If you only need one or two, inexpensive shop lights are a probably better choice. I needed 10-12 for my photography/videography light project, so decided to build my own and save some serious cash! Like almost all of my projects, I made it at TechShop! 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. Materials Per Reflector: (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. Tools: Compass Drill Drill Bits Saw Red Handled Tin Snips (Red for right handed people, green for left) Hammer Utility knife Sand paper Drill Grinding Stone (Optional) 1 inch hole saw (Optional) Step 2: Reflect for a Moment. The ones with rounded sides give better results than the ones with sloped sides. This was about as small as I could find without special ordering them.
My bowls were slightly more than 2-1/2 inches deep so when the reflector was finished the standard lamp bulb did not rise above the reflector rim. This provided a little more protection for the bulb from accidental bumps. The bulbs I used were 23W (100 watt equivalent) CFL's). Higher output bulbs are larger, sometimes much larger. 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. I prefer to so this carefully with a compass, but alternatively you could just take a short piece of PVC pipe, eyeball it on the bowl, and trace around the inside. I have had mixed results using this method (my eyeballs may be crooked), so I use the compass to carefully mark my first opening and use it to mark the other reflectors. 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. 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. Place several small pieces of clear tape over center dot to give the compass something to penetrate. Packing tape works best, but scotch can be used if that is all you have. Now draw a circle the diameter of your knockout cap. The inside diameter of the pipe is 3 inches, so I set the compass to a little over 1 1/2 and created my circle. If you have trouble seeing your line, you can place masking tape over the edge and draw your line on that. Stack all of the bowl reflectors together and drill a large starting hole 1/2 inch from line. If you drill bit isn't large enough you can drill several holes next to each other.
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. Now we need to create a reflector to use as a pattern for the others.
Cutting counterclockwise if you are right handed with red snips and clockwise with green handled snips if you are left handed, start cutting metal in a spiral shape until you reach your line. While cutting you should be on the line or slightly inside it. The closer you get to the line the less smoothing you have to do in the next step. Using a drill grinding stone or a Dremel, smooth the opening until the knockout cap slides through with a little resistance.