UV lens for MH lighting?

Hi,

I am considering buying a MH retro kit and would like to know if any body has any links where I could find a UV lens for the MH kit? Any links to MH deals would be good also. I am looking to add a single 100 or 150 watt MH with the daul 32 watt PC lights which I curently own.

Fuentes925

You don't need any special lens, which is why nobody sells them. The only thing you see sold as "lens" is just a piece of glass which has been cut to fit whatever hood they're selling.

Just go to any glass shop and have the appropriate piece of borosilicate glass cut for your hood. Borosilicate glass can take the heat, and harmful UV will be blocked.

This should cost less than $10-20 for the glass (depending on how large a piece you need), and a couple bucks for the cutting fee.

By the way, "standard" MH bulbs (the type that screw into the socket) are already encased in a UV-blocking sleeve, so you only need a lens as a splash-guard, if you want it at all.

However, compact double-ended "HQI" bulbs are not encapsulated, so you must add another layer of glass to block UV.

Thanks for the info, you have been very helpfull.

Fuentes925

That was one of the more helpful posts I've seen on the subjec. Short clear and visual aids. Nice.

If you are looking for acrylic that filters out UV, it is OP-3 acrylic. That's the stuff they use for pictures and paintings so the UV doesnt fade it.

I wouldn't suggest using acrylic because it tends to deform/warp from the heat of the MH. I know from experiance

Originally posted by MrConclusion

Just go to any glass shop and have the appropriate piece of borosilicate glass cut for your hood.  Borosilicate glass can take the heat, and harmful UV will be blocked.

 

This should cost less than $10-20 for the glass (depending on how large a piece you need), and a couple bucks for the cutting fee.

Just to underscore the point about heat...

I'm not sure what borosilicate glass is BUT I will also suggest tempered glass as an alternative (if you are using the DE bulbs). When I recently had to replace the glass for my MH pendant I ended up cracking two pieces of glass before I realized that the regular glass could not take the heat generated by the bulb. In my case, a piece of 3"x22" 3/8" tempered glass set me back around $35.

HTH

I believe borosilicate glass is like pyrex so it could take the heat

Ive always been curious about this so I will ask here. Do we know for sure that DE bulbs are not filtering out UV?

I mean, when I look at the posted picture I see SE bulbs that are identical to DE bulbs as far as internals go. The only difference, is a bigger glass casing that they are in. I know for sure, it is not a different type of glass.

Does anyone know what the real deal is?

I thought the double ended bulbs have a quartz outer casing, whereas the single ended is plain glass. The quartz (I assume) doesn't block UV.

Just go by what the manufacturer tells you. If they say that you need a shield, get a shield. Its not worth damaging your eyes.

I noticed that my shield was not on all the way, leaving a crack. The acro under this area was bleaching. And I've been having eye problems - but this may be due to my constant computer use lately

I've read that UV damage to the retina can cause temporary blurred vision, pain, and watery eyes. And chronic exposure can cause permanent damage. Kinda scary.

Korbin, you got it right, this is from Brian at Hello Lights-

"Double ended bulbs are made of quartz glass on the outer shell as well, versus moguls are regular glass. Quartz glass does not

block UV rays coming from the arc tube, while mogul based bulb's

glass does. Hope that helps.

Regards-

Brian"

Borosilicate glass is what "pyrex" brand is made from, and it's very heat resistant. Good lab equipment is made from it - glass flasks and beakers than can go from freezing to boiling without damage.

3/8 glass shield! Holy Cow! Most fixtures use 1/8 or 3/16 at most.