# LED spot heat & water



## Revenant (Mar 17, 2007)

I've seen several how2s on making LED spots (I especially like Heresjohnny's) but it seems no one who makes them covers the "business end" with anything and I'd hate for weather to mess them up. 

1--Has anyone used any kind of transparent stuff to use as a lens to seal the end off from moisture? 

2--And if I did that, would I have to worry about heat building up? I know LEDs are cooler than regular bulbs but I hear the high-intensity ones do warm up quite a bit. 

3--If 5 to 8 hi-mcd lights would get too hot in an enclosed tube, would maybe using metal conduit or copper instead of PVC for the tube help heat-sink it? 

If you're well-versed in all things LED I'd love your input. I was thinking some LED and electronic stuff would make a great winter project since it's nice and compact and doesn't make as much of a mess as props!


----------



## dave the dead (Jan 31, 2007)

Rev, I am a newbie to led's (thanx to heresjohnny's tutorial) I can give you my observations from this year, for what i't worth....

personal opinion is you shouldn't have much of a heat problem if you cover the bulbs with a lens. The spots I made were all 5 led arrays, and I really had no trouble with heat. I never had them out in the rain, so I really can't say much about moisture. 
On halloween night, I did wrap one up in a ziploc baggie and submerge it in a cauldron full of water and an ultrasonic mister. It was a really great effect to light the mist, and I still had enough spot ability thru the layers of baggie to light up the prop over the cauldron.

so my 2 cents....no trouble with heat...give it a try if you think you need to seal the bulbs from moisture.


----------



## slightlymad (May 25, 2006)

I am not an expert either. however, I work on traffic signals these days (think large cluster of HO leds in a sealed lense) most new installs are led and are warrantied for 5 years and most last longer. In the search for a free led source I have been collecting failed "bulbs" that are out of warranty and in testing them have found it is not the led that fails but other parts of the circuit. So I would have to say heat build up is a non issue.


----------



## heresjohnny (Feb 15, 2006)

Glad the how-to is helping 

Some thoughts. First, it seems battery power seems better suited, if there is an accident and the water shorts something out it seems the battery would be much safer than something plugged in. I have run spots with 7 14,000mcd Ultrabrights for hours, and though the LEDs are mounted in plastic bottle caps, in encased in PVC tubes, I have never had a problem with heat.

I read somewhere about using film canistors to make water tight LED spots, and I was lookng at prescription medicine bottles today thinking they would work also. Put the LEDs in the cap, apply some hot glue between the LEDs and the cap, then pulling the LEDs tight against the cap should seal the holes in the cap for the LEDs. The film canistor is water tight, I was thinking it may take an o-ring to make the cap of the medicine bottle tight.


----------



## Scottzilla (Jun 13, 2007)

LEDs are pretty much waterproof, and the voltages required to drive them aren't high enough that water would conduct a significant current even if the wires leading to the LED were completely submerged. If you are really concerned you can build watertight enclosures for your spots, but I think most people just stick their LEDs out in the rain and don't worry about it. 

Just make sure you run them off of batteries or a power supply with a transformer and keep anything with AC in it away from rain/water.


----------



## slightlymad (May 25, 2006)

I read an interesting article on LEDs today that stated they disipate their heat through the power leads (the article written for 110v use) while generating very little lite bulb like heat from the business end. I found this interesting as most of use seem to use hot melt to isolate/protect our simple circuits at this very place.


----------



## buggybuilder (Jan 23, 2007)

Just my 2 cents.....we built 15 of these LED spots in the PVC tubes for our haunted trail....We put elbows on them and stuck them in the ground with the 9v battery in the tube. They lasted 2 full weekends without changing batteries and they got rained on at least twice with no ill effects. We were running the 14,000 mcd LEDs in a 6 array pattern. We plan to use even more of these next year as they are so efficient and easy and reliable. I dont think moisture is a problem at all.....


----------



## Brad Green (Jul 29, 2004)

I've used 9v powered LED spots throughout my graveyad scene encased in open-ended 3/4 thin wall pvc for the last three years, rain or shine,(I'm in FL, it's ALWAYS raining!) and they have worked without a single failure or over-heat. You shouldn't have any problems.


----------



## Koumajutsu (Aug 9, 2006)

2 words: Hot Glue

seal around the LED(s) from behind.
should be water tight enough and have no visable effect on your light output.

just my 2 cents 

I've been using 3Watt LEDs at 140 lumens of light each.
they're -supposed- to have heatsinks. but the piled up glue behind them seems to work


----------



## edwood saucer (Aug 21, 2006)

Hey Johnny...

I do use prescription tube along with your instructions to make my crude copies of your beautiful work...

They are great. Because they are self contained - the 9volt fits right inside the bottle. Secondly - when you are finished - you can invert the lid (thanks to easy opening arthritis lids) and protect the lights from harm during storage.

Which may be a bit of a null argument since I agree - the circuits are way more delicate than the lights themselves - so it may be smarter to store them with the wiring tucked away in the bottle.


----------



## Revenant (Mar 17, 2007)

A bazillion thanks guys! Online how-to's are so much better when a whole group of people can chime in with their own experiences and observations. I think in a couple of weeks I'm gonna place an order with led-hk and start getting things together.

I've been kicking around an idea: Since I plan on lensing them anyway... what do you think of just going with white LEDs and getting a pack of lighting gels to provide the color? There's more color variety available in gels, and a 10 inch sheet can yield a heckuva lotta little circles. Plus the white LEDs are brightest, at least according to some of the ebay ads. Whatcha think?


----------



## edwood saucer (Aug 21, 2006)

I'd like to see a test! (but you asked!)

Just watch out - shipping from Hong Kong sucks. It's expensive.


----------



## Spider Web (Oct 11, 2007)

I used gel filters this year on a LED spot. They work great. Nice deep, rich color.


----------



## Koumajutsu (Aug 9, 2006)

The only thing i would be concerned with is what teh gels would do to intensity. Your normal colored LED generates light in a particular color, and white LEDs are generally a bit weaker in the lumens department since they're generating light in all colors at the same power disipation as a single color LED of the same power. 
Personally, I'd rather spend a few more bucks and have a bunch of each color I think I might use, and keep them handy.
Then again, the brand I use is now being used in a 48" fluorescent tube replacement, so those likely make plenty of light, even in white.


----------



## Gory Corey (Nov 17, 2006)

OOh, I do not agree with that assessment (sitting here testing LED lamp samples that arrived friday)

White LED lamps are IME typically 2-3x stronger (testing with light meter using Lux as standard) than comparable color in same configurations, it is obvious in my testing spreadsheet.

In my previous contract manf'd lamps and the current testing lamps from another contract manf., the case is the same.

I gladly added gels sometimes 2-3 layers on a white LED lamp for more density and could still overpower comparable colored LED lamps.

Plus you have so little heat in most cases, that the gels suffer no ill effects from being right against the lamp surface. (I cannot say if that is the case with multi Cree, but I find the same approx. heat from single Cree lamps compared to 36 LED lamps (my tested max so far))

www.minionsweb.com


----------



## Gory Corey (Nov 17, 2006)

rereading the post I see you are looking to make minispots.

I would suggest once the spot is made, simply encapsulate the LED to the sleeve (very carefully) with marine grade epoxy, it is the same thing better grade LED bulb manufacturers use.

I highly doubt you will have shorting/condensation issues once done.


----------



## TommaHawk (Sep 18, 2007)

Also, your enclosed LEDs will still never get anywhere near hot enough to endanger the PVC or the plastic lense. A metal pipe would be drastic overkill - unless you plan on mounting these to a brush guard the rest of the year.

I'm in Seattle where it rains practically EVERY Halloween, and I didn't waterproof my LED spotlights. A lense would get covered in water drops. Just drilled a small hole in the bottom/back to let collected water drip out - works like a charm.


----------



## dynoflyer (Oct 8, 2006)

Same here, been making and using both 9V and wall wort powered LED spots for three years. Out in the rain, under leaves, stepped on, dropped, kicked, tripped over. 

No worries, matey!


----------



## Troy (Oct 14, 2006)

I use the perscription bottle method myself then put that inside 2" PVC. I buy the LEDS that already have the resisters and can take anything up to 12 VDC. This makes it very easy to wire them to a Walwart. I have over 15 of them in my Haunt it saves on Batteries!


----------

