Most UV bang for your buck?

[ABuffington]

The Histogram of a bulb says it all.  If you don't know the histogram for any bulb you are accepting a salesman's pitch, if he doesn't have a histogram of the lamp he either doesn't know what works, or he is hiding the following.  There is no cheap way to make a metal halide bulb.  The Original Equipment will have a far better histogram showing the UV output spectrum and the amplitude in between.  Cheap metal halides skimp on the expensive precious metals used in the lamp.  These precious metals are what makes the UV spectrum.  The cheaper the bulb, the less precious metals are used, or sometimes not as many are used to get the price down.  Bulb life is generally shorter. Wattage is important, so is the histogram of the bulb you are buying.  An  8k Olec with an L-1282 bulb has one of the best histograms going.  This bulb will expose both diazo and pure photopolymers completely since they like different wavelength spikes to expose well.  There is much more than meets the eye in exposure lamp construction than just ballasts and any old UV lamp, even if they are high wattage.  I personally would use OEM bulbs for longer life with stronger histograms of UV output. 

[mimosatexas]

I agree with the concept of getting the best equipment when you are trying to optimize your processes. 

I honestly don't care about that for this particular application.  I don't do a ton of oversized stuff, but enough to make getting a more powerful lamp worth it if the cost is $500 or so.  I know literally nothing about the 1k MH I use everyday, except that I got it from Homer and he said it worked and was extremely generous about it.  That said, it works fine and I haven't seen a need to optimize that part of my process again...yet.

It looks like finding a fliptop platemaker is the way to go, and if it has broken components that aren't related to the lightsource itself, all the better deal-wise.  I still find it hard to believe you can't source just a ballast/powersupply by itself from some random cheapo manufacturer.

[IntegrityShirts]

Along the same lines of most bang for the buck UV. Has anyone seriously thought about a DIY LED exposure unit? You can get LEDs in the 365-395nm range pretty darn cheaply in lower wattages. Higher power ones are more expensive but still not too bad. Won't really help you mimosa for large format exposure, but could be a cool test/retrofit for people with tube units.

[tonypep]

BTW I believe the term is Jerry-Rigged although so many use Jury Rigged by now they are synonomous.
Filed under who cares.

[Frog]

BTW I believe the term is Jerry-Rigged although so many use Jury Rigged by now they are synonomous.
Filed under who cares.

You sir, are obviously not a 250 year old sailor!
Most word freaks have found that "jerry-rigged", though popular, is actually the bastard child of "jury-rigged" (dating back to sailors making makeshift repairs in the late 1700's) and   "jerry-built", commonly understood to mean to be made cheaply or shoddy, and only traced to 1868. Interestingly, "jerry-rigged" according to some, can only be traced back to 1959.

For our purposes here, we welcome both meanings, and the board name has been modified to reflect this.

[sben763]

Along the same lines of most bang for the buck UV. Has anyone seriously thought about a DIY LED exposure unit? You can get LEDs in the 365-395nm range pretty darn cheaply in lower wattages. Higher power ones are more expensive but still not too bad. Won't really help you mimosa for large format exposure, but could be a cool test/retrofit for people with tube units.

Not only thought about I have done it. It requires a bunch of LEDs. You can get 1-3watt LEDs in the correct spectrum from many places but I choose to buy directly from china. I didn't use enough LEDs so my results were very similar to a florescent blacklight exposure unit.  I gave the entire setup to another guy who is still currently using them.   

I have a supplier suppose to call me back about 3000-5000 watt ballast.

[IntegrityShirts]

Along the same lines of most bang for the buck UV. Has anyone seriously thought about a DIY LED exposure unit? You can get LEDs in the 365-395nm range pretty darn cheaply in lower wattages. Higher power ones are more expensive but still not too bad. Won't really help you mimosa for large format exposure, but could be a cool test/retrofit for people with tube units.

Not only thought about I have done it. It requires a bunch of LEDs. You can get 1-3watt LEDs in the correct spectrum from many places but I choose to buy directly from china. I didn't use enough LEDs so my results were very similar to a florescent blacklight exposure unit.  I gave the entire setup to another guy who is still currently using them.   

I have a supplier suppose to call me back about 3000-5000 watt ballast.

Cool! How many was not enough, exactly? I might just tackle this as a project.  Would you suggest covering the whole under glass area with leds? What about distance from LED to glass? Maybe I should start a new thread. 

[ZooCity]

A used AL-53 setup is probably the most bang for the buck.  There are still units out there that were originally in service as plate makers (all computer to plate now) and for photography.  We have two complete units and, including parts/repairs, total cost is probably barely $1k over the 6 years or so we've ran them.  Integrators can be tougher to find sometimes but you'll see 'em on ebay if patient.

Alan is on the money with bulb quality for halides.  However, don't make the mistake I did last year and scoop up an OEM Olec bulb on ebay for cheap, they appear to have a shelf life and that "deal" I got on an Olec lamp was a waste of a hundred fifty bucks or whatever I paid.  Our knockoff from Caprock, though probably inferior in the heavy metals, was fresh and performed much better than the stale Olec from ebay.  The Caprock bulbs have actually done well for us.  At the same time, you're looking at maybe 1-3 bulbs/year for a shop, depending of course so that's not much more to invest for the spectral quality of an Olec bulb over the course of a year.

[ABuffington]

While LED is becoming more and more popular I think we need to step back and look at the physics involved here.  The Histogram, or the amplitude of specific wavelengths, (notice wavelengths is plural here) is what creates the exposure.  Specifically from 350/380 nanometers to 420 as well as the area in between these spikes and to the left and right of the spikes.  A histogram is the only way of knowing if your lamp will expose a screen well.  I can image with a 60 watt incandescent bulb if I leave it on the screen overnight, but did I expose the emulsion or just image the emulsion?  Exposure and image are two very different things.  Just shooting for an image does not mean it will be durable on press, especially with water base and discharge and HSA inks.  The key is to cross link as much of the sensitizer with the emulsion components using as much light as possible with the strongest multi-spectral light.  It takes energy, lots of it, in specific wavelengths to really expose the emulsion.  Look at it like gas engines.  A lawn mower is a gas engine, as is a 4/cylinder engine, as is an 8 cylinder engine.  Don't expect a lawn mower engine to do the work of a V8.  If you have an automatic and print either water base, discharge, or HSA and your run lengths are decent, you will get non stop production from a strong high wattage lamp with a fresh multi-sprectral bulb.  Yes you can use images on plastisol, but pinholes, loss of halftones and wear through can all be fixed with strong multi spectral light.  LED's are uni spectral mostly, with some multi-spectral units out there.  Note the lamps have chaotic light (undercuts fine details, especially ink jet films with low d-max) and they are the equivalent by inverse square law about the strength of a 1000 watt at 42 inches with a weak histogram of mostly one spike in one wavelength. There is a place for them in short run plastisol and with hardening short run wb or discharge.  But if I was running a multi auto shop I want bullet proof screens, non stop production, cause I know that's the only way I can compete price wise with the competition.  Drop 50-60 units per hour due to stencil breakdown fix its and the profit margin really takes a hit.  After all if you are an owner of the shop, you only get paid on what's left over and to maximize that profit I have found strong screens yield a better paycheck.  For DIY its all about not emptying the bank for something you can make yourself.   We used the sun when we had 4 autos before getting an 8k olec, the sun is not a consistent light source, and only good for 4-5 hours a day, but talk about a cheap exposure unit!  Last time I had the guts to put my light meter out there it was at 23,000 watts at noon and I had to pull the meter out of the sun for fear of damaging the sensor.  If you are in the north, get a good exposure unit, in the south the sun is super strong in summer.