RGB Pathway Lights

I pride myself (perhaps more than I should) on the efficiency of our display.  We can currently run the entire show on a single 15 amp circuit!  With over 10,000 lights the only way this is possible is by using LEDs.  These diodes use roughly 10% the electricity of traditional christmas lights and have a brighter and "true color" hue that makes them unique.  Because of this, they also don't look that great next to traditional bulbs because the brightness, colors, and directional glow are different.  When I needed a solution to light up our "tune to" sign, I looked at lots of different spot lights on the web and in stores.  At the time retailers weren't stocking a large selection of LED spots and while that has improved, they are still VERY expensive.  After spending $30 on a bulb, it pained me even further to come to the conclusion that I still needed a fixture to house it in (most of these bulbs are not weatherproof) as well as a transformer.  The transformers run about $80 and the cheapest fixtures are at least $20!  Being a cheapskate and a proud DIYer, I came up with these simple PVC housings and at less than $5 each and with some improved sourcing on the bulbs, I can now do the whole assembly for less than $20.  It's also a pretty easy project, my two year old son enjoyed working on it with me!

MATERIALS LIST - Enough to build 4 MR16 Spot Lights
  • Instructions printed fromwww.lightuplawrence.net for free of course!  Christmas Lighting is an obsession that is meant to be shared!
  • 4 1-1/2" to 2" PVC Reducer coupling, $1.18 at big box home improvement center.
  • 4 1-1/2" PVC Cap, $0.83 each
  • 1 2' section of 1-1/2" PVC pipe, $3.24.
  • 8 1/2" PVC Street Elbows, $0.81 each.
  • 1 2' section of 1/2" PVC pipe, $0.94.
  • 1 can PVC cement, I had some already but it usually runs about $5 a can.
  • 1 small bottle of super glue, I like Jet brand or Loctite, usually about $3.
  • 2 2" acrylic snap together spheres, $0.99 at Hobby Lobby
  • 1 package heat shrink tubing, available at Radio Shack
  • 4 MR 16 socket base, I ordered mine from MRsixteen.com for $0.95 each.
  • Spool of UV Rated Low Voltage wire, I got mine on clearance 100 feet for $17.00
  • 8 Waterproof wire nuts, I used the kind meant for underground sprinklers.  $0.60 each.

  • Needle Nose Pliers
  • Wire Nippers
  • Small drill bits, 1/8" and 3/8"
  • Cordless Drill
  • Butane Torch
  • Soldering Iron with pointed tip
  • Flux core solder
  • Saw to cut PVC pipe, I used a table saw but a chop or even hand saw would work as well.
  • Large Hammer or Mallet, I used a 5 lb. sledge.
  • Tape Measure
  • Sharpie Marker
  • Hot glue gun


To begin we will construct the bulb housing.  This consists of the 1-1/2" to 2" reducing coupler and the 1-1/2" cap joined together with a small section of 1-1/2" PVC Pipe.  The flare inside of the reducer is exactly the same angle as the back side of an MR16 bulb and the inside diameter of the flare holds firmly the 2" Acrylic sphere. 


To join the two pieces we need to measure how far each one will slip over the 1-1/2" Pipe.  I show my measurements here and guess that most of these fittings are of similar size and construction, however, I still recommend that you measure your specific pieces to make sure your pipe is cut to the correct sizes.  To do this slide the reducer onto the pipe as far as it will  go (you may need to use a mallet or hammer) then mark it's edge with the sharpie.  Remove it (may also need a hammer ;) ) and do the same for the cap.  When both of these are measured, add the two measurements together to get the total pipe
length.  We will need to cut 4 of these, one for each spot.


To cut the individual sections of PVC pipe, I set up my rip fence on my table saw even to the end of the pipe and used an extension on my square to hold the pipe even to the table top.  You want to adjust your blade height to just above the height of the pipe, in our case about 2".  When the blade is even to your measured mark (mine was about 1-7/8") turn on the saw.  Allow the blade to come up to full RPMs then slowly move the piece forward into the blade.  I use a Red Devil fine toothed blade, it works great for both wood and plastic.  After making the first cut, I moved the rip fence 2" towards the blade, the blade width accounts for the additional 1/8" in our measurements.  As I stated earlier, you could also use a compound miter saw, a radial arm saw, even a sawzall.  Just make sure that your cuts are straight and square and free of any rough edges. 


In order to assemble the pieces, coat the inside of the coupler as well as the cap with PVC cement.  I used a wet or dry PVC cement because it's what I already had.  After coating each piece, assemble them as shown on the right.  Now chances are that the pieces will be snug to begin with, more-so after the addition of the glue.  Snug them together by hand as best as possible and in a timely fashion move to the next step.


As I said in the last step, chances are you will not be able to completely close up these two pieces by hand.  We are working with very tight tolerances so the assembly is more than likely going to take some persuasion.  I used a very low-tech approach to this...  a big hammer!  Setting the assembly cap-side-up on my garage floor, I tapped the top a few times with the sledge to get the pieces to slide together and fully seat.  You may have some excess glue squeeze out at this time, wipe it off with a damp paper towel.  We want the surface to be nice and clean for paint.


Now the male end of the street 90 is a little over 3/4" in diameter.  We want a snug fit but unfortunately not that snug.  You have two options, you can either sand down the nipple end with a dremel or similar tool or you can over drill the hole. 



I started out with a spade bit to bore the 3/4" hole and used a standard forged bit to ream out the hole to a little more than 3/4".  BE CAREFUL when doing this, this very bit almost cost me my wedding band and a finger about two years ago.


Next we want to prepare and insert the two elbows.  I suggest dry fitting them in the housing first, when you are satisfied that it fits snugly, coat the rim edge with a small bead of super glue.  Insert the elbow all the way into the housing then run another small bead of super glue along the jointed edge.  I know that standard PVC cement could probably accomplish this as well, but it tends to be messy and I want a nice finished edge on the outside.  The goal with these type projects is to get as close to a professionally manufactured item as possible while spending little to nothing and gaining the satisfaction of doing it yourself!


There is no glue or any adhesive of any kind in the joint between the two street 90s.  This allows you to adjust the angle and rotation of the fixture head.  I rely just on the tension and friction of this joint and haven't ever seen a need to make it permanent.  The stake portion of the fixture is just a 6" piece of PVC with an angled cut at one end to make it easier to push into the ground.  That's it!  The housing portion of the fixture is done now.  Next we'll move onto the lens and the wiring.


Next we want to go ahead and paint the housing.  I
like using Krylon Fusion as it is made specifically to bond to plastic.  I know there are other brands, I've even tried a few and none of them have performed as good as Krylon.  I know it stinks to pay $6 for a can of paint but if you want the best results bite the bullet and do it.  For this project, as these are going in my flower beds, I used their hammered metal finish in a dark brown color.  Start with a light coat and slowly build up.  For the best results I think at least three coats works.  You also want to coat inside the housing, though not as thick.  If the paint gets too thick on the inside the lenses won't fit properly.


To make the lenses I use these small acrylic decorator balls available from Hobby Lobby.  They come in many sizes but the 2" balls fit exactly inside the flared housing end.  The only preparation that is needed is to remove the small loops.  Since these are acrylic they scratch easily and will crack if stressed.  To remove the loops I apply gentle but firm pressure with a pair of pliers or wire nippers directly at the joint.  You may end up with a small nub or bit left on the edge, that's OK, it will help the lens fit tight.


Because I dry fit the lens there is a chance that water or moisture can make its way inside.  Most MR16 bulbs are not meant to be used outside, especially the LED ones I plan on using, so I drill a 1/8" diameter hole on the underside of the housing to allow for drainage.  This also keeps the lenses from fogging up on humid days.  Not sealing the lens also allows me to remove it should I ever need to replace the bulb, though with a typical life of 30 years for the LEDs I hope I don't!  Drill the hole right at the line formed on the cap end of the housing and keep it at 90 degrees to the surface.  Next we want to drill a hole in the stake portion of the fixture to allow our power wires to come out.  I use a 3/8" bit and start out square then rotate the bit down until the bit finds it's way up into the elbow. 


For the wiring portion we're going to keep it pretty simple.  I order these MR16 bulb bases online from MRSixteen.com.  They are a nice ceramic base with cloth covered wires.  Start out by tinning both the ends of the bulb base and the UV rated low voltage wires.  I strip about 1/4" from the ends of each.  Then slip a 1" section of heat shrink tubing onto the bulb base end.  Solder the ends of the wires together then cover the soldered joints with the heat shrink tubing and shrink away!  I wrap over that with a small section of black electrical tape as well.  You want to make sure that when the wires leave the housing the entire soldered section is inside.



To thread the wire through the housing, disassemble the stake portion from the housing.  Run the wires through the head of the housing first and pull it down a bit but leave enough to be able to fit the bulb into the wires.  Run the remaining wire through the lower stake portion of the housing.  By rotating the wires through the elbow they will catch on the hole we drilled earlier.  Use a pair of needle nose pliers to pull the tail end all the way out.  I used an 18" piece of wire so I had some play with where I decide to locate the housings in my flower beds.



The last thing we need to do is insert the bulb!  The bulb in the picture is a standard 12V halogen but I intend to use color changing LED bulbs for my final installation.  After connecting the bulb to the wires, dry fit it to make sure it fits snugly.  Put two small dabs of hot glue on the angled inside of the housing then firmly press the bulb down into it.  DON'T pull on the wires, you don't want to pull them out of the bulb.  When the glue has dried, slowly fit the lens down onto the inside of the bulb housing.  The lens should fit snugly against the inside edge of the  housing. 



The bulbs I ended up using for the permanent installation I got from an on-line retailer called Maxxima Style.  These are their MR16 bulbs in cool white.  We also use their warm white bulbs inside the house and LOVE them.  They are about $10 each and Maxxima has great customer service.  We had a few bad bulbs, contacted their customer service, and had replacements sent free of charge. 
We're DONE!  A great looking, easy to assemble housing for your low-voltage lights at about $5 each!