1) This project is for 23W or less CFL's only! Incandescent lights get much hotter and will pose a fire risk.
2) This project involves metal cutting and grinding. Take care and use all appropriate safety procedures!
3) CFL bulbs are fragile and contain mercury vapor. Always handle them carefully with gloves and screw them in by the base rather than the bulb. Remember to always dispose of them properly.
4) Create and use this at your own risk! My CFL's don't get hot, but yours might.
Learn what to do before you break a CFL bulb!
Step 1: Get Stuff!
(1) Stainless or aluminum 'Dollar Store' bowl - $0.99
(2) 3 inch PVC Knock-out cap - $0.60
(1) 3 inch PVC pipe 2-1/4 in long - ~$0.50
(3) 3/8 inch screws #4 or #6 - ~ $0.20
(3) 1 inch #8 screws - ~$0.40
(1) 1 Inch Metal Conduit Hanger (Aka 'rigid clamp') ~$0.79
(1) Package of Metal Filled Epoxy
(1) Spray Truck Bed Coating ~ 6.00
Red Handled Tin Snips (Red for right handed people, green for left)
Drill Grinding Stone (Optional)
1 inch hole saw (Optional)
Step 2: Reflect for a Moment
I had great success finding inexpensive stainless steel bowls locally at restaurant supply stores and 'Dollar Stores'. Cheaper means thinner metal, for our purposes the thinner the metal the better. My bowls cost $ 0.99 at a local store by a very very similar name. ;) . I won't spend much more much $1.50 on a bowl unless it is for a 'Beauty Ring'. Spending a lot on the bowl at a big chain store makes this project less attractive. At a total cost around $3.00 per reflector it is an excellent deal.
Step 3: Find Your Center
Quick and easy compass method:
In higher quality bowls manufacturers often polish the bottoms to remove the manufacturing marks. In 'Dollar Store' bowls, this is most often not the case. Look at the bottom of the bowl in bright light. Often you will see rings from the manufacturing process.
Find the center and place a small dot with a pencil or fine Sharpie to make it easier to locate for the next step.
Step 4: Visualize Your Hole
Step 5: This Is Only a Drill
The starting hole is moved away from the line to give you room to bend the metal a little. This sometimes happens because the tip of the snips is too large for the hole and can crease the reflector.
Placing the stack of bowls right side up on a piece of scrap wood and drilling seems to work best. Hold the bowls firmly to keep them from slipping and go slowly to avoid ruining your drill bit, stainless is hard metal.
Step 6: Snip Snip
Step 7: It Won't Fit!
Now you can use your first reflector to mark all your other reflector bowls. I made mine in a batch, which significantly cut production time. I even stacked them to smooth them all at once!
Step 8: How Long Should It Be?
I cut the PVC with a power miter saw, but it can be done easily with a hacksaw if you are careful. You can make a flexible ruler from the factory cut edge of a file folder. Wrap it around the pipe as shown and draw the line.
Sand and smooth the edges of the pipe with fine sandpaper. If you plan on painting the reflector for a more professional look, lightly sand the outside of the pipe and the outside of the bowl until the finish is no longer shiny. This will help the paint stick. If you intend on painting the inside of your reflector white for a more diffused light, sand it also. I skipped it because the bulbs diffuser coating seemed to be diffusing the light well.
Step 9: Knock It Out
Step 10: Taming of the Screws
Install screws. PVC is soft, so the screws should bite into the material and hold the reflector firmly. You could also use PVC cement to lock the pieces together permanently. If decide to go that route, glue everything together just prior to painting. I used screws to make it easier to replace the reflector if I needed to, and since I didn't have PVC cement the screws were cheaper.
Step 11: Socket Mounting
Making the socket holder:
Take your second knockout cap and locate its center. Using a utility knife, remove the plastic bump.
Using a 1 inch hole saw in a drill, cut a hole. If you don't have access to a drill, scribe a hole 1-1/8 in diameter and cut it out with a utility knife.
Align your conduit hanger in the middle of the cap as shown. Caps vary, so you may need to trim the tab to get the hanger centered. side should rest against the tab.
Drill 2 holes at the points shown.
Cut or drill ventilation holes as shown.
Screw the 1 inch #8 screws in the holes.
Clean everything to remove any oil or debris before applying epoxy.
Following the instructions on the epoxy package, epoxy the screws to the metal conduit hanger. Allow 24 Hours for the epoxy to fully set.
The screws provide a mechanical connection between the clamp and cap. I have had mixed results with epoxy alone, it doesn't seem to stick to PVC well.
Step 12: A Smooth Finish
Disassemble and clean the reflector thoroughly with alcohol or mild detergent and let it dry completely. Any moisture trapped in joints will ruin your paint! Paint the back with at least two thin coats of black "Truck bed coating" (Not 'Undercoating') and allow to dry (I usually give it a couple of days to fully harden). This gives you a durable non-slip textured surface similar to professional photographic equipment. Another option is primer and flat black paint. It is less durable but it gives you a smoother finish.
Optionally, paint the inside of the reflector flat white to create a more soft diffused light. I didn't need it for this project.
Step 13: Profit!
Step 14: Blooper Reel: AKA Things I Tried and Rejected
2-1/2 inch PVC would be large enough and is available as electrical conduit, but they don't make knock-outs for conduit! :(
Using a hole saw to make the opening in the stainless bowls, even a famous name brand with a bi-metal blade, didn't work. I will have to revisit this at some point, I don't understand why.
One prototype used a 2 inch coupler. It was a little larger, but still gave very little room for air to move. Unfortunately it required an additional ring of pipe to lock the reflector. It didn't seem worth it to add the cost of a coupler and an extra cut for so little benefit.