# LED Spotlight Discussion



## Zombie-F (Apr 12, 2004)

Argh, so this experiment needs a little more work. Over the past few days we've had a substantial amount of rain. The power supplies are doing just fine, there doesn't appear to be any moisture inside them. The spotlights, however, did have some moisture on the inside of the clear lens I siliconed on.

When I cracked open the spotlights, the water had worked its way all the way through the inside of the light and started to cause some rusting of the LED's leads.

In light of this, I'm putting this project on the back-burner as an over-winter project. I'll be re-designing them to better keep moisture out and do some more extensive testing before I announce how I made them.

In light of that, I busted the old floodlights out for yet another year of use. My electric bill is going to hate me this month. 

Playing "extension cord Tetris" is fun. Trying to remember which length cord went where is the best.


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## mrklaw (Nov 11, 2005)

It looks like you have made these out of PVC or ABS pipe. How did you make the lens on the end? I was thinking about trying to use clear schedule 40 pvc endcaps. They cost more, but it would be a lot easier to make them watertight. I haven't figured out where I can buy them or how much they would cost though.


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## Zombie-F (Apr 12, 2004)

I made the lens out of a thin (.010") lexan sheet by using a punch to punch out a lens of an appropriate size to fit over the front of the PVC pipe. I then scored the outer edge of the lexan with an exacto knife, sanded the end of the PVC pipe and applied an RTV primer to both.

After that, I apply a thin bead of RTV to the outer edge of the Lexan window and press it onto the PVC pipe.

It was a mixed success. Some of the spots didn't leak, but some of them did, so I was forced back to the drawing board. I still haven't worked on a solution since the failure, but I think you may be on to something with the idea of using a clear PVC endcap.

I'll have to look into if these are even something that is readily available and where I can get them.


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## mrklaw (Nov 11, 2005)

what size PVC do you use for the spotlights?


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## Zombie-F (Apr 12, 2004)

mrklaw said:


> It looks like you have made these out of PVC or ABS pipe. How did you make the lens on the end? I was thinking about trying to use clear schedule 40 pvc endcaps. They cost more, but it would be a lot easier to make them watertight. I haven't figured out where I can buy them or how much they would cost though.


Haha! Found clear PVC end caps! They're pricey, but if I can cut back on my electrical costs by switching to LEDs, then it's worth it... plus, there's no re-bulbing cost, so that's a bonus too.

Have a look:

http://www.clearpvcpipe.com/index.asp?PageAction=VIEWCATS&Category=11


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## mrklaw (Nov 11, 2005)

Wow, those prices really climb fast as the size gets higher. I don't know if I could justify building very many lights with the lenses costing that much.


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## mrklaw (Nov 11, 2005)

These links don't work for me.



kryptonoff said:


> pics
> 
> http://forums.unpleasantstreet.com/attachment.php?attachmentid=383&stc=1&d=1132620373
> 
> ...


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## Zombie-F (Apr 12, 2004)

Without a means of keeping pressure applied to the o-ring, there'd be nothing to keep it sealed.

It really is imperative you keep ALL moisture out of the chamber as the LED's leads rust very easily. In the units I had that leaked, the leads of the LEDs already showed signs of oxidation after less than a day of having been exposed to the elements.


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## Zombie-F (Apr 12, 2004)

kryptonoff said:


> hey zombie-f i have a ? on light intenisty.....i can stand about 30 feet and still see the light but not very intense after 15 20 feet .......only one way i know how to ask ? is in decibals if you double cone area or power 3 dbs increase i belive thats right........ not double......if i double leds does it get twice as bright?.......now on scale 1- 10 i say 5 if i doubled lights would it be 10 or 7 ........i know thats pretty crude and not very technical ....but
> 
> thanks in advance


I'm really sorry, but I have absolutely no idea what your question is.


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## Zombie-F (Apr 12, 2004)

I doubt it'd be twice as bright. Definitely brighter, but probalby not twice as bright. I wouldn't double the power though as you'd no doubt burn out the LED.


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## Vlad (Aug 2, 2005)

I was talking to Zombie and Kryptonoff on chat the other night, and I'm kind of baffled about all of the waterproof stuff. I just covered all of the exposed wiring and LED leads with hot glue. The only thing I left exposed was the body of the resistor, so that it can still disipate the heat. I'm going to set out a string of spots soon and let them weather out there to see what happens.

Kryptonoff, decibels are a measure of sound not light.


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## Zombie-F (Apr 12, 2004)

Vlad, at work we've tried using hot glue as a sealant in the past, and it works fine at first, but over time, the glue doesn't hold a seal and water will eventually find its way in.


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## Vlad (Aug 2, 2005)

I'll let you know. Mine won't be out for longer than one week a year, so I'm not worried about it. I can see where it might be a problem for anyone with month long displays or planning on selling them. But I'm not talking about a dab of hot glue, I'm talking about the wiring being encased in hot glue. like a scarab in resin, lol. I'm going to set some outside soon, and let the elements have crack at them and see what happens long term.


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## HibLaGrande (Sep 25, 2005)

Answer to waterproof problem... zip lock bags. Make whatever LED terror you can construct and throw it in a clear zip-lock bag.... Taaaah Daaah!


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## shaunathan (Sep 18, 2005)

We siliconed the whole light into the PVC housing we made, worked great.


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## Vlad (Aug 2, 2005)

I'm finally getting back into some of these projects. I finished some of these last night, and I'll place them outside during Xmas week while I'm off and at home.


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