Correct glands for DIY Halogen Light? -other questions too.

[jfoster33702]

I'm just taking ideas from other projects and trying to make my own DIY light. Do these glands look ok?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7576830780&rd=1&sspagename=STRK:MEWN:IT&rd=1

I saw that someone was using the metal glands on the plastic otter box 9000 - does that actually "stick" using JB Weld?

Does anyone have a good design for a magnetic on/off switch? I would like to minimize leak issues by limiting the numbers of actual holes that I punch into this puppy.

Thanks
Jeff

 

[SteveC]

The glands look good to me, but I'd like to hear from someone who knows. I did a search for magnetic switches on E-bay and found quite a few. The all say they are good for 1/2 amp, so I'm wondering if they would work.

Steve

 

[426Scuba]

The glands look good to me, but I'd like to hear from someone who knows. I did a search for magnetic switches on E-bay and found quite a few. The all say they are good for 1/2 amp, so I'm wondering if they would work.

Steve

A 1/2 amp will only work if you are using a 6 watt or under 6 bulb, or by using a relay an automotive relay is a cheap relay that will handle the amps (can be found at most auto parts stores or radio shack).
http://www.radioshack.com/product/index.jsp?productId=2062477&cp=&origkw=automotive+relay&kw=automotive+relay&parentPage=search
How to wire your relay:
http://www.installdr.com/TechDocs/999404.pdf
How to figure your lamp amperage:
http://www.angelfire.com/pa/baconbacon/page2.html

 

[bradshsi]

The glands are probably ok. However they don't say what the IP rating of the gland is. IP68 is necessary for underwater use (the max depth or pressure should be stated)

Personally I use the McMaster Carr nickel plated brass cable glands. These are rated IP68 to 300ft. I don't plan on going that deep anytime soon .

Description of these can be found on page 774 of their catalog. http://www.mcmaster.com/


As has been noted, most magnetic reed switches are too puny for switching the electrical load directly. You need to use a relay in conjunction with it. I considered this approach and decided it was too much messing around, so I used a sealed switch instead.

 

[JBowl0101]

Bradshsi:

Could you point me at a reasonable vendor (or a McMaster part number) for a good sealed switch?

Thanks!

Jason

 

[jfoster33702]

I got one from diveriteexpress.com
http://www.diveriteexpress.com/lights/ltparts.shtml
Switch and boot.

 

[clive77]

I am trying to get my hands on DIY. And i don't really know much about it. But are there IP ratings for cables? Are there cables that will be more suitable for underwater usage? Or will glands be good enough to keep water out.

Thanks

 

[SteveC]

I just ordered these glands, I'll report on how good they are soon.

Steve

 

[bradshsi]

I am trying to get my hands on DIY. And i don't really know much about it. But are there IP ratings for cables? Are there cables that will be more suitable for underwater usage? Or will glands be good enough to keep water out.

Thanks

IP ratings don't apply to cables because their rating normally is contingent on how the ends of the cable are terminated and sealed.

For underwater usage, the following are good pointers


The cable should be a good fit in the gland you select, not too big or worse too small.

It should have a circular cross section

It should be flexible enough so that you aren't fighting it underwater.

The cable outer should preferrably be solid material which surrounds the 2 (or 3) inner wires and their insulation. A lot of cables have woven material or filler at the center as well. In the case of a flood water will wick along this and leak into the other part of the light.

It's a good idea to seal the ends of your cable with silicon after you've built the light. This will prevent wicking and corrosion of the wire in event of a flood.

 

[clive77]

Bradshsi,

Thanks a million. Makes complete sense and will definitely come in handy.