stripping it down to just the bare essentials of a bulb outputting UV in the proper spectrum, what is the best bang for your buck?

Essentially, I'm looking for whatever weird chinese knockoff unbranded metal halide bulb would be the best "deal".

I don't care about an integrator, or shutter vs instant on, etc.  All I am looking for is the absolute most powerful light source for the lowest cost that can produce a consistent amount of UV in a specific time (unlike the sun).  Any ideas?

[sben763]

http://www.bulbamerica.com/ushio-mhl-1000-1-blacklight-metal-halide-bulb.html. This is what I am using. Has the correct spectrum for photopolymer. I took a old national exposure unit built a manual metal  shutter and a fan for the bulb.

[mimosatexas]

Thanks for the link. Finding 1k units for dirt cheap is pretty easy. I was hoping someone might have a source for 3k or 5k bulbs and ballasts.

[sben763]

I can find 3K and 5k bulbs.  Ushio has plenty but no one seems to have the ballast.  I have called several light supply companies.  I was wondering if they could be hooked in parallel. 

The biggest I have found is 1500w and 2000w. I would be interested if anyone has a source for a 3000w or 5000w ballast.

http://www.bulbamerica.com/ushio-mhl-261l-5000w-250v-photo-polymer-uv-curing-metal-halide-lamp.html

Here is a 5000w.

[IntegrityShirts]

I can find 3K and 5k bulbs.  Ushio has plenty but no one seems to have the ballast.  I have called several light supply companies.  I was wondering if they could be hooked in parallel. 

The biggest I have found is 1500w and 2000w. I would be interested if anyone has a source for a 3000w or 5000w ballast.

http://www.bulbamerica.com/ushio-mhl-261l-5000w-250v-photo-polymer-uv-curing-metal-halide-lamp.html

Here is a 5000w.

Olec is a good source of power for 5k bulbs
http://www.ebay.com/itm/Olec-Olite-AL-53-UV-light-Hood-power-Supply-/281295563060?pt=LH_DefaultDomain_0&hash=item417e85a934

[mimosatexas]

that bulb looks perfect.  I have been googling for ballasts without luck all morning.

[StuJohnston]

Out of curiosity, I checked the local electrical supplier for ballasts and the  highest they have is 1000W. I am pretty sure that ballasts over a kW like what we use are pretty specialized. I also took a look at Alibaba http://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=5kw+lamp+ballast

[IntegrityShirts]

that bulb looks perfect.  I have been googling for ballasts without luck all morning.

Olec al-53 is the power supply for that bulb,  with I think the 1260/1262 lamp headt.  You can find them used all over the place for under $500. They weigh about 150-200lbs though so shipping hurts.

[mimosatexas]

The problem I see with buying an AL53 is it is branded and sold as a screen printing exposure system, and is priced at a premium as a result.  New they run $4K and include a bunch of extras.  Replacement bulbs from Douthitt cost twice what comparable bulbs cost from other sources, though obviously the build quality may be different.

The used one you linked is being sold "as is" and has not been tested.  The cheapest one that is being sold as tested and functional is $700.  I guess I just can't understand why a new ballast and power supply for a 1000W can be had for under $100, but a 5000w is 40 times as expensive new or 7 times as expensive used.

[IntegrityShirts]

I think I bought my AL53 for about $400 shipped. The motorized shutter didn't work on it, hour or so of tracing with a multimeter on the main board found a little ice cub relay was dead. Easy fix.

I'm just suggesting that these 5kw olec units are plentiful in the used market, coupled with a used light integrator and you have a full on professional 5kw exposure/timer control for under $600-800.  Add a diy vacuum blanket/glass/frame and you're done.  Even if you find the 5kw ballast you'll have to manually operate a shutter and start a stopwatch or something with each exposure. That's exactly what I did with a 1000w grow lamp prior to upgrading to the olec. It was a pain in the butt haha. Now I have possibly the most ugly exposure unit in existence, but it works well.

[ScreenFoo]

IMHO, an AL-53 in good shape is worth at least ten times what a 1k warehouse light is worth, not only are you looking at the integrator and cell interface as well as the shutter, but they are very efficient in the spectrum you need.

FWIW, if a thousand sounds like a lot, they retail for five...

[Inkworks]

Thanks for the link. Finding 1k units for dirt cheap is pretty easy. I was hoping someone might have a source for 3k or 5k bulbs and ballasts.

Nuarc Flip-top plate makers, come with 3000 or 6000 watt instant start MH. with built in integrator, I've seen 3K go for a couple of hundred, and 6K go for under $500.

3K
http://www.ebay.com/itm/Nuarc-FT26V3UP-KM-Ultra-Plus-Flip-Top-Platemaker-/171283159511?pt=LH_DefaultDomain_0&hash=item27e14599d7

6K
http://www.ebay.com/itm/Nuarc-FT-40V6UP-2-sided-Platemaker-Burner-/271447341545?pt=LH_DefaultDomain_0&hash=item3f3385b9e9

Of course if you buy the 6K, you're better off just modifying the vacuum frame to accept a screen, It should fit a 23 x 31 without any trouble. I have a full write-up on here already.

[Inkworks]

ps: I've been using my 3K unit for 12 years with the same bulb, and the bulb was used when we got it, it still smokes my 8K Olec for exposure times due to the light being so close to the screens.

In fact it's exposure times were in line with the fastest times posted for the LED units, and I'm using Diazo emulsion with a med exposure time. (Autotype 8000)

[mimosatexas]

Nice finds!  I wish I was in Virginia

Nothing similar within Texas though based on my searching.

I am looking for just the light as I plan on using it for exposing huge frames for all over printing and sign printing among other things.  Some of the art is a good 4 feet across, so the light will be 6 feet away, and a 1k bulb takes a hell of a long time at that distance, plus the glass will be thicker than my other unit.

My 1k diy MH unit with vacuum top is working like a champ already (at least compared to the tube unit I built before) and I actually had to lower the light almost to the ground to make the exposure slow enough that I can comfortably washout a screen, squeegee it, check it for issues, set it on the dry rack, and walk back to the unit in time to pop the shutter.  It was exposing a little too fast at 1.5x the diagonal of my art.  I also removed the reflector to see if it cut down on undercutting due to spreading the light, replacing it with matte black instead.  So far it does seem to have helped.  I can hold every single dot on a 45 lpi film from my 1400, but I still feel like I am losing too much when I try 55 lpi.  Not sure what to do about that exactly.  Glass is 1/4", film is standard wp inkjet, 1400 is printing without a rip, but I have played with all the settings and it is basically putting down as much ink as the film will accept without it starting to blur and oversaturate.  full exposure to a hard 7 at 31" from the glass on a 2/1 coated 160 is just shy of 2 minutes.

Out of curiosity, what exactly makes a bulb instant on vs requiring a warmup time?  Is it the ballast, power supply, or the bulb itself or the combination?

[Inkworks]

Basically it doesn't have a shutter, it still has a short warm-up time, maybe taking 20 seconds to hit full brightness from dead-cold, subsequent exposures with a warm bulb means even less warm-up.

My 8K Olec is 4.5' away from the surface of the screens. going to 6' would probably double exposure times.

I'm not sure what the electronics or bulb differences are.

I buy used stuff from all over N.A. I'm in BC Canada, so I know shipping expenses all too well. You should be able to get that shipped for ~$300, maybe less, I have a great US freight broker if you need it. A 6K bulb, reflector, ballast, integrator, and vacuum pump for ~$500 landed is a heck of a deal i.m.o. My 8K light source was over $2000 used. My vacuum frame was a good deal though , traded $200 worth of printing for a 4' x 6' wall mount unit in good shape.