Mama Bear wrote:
zxcvbob wrote :

Ian Stirling wrote:
In sci.engr.lighting Mama Bear wrote:
I've done some research and pretty much know what I'm
looking for now.

I'd like to find a nice quality polished reflector like at
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7770696002
with a 150-175 watt lamp and ballast similar to the wide
spectrum of a Hortilux Blue.
You can construct a functionally identical reflector out of
cardboard, contact-glued on foil - shiny side out.
With care, you can actually get it to look as good, if not
better.

White paint is actually more reflective that aluminum foil.

Cardboard will likely burn up in close proximity to a 175W
lamp like that. Make the reflector out of metal flashing and
paint it flat white enamel.

That's why I'd really rather buy something like in that auction,
just to play it safe.

You also need to be careful about your lamp selection if it's
not in an enclosed fixture.


That's another thing I've heard about using this for grow
lighting. If a drop of water splatters up on the lamp, poof, $$$
down the drain. I see some fixtures that are sealed, but then you
get the heating problems.





You don't have to worry about a stray drop of water somehow getting to
the ceiling and hitting the lamp. HID lamps can explode on their own
when they get old. ==(8-0

If the lamp is designed for open fixtures, the outer glass is strong
enough to contain the explosion if the inner capsule bursts.

BTW, I have a surplus 400W HPS security light in my basement that I use
to keep plants alive in the winter. It's adequate, but the plants like
the triphosphor fluorescents better.

Bob