DIY 70w Metal Halide Pendant.

[dakar]

Okay since we now have a camera that actually works here's my DIY Halogen worklight to 70w Metal Haide Conversion.
There really isn't much to it, so I didn't take everything apart to replicate the creation.

Started with a Home Depot 500w hologen Regent worklight, seen here with all the assorted pieces I removed.
http://www.captivereefing.com/richedit/upload/2kf7d3634ce6.jpg

All those brackets and the heat shield went stright to the junk bin. Removed the halogen lamp and replaced it with an Astralux 14K 70W MH bulb instead. They are a direct fit so no hacking needed on the lanp holder.
http://www.captivereefing.com/richedit/upload/2k7214541548.jpg

Wired in a Fulham HH-MH-120-70-C ballast into the little waterproof enclosure box between the power source and the bulb

http://www.captivereefing.com/richedit/upload/2k2a599958fa.jpg
I drilled some holes large enough for the wiring to fit through, they'll be sealed with silicon before put to use.

http://www.captivereefing.com/richedit/upload/2ka9519210f5.jpg

And there you have it... simple as pie... forgot I need to get rid of that stupid sticker

http://www.captivereefing.com/richedit/upload/2ka1c2bfafac.jpg

The only left to do is fashion a bracket to attach the ballast to the new pendant and add some S hooks and chain to suspend it from my shelf.

The lighting pattern from the dimpled reflector is very focused and concentrated, I'll post some more pictures of it fired up as soon as I'm ready to get the nano wet.

[jerryc]

Looks good
Just one suggestion id drill some openings in top or back to let some heat out

[Whoyah]

Looks good. How much do you think this project costs?

[dakar]

The worklight is $25-30, the bulb I got from Perpetual ($50 think he's still got a few more), the ballast I used is the real killer... the Fulham electronic ballast runs about $110, but I found a few Advance magetic's retailing for $46, so they may be found even cheaper. The work light's glass is already treated to filter UV, so it works out great for HQI bulbs.

The neat thing with the project is that with a little modification to expand the lamp holder you can fit 150 and 250 watt HQI's in there. The dimpled reflector really surprised me, the focusing of the light is much better than a smooth reflector, less restrike between the bulb and reflector.

As Jerry mentioned some ventilation would need to be incorporated for larger than 70w, with the 70 it gets pretty warm after a couple hours, but since it's designed to handle a 500w halogen bulb I think the 70w isn't an issue. If I can get my hands on a pair of M80 ballasts I want to build a pair of the 250's for our frag tank.

[flame]

Very nice project dude. Looking foward to seeing it in action

[jerryc]

If someone else is interested in doing it i bought a ballast for the one i did a couple years ago on eBay for $20.00 and still see them on their from time to time.
worked good but not as good a ballast as dakar got.

[flame]

Jerry which ballast are you talking about?

[jerryc]

Flame i just went to eBay and don't see one right at the time and don't remember the brand but it was a off brand.
Ill keep watch and post if i see some of them.
I do no it was a electronic ballast

[perpetual98]

I've still got a couple bulbs left and I'll give people deals on them from Captive Reefing. :)

[Tom McKenna]

mb im stupid but why the new ballast and not the normal bulb Im going to add some metal halide to my tank and looking for the best and cheapest way

[dakar]

Not stupid at all... I'm assuming by the normal bulb you mean the original bulb that was in there, it was a 500w Halogen, way too inneffficient (heat) and the wrong color spectrum for our uses, the halogens burn around 2900K if memory serves me right. The new halide burns at 14000K. I hacked the Halide into the halogen fixture because I didn't want to purchase a fixture and quite frankly, because I could :)

Cheapest route for halides will almost always be a DIY, magnetic ballasts can be found for cheap, best as far as type and color is a matter of perspective, appearance versus growing power. But that is beyond the scope of this thread.



mb im stupid but why the new ballast and not the normal bulb Im going to add some metal halide to my tank and looking for the best and cheapest way

[Tom McKenna]

No it isn't contnue might one hehe Im thinking of adding metal halide to my tank is why I ask I already have a orbit on it now. WIll halide bulbs work in the halogen fixture without a new ballast?#ed_op#br#ed_cl#

[dakar]

If only it were that easy, all metal halide bulbs require a ballast to fire. The majority of single ended MH bulbs run at 250v, but also require the current to be at a certain frequency, much higher than the standard 60hz than is present at the wall. That's the simplest explanation I can think of at the moment.

[jerryc]

Halogen lamps run of your wall outlet 120 volt without help

MH need a boost to start so you need a ballast to give it a boost
a ballast is just a transformer that runs the voltage up to start the lamp
from your wall outlet

[segraves1]

this is cool......so if I want to put a 250Watt bulb in, it just clips right in?

[dakar]

The 70w and 150w DE bulbs are the same length, however the 250's are a little longer. That doesn't mean that the fixture and lampholder can't be modified to accomidate a 250w bulb.

As a side note I did endup drilling a pattern of holes across the back (now top)of the fiture to allow heat to escape. It was getting pretty warm even with a 70w bulb, anything larger and it would be a 'must do'.

[jerryc]

Some folks are putting in a fan for the larger lamps

[perpetual98]

Dakar, the 150W bulbs are longer than the 70W bulbs. I speak from experience. I thought they were the same too. The 250 are pretty big, and the 400W DE bulbs are rather large.

[dakar]

Ooops... thanks for the correction! Do you have the actual length difference close at hand? I looked at them and they sure looked close, a little extra hacking on the fixture/lampholder would fix that.

[perpetual98]

Here's what I got off of the net...

70W - 4-3/8"
150W - 5-3/8"

Not much luck quickly finding the lengths on the 250 & 400 watt DE bulbs.

[jojo22]

I will be needing one of those bulbs in a few months Eric!!! You still have them?? What is the shelf life on a HQI bulb??? I might buy 2!!!