Drilling Copper

I'll look at those.

Thanks! Fran

Thanks! I'll look into it. As of right now, no standard surface stamp is used due to the filing and buffing to remove them. It will take a coordinated effort between the police and the scrap yard owners to follow through with whatever method is chosen. Simpler the better. Best thing would be if the durn things weren't stolen to begin with. The cost is not in replacing the copper. It's in the repair of the overall site when the thieves tear everything up getting to the copper!

Thanks! Fran

I like the drill idea. He could make a small drill jig with a simple V pattern and clamp it to the plate on-site. Then use a cordless drill, prolly take a minute or two per plate. Use some good coated drills.

Fred

As an off the wall thought and not knowing much detail about what you are doing I have heard that government depts in the UK have tailored word proccesing systems to enable detecting of who leaked a document, whether this is misinformation or not I don't know, but from this thought can you alter each piece in such a way that it is detectable (measurable) but not necessarilly obvious. Whether your pieces can be subject to this type of procedure I don't know and whether the work involved would be worthwhile is yet another question.

Maybe a microstamp would work, in addition to the suggestion of a more obvious mark the thieves could remove. This company makes stamps that would mark copper with just hand pressure, you could mark the inside of some of the holes easily enough; jewelers use them to mark earring posts, etc.:

By stamps, I meant stampings that you pound with a hammer. (and said so). They leave deep marks, hard to buff or file off.

Obvious is OK. If it stops them from taking the copper in the first place, so much the better! ;) But being able to identify it later would be most useful. I think that is the only way we will catch the thieves. I am certainly open to all suggestions!

Thanks! Fran

Put your thumbprint on it in UV sensitive ink. Blacklight will prove it's yours

According to Don Foreman :

Hmm ... while you're about it, grind off half of one blade (using a Dremel or the like and a small grindstone, so it makes a distinctive mark unlike any just from a screwdriver bit.

Good Luck, DoN.

The problem with any small mark (say less than 1 1/2" diam) is that it is easily drilled out with a hole saw. If it's being scrapped the thief doesn't care how much it's abused. If they are currently going to the trouble of buffing and filing to remove id, they would certainly saw and/or drill too.

You really need a large part of the surface marked in such a way that it would be a lot of work to remove the marks. You want to make it not worth the his time.

How about a dye that could be rolled on, but is resistant to most solvents. Can't help with what that dye might be.

Or, the surface could be scored in a distinctive pattern. Make a tool with 3 carbide tips in a row, with distinct spacing between them. Drag this over the surface. A small area could be buffed out, but not the whole surface.

This assumes that at least one surface can be defaced (aesthetics compromised). I.e., this is not "art".

HTH, Bob

But only if they can see it!

Some time back I got a 3-letter metal stamp made (out of solid carbide) that is only about 1/32" high, and I think he does them smaller too.

'Cant give you a URL I'm afraid, as it was _some_ time back, but maybe someone here can put you on to him. IIRC he makes ring stamps as well.

With a tiny stamp like this, you can even mark the edge of a sheet of metal (mine works fine on 1mm (20G?) and it's so small the thieves are unlikely to see it.

If you are consistent with where you stamp it would make it easier for you to find and identify marked sheets/items!

Another advantage, with a stamp this small you dont need a hammer (on copper anyway) as you can just press it on by hand.

Cheers, Bob