Flashlight for a boat

[Packhorse]

Get a maglite and remove all the guts including the switch. Get a MR16 sized halogen bulb of desired wattage and beam angle and slap that in with a cable running out the back via a cable gland.
Simple and effective, but it will cost more than a simple 12v hand held spot light that you can pick up at any automotive or marine shop and probably perform lower too.

Now on the other hand if you really want to build something brilliant.....
http://www.candlepowerforums.com/vb/showthread.php?242941-Hexaspherical
or
http://www.candlepowerforums.com/vb/showthread.php?280742-Triple-SST-50-aspheric

 

[owkaye]

What battery do you have, and how long do you want to use the search light?

It's just a cheap car battery, and I want to use it for a couple hours a night.

 

[owkaye]

Packhorse, you suggested installing a MR16 halogen bulb in a gutted maglite. I found a new CREE bulb that's supposed to replace MR16 bulbs and I guess it might be a more energy efficient choice than a MR16 since it's a LED:

http://www.cree.com/press/mtg-mr16-pr.asp

Here's a short promo video that illustrates their internal components:

http://mtg.cree.com/

Do you or others have any opinions on the use of a bulb like this?

From what I've read CREE seems to be a company that produces high quality LEDs so maybe this new "Cree XLamp® MT-G" bulb would be worth considering. Has anyone used one of these in a flashlight build yet?

By the way, what I would really love is a search light like the ones in those two links you posted. Too bad most of the images are missing because I would love to see the pictures that were apparently visible in those threads at one time.

Edit: I found a technical report detailing the development of this new bulb. It's here for anyone that's interested:

http://www.cree.com/products/pdf/xlampmtg_mr16_ref.pdf

 

[Benson]

I think my choice for the given host would be this XM-L WF-500 drop-in http://www.dealextreme.com/products.dx/sku.58481.
However, I haven't bought one of those, so I can't vouch for the quality, and while it's specced for 12V max, your "12V" battery will be significantly over that when fully charged -- there's some risk it would fry.

I have used other WF-500 dropins in a host very much like that, no problems mechanically.

But you would need to make (or have made) a heatsink to conduct the heat out of that dropin to the body -- basically an aluminum ring that presses into the light body and makes solid contact with the dropin, either on the reflector or the brass pill (you don't need the spring on there). Is that in your capabilities?

Really, the heatsinking is an issue for any high-brightness LED setup in that host. That's probably why you're not getting any LED recommendations -- any LED that will not overheat in that host without adding a heatsink will be rather dim compared to the incandescents you can run, but if you can heatsink a high-power LED well, you can expect over twice the battery life of an incandescent the same brightness.

 

[owkaye]

But you would need to make (or have made) a heatsink. Is that in your capabilities?

Sure, that's not a problem. I can build almost anything I can understand (or see pictures of), and I learn faster from the pictures. That's why it's so useful for me to see pictures of how other people have modified their lights.

Really, the heatsinking is an issue for any high-brightness LED setup in that host. That's probably why you're not getting any LED recommendations.

I thought that maybe the reason I wasn't getting many LED suggestions was perhaps because LEDs are inferior to incandescents when used for long distance spot lighting. But I've read more since I started this thread, and it seems that the heat dissipation issues and the stability of the power source are the real issues limiting the use of LEDs for this purpose.

 

[owkaye]

I think my choice for the given host ...

Benson, are you referring to a Maglite host, or were you referring to my original proposal to use a Ray-O-Vac Industrial flashlight as the host? I'm guessing Maglite but I want to be sure. Thanks.

 

[Benson]

I meant the RayOvac.

Maglites, being metal, require significantly less heatsink/body contact, and some WF-500 dropins will get enough contact themselves. The others... Well, it's an ugly cheat, but aluminum foil is enough. An aluminum spacer would be better, just to contact the shelf in the Mag head.

But the Mag bezel's a bit cramped, you'll need to grind the threads off a WF-500 dropin to make it screw down fully, so it loses some appeal.

If you're open to changing hosts, you could just go with a WF-500 (or clone) -- metal host, takes that dropin natively, more compact than a Mag, and if you're using an umbilical, battery options don't matter. (Not all WF-500 clones are the same internal profile, so some aluminum foil is likely necessary here, too.)

 

[seven11]

owkaye,

I had the same dilemma for my boat. I didn't want expensive docking lights and really just needed something handheld that would shine for a really long distance. I think building the light yourself may be more expensive than anticipated...at least that's been my experience. I ended up purchasing a light for my boat that ended up being perfect. It's the Stanley HID spotlight. It will light up a beach from over 200 yards away and runs from a standard cigarette lighter plug or you could wire it directly to your battery. I know that if you buy this light, it will be exactly what you are looking for. A link is below. I ended up buying mine from a local meijer for $35 dollars, so if you look around at local big box stores you might be able to score a deal.

http://www.amazon.com/dp/B001U04MEY/?tag=cpf0b6-20