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davidh
05-29-2010, 04:17 PM
i want to drill out the electric parts on an 4" seal beam. somewhere in my brain i hear "copper tube and oil" in a drill press. . . . .

then again, the brain is getting old.

how could i go about doing this and of course not shatter the lamp ?

Doc Nickel
05-29-2010, 04:29 PM
The trick I hear for drilling glass, is to set up a drill press with a copper or brass tube as a drill bit. Do whatever is necessary to make the tube fit in the press.

Mount the workpiece where the hole needs to go, and build a "dam" of modellers clay or putty or something, around the target area.

Smear some valve grinding compound in here, along with some light oil or other appropriate won't-evaporate-too-fast solvent, so the compound can flush in and out of the cut.

Start the press at a slow speed and start your cut. Now apply a weight or a bungee cord, or some other method to the drill's spider handle to produce a constant downforce while you're not there.

Now, go make a sandwich, go watch TV, start that model steam engine project, whatever. It'll take a while.

Keep in mind overtravel of the spindle if the object is hollow. Wouldn't do to have the drill break through and crack the other side.

Doc.

winchman
05-29-2010, 04:32 PM
I've used a brass tube and valve grinding paste, but I don't see why copper wouldn't work in a pinch. The modern approach would be a diamond grit hole saw.

Alistair Hosie
05-29-2010, 04:37 PM
Whay not buy a cheap set of glass drills about $6-7 bucks for five of them.Or use a smal stone instead of a drill using methelated spirits poured in a ring of blue tack-putty as a small well or moat , to keep it cool. Alistair

Hogridnfool
05-29-2010, 07:50 PM
Mask off the area you want preserved with a rubber sheet and have a go at the exposed part with a sand blaster. Don't know if if it will work or not, but I know of custom car builders that use a similar method for cutting/boring automotive window glass.

Stepside
05-29-2010, 09:40 PM
I have used both the copper tube with oil and valve grinding compound and a sand blaster to cut glass. The trick with the tube is the glass needs to be supported on the back side to make a clean exit. The sand blaster needs a resist that will adsorb the energy of the sand. Rubber would be good as would be multiple layers of duct tape or duct tape, electrical tape or masking tape with a layer of cardboard between the layers of tape. My neighbor "drills" holes in 1/2 inch glass with his sandblaster as part of his business.

rockrat
05-29-2010, 11:14 PM
Sounds as though you have a lot of "how to do it" responses. So I want to know why do you want to do it. I have my suspicions but I thought I would ask.

rock~

winchman
05-30-2010, 01:46 AM
Maybe he wants to use the reflector to make a miniature solar oven. I don't know how long the shiny surface will last once exposed to air, though.

John Stevenson
05-30-2010, 05:56 AM
I'm not sure either which part he wants but if he want the electrical bit you can get these on their own they are called bulbs.

If he wants the rest they are called light units that take bulbs.

Perhaps i'm missing something ?

davidh
05-30-2010, 02:58 PM
i found this in one of the local barns. its cast aluminum, shows "police" on both long sides with red plastic behind the letters. im guessing the orig. was red glass. the red headlamp consists of a red lense and a seal beam light behind it (it says 14 volt on the seal beam. and the seal beam is of course burned out.

i intend to mount it on a nice wood board and make a display of it using leds and batterys to make it light its colors. i thought i would like to install a ring of leds thru the back of the seal beam(thats why i wanted to drill the holes in glass) and make a slow blinking circuit for it, the "police letters will use an array of leds that were just lit.

now that i think of it, the only reason for the seal beam and glass lense both is to take up the space in front where there is a visable spacer ring. its not necessary so back ot the drawing board. . . at least for the blinking front light.

i was told thats its from a late 30's early 40's police car and was most likely mounted right in the center of the hood. kinda cool me thinks. . . .

thanks for the great ideas, i am going to try the sand blasting idea anyway, and i;ve used gorilla brand black duct tape for etching glass with sand so i know it will work for blasting for a while.

http://i260.photobucket.com/albums/ii12/tooldoc/policelite1.jpg

http://i260.photobucket.com/albums/ii12/tooldoc/policelite2.jpg

rockrat
05-30-2010, 09:01 PM
i found this in one of the local barns.

http://i260.photobucket.com/albums/ii12/tooldoc/policelite1.jpg



Sweet. I could see that sitting on my desk.
rock~