Building a water cooled LED fixture

[Paul B]

I started making the frame of my water cooled LED fixture. Now I am going to clean it up and connect the LEDs to it, them build a radiator. Does anybody need a water cooled LED fixture? Of course not. It is just very cool.




Here is a better picture

 

[DaveK]

This is an interesting project. And I can see how water cooling would allow you to mount a lot of LEDs on a very small area.

I do have one question for you. Don't you worry about the copper pipe around SW? I sure wouldn't want any water on the copper pipe dripping back into the system, and salt water splash does seem to get all over a reef system.

 

[Paul B]

Dave, there will be a plexiglass shield under the entire fixture for splashing. I am not worried about the copper. Of course if it falls in the tank, I will have to take up stamp collecting.
I am just doing this as an experiment because I am sure you realize, it is not needed. It's just for fun. And if it don't work, I know where the scrap metal yard it. I just think it is a cool project.

 

[Squatch XXL]

What sort of cooler will this be attached to? I used to get into absurd stints of diy, and about 10 years ago I machined (terribly) a copper water block from a bus bar. I used a mag drive pump for circulation through a 89' Chevy Suburban Heater core (no ac). The fan was industrial, and made too much noise....that and CUT headphone wires in 6 places. For a computer, it made too much noise. For a fish tank, it would be quite silent lol.

 

[Paul B]

I will probably also use a heater core. I wanted to build a radiator from 1/4" copper tubing but it is a pain to get small rigid tubing. I have to drive 30 minutes for it and I don't want to do that. I also have to drive 45 minutes in the opposite direction to get the 6' of plexiglass I want to use as a shield. I have smaller pieces but I would like to make it in one piece. I just came back from Radio Shack to get thermal adhesive and they looked at me like I had two heads. They sell cell phone cases, batteries, robot dogs, MP3 players and headphones but almost nothing in real electronics. That is a shame. As a kid I could go there and get transistors, resistors, motors, solder, tiny light bulbs etc. now unless it is a stupid cell phone accessory, they don't have it so I have to get it on line. It drives me crazy that no one does anything anymore or knows how.

 

[Paul B]

I had to order the thermal adhesive on line because Radio Shack now only sells I Phone cases and little else. So while I am waiting I am making copper disks out of flattened copper pipe and soldering them on to the tubing to give a flat surface for the LEDs.
I used to have a bunch of sheet copper but I can't find it so instead of driving for five minutes to get some, I am using copper pipe and stamping out copper disks with a Whitney Punch. It only takes a few minutes to make 10 of them.


Here are a couple soldered on with an LED laying on it.

 

[Squatch XXL]

because Radio Shack

I was looking at your cooler layout. Which end is supply/which is return? Would you need/want any sort of balance valve to push coolant to the further leg?

 

[cracker]

COOL!

 

[Paul B]

Squatch, thanks but I tested the thing with hot water and all 3 legs get the same amount of water. I also thought I would have to balance it out but it seems to be fine the way it is. Remember, that short piece of pipe is not piped through. It is just a support soldered on to the outside of the pipe. I rounded it off to look better.

 

[Squatch XXL]

It is just a support soldered on to the outside of the pipe. I rounded it off to look better.

Ahhhhh! I thought it was connected through a pair of tees. Ya that should certainly work a treat! I will continue to watch this develop.

 

[StevesLEDs]

What is the name of that tool that is basically a metal hole punch? I need to get me one!

Jeff

 

[Paul B]

That tool is called a Whitney Punch. It comes with about 6 different size dies and can punch holes in metal about as thick as a penny. It comes in very handy and I have used them for many years as an electrician. I understand that they are not very cheap.

 

[StevesLEDs]

Thanks. Looks awesome, I'm ordering one. http://www.zoro.com/roper-whitney-h...gclid=CMWI6ZXLnckCFYM8aQod4u0KWg&gclsrc=aw.ds

$78.

 

[Paul B]

Yep, that's it. Mine is very old and comes in a metal case. They are a very strong, well built tool and not a Girly Man punch. Do you have a lot of holes to punch?
I broke one of the dies in my set and some day I will order it. It is not a tool I use every day but I need it maybe twice a year and when you need it, it really comes in handy

 

[StevesLEDs]

Well, right now we are using our CNC plasma cutter to make holes, however, sometimes holes are missed, since no machine is perfect 100% of the time. It is a hassle to go back and drill it manually since drill bits migrate in sheet metal. This type of punch would make short work in aluminum sheet.

 

[Paul B]

It will be very good on aluminum and makes a nice clean hole, better than a drill.

 

[StirCrayzy]

Good adaptation of cooling process Paul.
those of us running liquid cooled PCs know how efficient slow moving water and copper can keep things under control.

Glad you chose a splash shield for this one.

 

[Paul B]

Yeah, the absence of a splash shield on my existing light was a mistake.
I punched out and soldered on the 70 copper disks that will support the LEDs. Now (if I get time) I will clean it up more and shoot the entire thing with some clear coat because copper turns green and ugly. This way my Steam Punk look will last. But before I do that, I will make and solder on the supports for the plexiglass shield and also the supports to hang it over the tank. I am waiting for the thermal adhesive. I still have to either build or buy the heater core for the cooling.

 

[Squatch XXL]

I still have to either build or buy the heater core for the cooling.

I don't know how "DIY" you want this to look, and I don't know your total thermal needs.....But I would tell you that IF you can pick up any automotive radiator, you should be able to get away with 100% passive cooling. A heater core would require a fan for sure if everything I read about LEDs and heat is true.

For what you can snag a used heater core from the web, it is preposterous to build one. I have had a few water cooled custom pc (I did all the diy on them) over the years, and each had a different heater core to fit where I wanted it to look and be the coolest. I never paid more than $30 and they beat the snot out of products specifically for the pc...it just required some DIY fittings and some solder.

 

[Paul B]

I have quite a few auto junk yards here so a heater core will be easy. I probably already have the fan. I think I may have 10 fans. Adapting it to work on this system will be easy.
I would rather build the radiator but it is not easy getting 1/4" rigid copper tubing and I don't want to use flexable tubing