Are metal halides dangerous?

[trainfever]

Well maybe not dangerous. I am just curious if anyone has ever heard of a metal halide bulb exploding from being so hot and then having water splash on it. Do the bulbs get that hot? How far above the water should the bulb be mounted? Do you have glass between the bulb and the water?

 

[thegrog]

Yes, they can explode if water splashes on them. More likely that they will just crack or break open. They are hot enough to cause a very bad burn if touched for even a fraction of a second (trust me on that, it hurts like hell too!!!)
You have to keep them 10-14" away from water surface.
No glass between them and the water. Two reasons. First is that the glass filters out necessary light from your inhabitants. Second is that the glass will trap in heat and your tank will get very hot, very quickly.

 

[theappe]

Yeah, they can explode from heat/splashing.

 

[zman1]

Originally Posted by trainfever
Do you have glass between the bulb and the water?
All the other parts you asked about have been answered. The commercial mini pendants have UV glass (not part of the bulb DE). So if you are hanging an enclosure yes I'd use the glass on the fixture. I would not use glass tops of a tank between the bulbs and water. I hope I am making sense here.

 

[trainfever]

I plan on building a canopy and mounting the bulbs inside. I have a canopy that I built and I have VHOs in it. I have access to hundreds of ballast components and bulbs and sockets.

 

[zman1]

Do you have reflectors?

 

[1journeyman]

Originally Posted by TheGrog
No glass between them and the water. Two reasons. First is that the glass filters out necessary light from your inhabitants. Second is that the glass will trap in heat and your tank will get very hot, very quickly.
I assume you mean in addition to the glass on the pendant itself?
Yes, bulbs can/will shatter if hot and splashed. Every pendant I've evet owned with my HQI's has come with a sheet of glass. From what I understand, unshielded bulbs produce harmful UV rays.

 

[thegrog]

Originally Posted by 1journeyman
I assume you mean in addition to the glass on the pendant itself?
Yes, bulbs can/will shatter if hot and splashed. Every pendant I've evet owned with my HQI's has come with a sheet of glass. From what I understand, unshielded bulbs produce harmful UV rays.
Yes. If the pendant comes with glass, use it. I thought he meant a layer of glas on the tank.
Mostly the DE bulbs need it as the mogul ones have the glass layer built into the bulb itself.

 

[1journeyman]

Originally Posted by TheGrog
Yes. If the pendant comes with glass, use it. I thought he meant a layer of glas on the tank.
Mostly the DE bulbs need it as the mogul ones have the glass layer built into the bulb itself.
Right on. Figured that's what you meant but wanted to clarify.

 

[trainfever]

Originally Posted by zman1
Do you have reflectors?
I have sheet metal and I plan on bending my own reflectors to fit inside the canopy.

 

[zman1]

Just wanted to make sure you were considering them in your plans

 

[thegrog]

Originally Posted by trainfever
I have sheet metal and I plan on bending my own reflectors to fit inside the canopy.
Careful. A lot of sheet metal is not reflective enough and will quickly corrode when exposed to salt mist. Will loose reflectivity and may even leech metal into your tank.
Better off going with a designed reflector. Not that expensive and worth the money. I got one for around $35 and it worked great!

 

[trainfever]

Actually it is aluminum in a coil roll. I am going to polish it before I bend it and mount it in the canopy.

 

[thegrog]

Originally Posted by trainfever
Actually it is aluminum in a coil roll. I am going to polish it before I bend it and mount it in the canopy.
Hmmmmm....interesting. :thinking:
If you have the tools and the know-how, then go for it.

 

[trainfever]

I have a complete machine shop in my basement. I do gunsmithing work, building custom rifles. I also have plenty of polishing wheels for bluing guns and plenty of Simichrome polish that I used to use for polishing my motorcycle. I also have a brake for bending the metal.

 

[sign guy]

Originally Posted by trainfever
Actually it is aluminum in a coil roll. I am going to polish it before I bend it and mount it in the canopy.
what alloy? and when you say coil do you meen master coil or channel coil also who sold it to you ? the reson I ask is I work for an aluminum co. and I know 99% off alluminum is not gonna be safe

 

[trainfever]

It is the metal used for capping and flashing roofs. It is called coil.

 

[sign guy]

unless it is anodiozed witch most roof flashing is not, it is a baked on clear ploly base that would corode after a few months. I would stear far from that rout.

 

[sign guy]

btw that is probably .032 gauge 3031 channel coil