UV curing light 220V 50Hz on 240V 60hz

[g1]

Hopefully I'm in the right place. A builder friend asked me about a UV light for polyester curing?
He was wondering about wiring up an outlet for 240V which is no big deal.
But I don't know anything about these lights and have a few concerns.
It's a mercury light as seen here:
Portable UV Light Curing Machine 1kW 220V Brand New Lamp | eBay

It's supposed to be for 220V 50Hz, here we are closer to 250V at 60Hz. Is the voltage or frequency going to be a big problem?

[Leo_Gnardo]

Taylor guitar has been using UV curing for their urethane guitar finishes, must be 20 years now. They say the finish sets in 30 seconds, and emits carbon dioxide & water, no dangerous chemicals. Polyester, I dunno. You could email Taylor, what's the worst that could happen, nothing? Give 'em a go.

[Shadrock2]

Don't know precisely what type of light. But a 1kW Hg light will emit substantial short wave UV radiation. This is the type normally filtered out by the atmosphere. There are three basic hazards. Most importantly is the eye protection. Make sure you have UV absorbing goggles. A 1kW light can cook your eyes real quick. Next is skin protection. While not as sensitive as your eyes you can definitely get sunburned + long term cancer risk. Finally ventilation because short wave UV produces Ozone.
The Hg lights can be broadly classed as low pressure (think florescent light without the phosphorescent coating), medium pressure, and high pressure. The medium and high pressure types are for higher watt types. As far as the power supply they usually have a high voltage pulse to strike the arc and regulation to limit current for normal running.

[tedmich]

There are really cheap Hg vapor lamps on ebay, they are commonly used in water sterilizers. They are pretty tolerant of the electricity they use but some ballasts may only handle a very specific voltage in some units. Generally all ballasts are now universal SMPS but there might be some old magnetic based ones that are finicky. Smaller UV light I've used are LED based and are used a lot in dentistry, but many of the very intense "spot" UV systems illuminate too small an area for many industrial uses.

UV is very bad for eyes, a bit less so for skin. I worked in a lab that had big banks of UV to sterilize an area where we worked on viruses; they ran all night with big warning signs on the door, but later we found out the janitors had gone right in likely getting cataracts earlier than they should.

[David King]

There's an article on line describing the system that Taylor uses that should answer most of your questions. In the meanwhile here's a section about finishing from the youtube channel
https://www.youtube.com/watch?v=6wyO...eature=related
The same ebay seller has that same wand for as little as $345. I would definitely ASK THEM if the units can handle the 240V @60Hz. It comes with a 1 year warrantee so it would behoove them to know the answer. It looks like an exact knock off of a USA made system that costs around $2400 so it's a "deal" but there's no telling what the actual output will be over time etc.
Different UV finishes require different wavelengths and intensities to cure fully. Basically the cure time is an exponential function of the W/CM^2. With 1/2 the power your finish will take 4 times longer to cure. The LED curing lights that dentists use are a totally different wavelength and are several orders of magnitude less powerful then the Hg lights, they simply won't cure the polyester guitar finishes.
Another option today is Solarez which will cure in bright sunlight near the equator but is probably not going to help you north of the 45th parallel unless you have a curing light like this one.
These finishes still stink to high heaven being styrene based and you need a supplied air hood + a spray booth to deal with them safely, figure another $3-4k plus $600-$1200 for a 4 stage HVLP compressor and spray gun.
UV pore filling is an unmitigated disaster so don't go there unless you use a cobalt-MEKP hardener as well.
The UV proof suit, hood and glasses are the cheapest part of the setup but they are indispensable.

[salvarsan]

Other UV safety notes: UV generates Ozone, yup, and in water it has a half life of 15 minutes. Reasonable 60-70% Humidity helps control it. Not sure how dry you need your spray rooms.

[g1]

Thanks for all the comments. I've advised him of the safety issues and suggested he ask the seller about the warranty for use on our power grid.
I'm assuming whatever the bulb runs on is regulated by the supply unit, so there shouldn't be any wavelength or bulb life issues.

[tedmich]

I always favor face shields with strong UV sources, ANSI Z87.1 U6 (or U5) certifications are good places to start.

If its unclear if a shield offers UV protection, have a piece of dayglo plastic (or a modern piece of US currency) and see if it fluoresces through the plastic when held in UV.

[Stevenson]

You need the ozone to overcome oxygen inhibition in polyester finishes in order to get proper surface cure. This is the reason Hg lamps are used. Other UV lights like the LED type produce too narrow a wavelength and the surface will remain tacky.

[g1]

Sorry I forgot to update the thread. He was told by the seller that it would be fine on north american line voltage.
He has wired it up and says it works great.

[David King]

G1,
Thanks for dropping back in with that info. At that price it might be very tempting to quite a number of builders i know.
I was sent a sample a few years back of a corn based UV resin from Canada that was designed as a low VOC way to seal concrete floors in huge warehouses. The resin is water clear and super hard but I could never get it to cure completely with just sunlight or the halogen bulb that came with it. It's main benefit was that you could brush it on indoors with no protection and cure it with a more or less standard lightbulb or in sunlight. With a good UV source it really would be a decent product.