Cutting copper

Use snips. Get a brand new pair of jeweller's snips (Wiss G10s) with a nice tight rivet and well set blades, and don't use them for anything else.

The "ridge" is caused by the metal being folded over into the gap between the blades. Reduce the gap, reduce the ridge.

You can buy little bench guillotines quite cheaply for copper and aluminium sheet up to about 3mm thick but for stock as thin as you indicate a paper guillotine would be ample. You could probably also manage by clamping a straight edge over the material where you want to cut and using a scalpel or Stanley knife.

-- Dave Baker

I had opportunity to use one of those cheesy chiwanese made three in one sheet metal combo tools for a while. The shear actually worked quite effectively for the light gauge aluminum I was cutting. I would imagine the press brake would work well enough to make a clean right angle bend in copper, and the roller portion was functional, if a bit inonvenient to use (handle positioning). Google search Grizzly G4011 Sheet Metal Machine to see one example of 30 inch capacity for a bit over $350 US. If 12 inch capacity will do, the same outfit sells a machine of that size for about a hundred bucks less. Harbour Freight and others may well sell same or similar for less money.

Cheers Trevor Jones

I have a technique I use for cutting thin copper sheet that is laminated to PC board materials. I take a #11 Xacto blade that has been well used, and swipe the point across a bench stone. It makes it like a micro chisel, although not as acute an angle. This would make the chisel as wide as the thickness of the blade, maybe .020" (1/2 mm).

I put a ruler down as a guide and hold the Xacto knife with a grip like a fist. Then I put the blade against the material and pull it toward me. I can usually cut through the .0015" (one ounce) copper on a PCB on the 2nd stroke.

You wouldn't want to use this method except on very thin copper, and then it might buckle if it wasn't attached to something. Holding the part you want under the steel ruler might save the part, though.

This does leave a slight ridge, but you can easily slice that off with a fresh Xacto knife.

Jon

----- Original Message ----- From: "Steve B" Newsgroups: rec.crafts.metalworking Sent: Monday, January 23, 2006 7:16 PM Subject: Cutting copper

dave baker's response reminded me of my (desperation) technique. straight edge and one of those hooked scoring blades in a stanley knife. very light multiple passes (if you cut too deeply it'll dig in and rip) on a flat smooth hard surface to back up the cut (i use my table saw table). i've used this technique for cutting dissected aluminum cans for shims. score it (as deeply as you dare) and bend it back and forth to divide. i doubt if it would be possible to make curved cuts. i don't like that ridge either that's why i use this technique when i'm cutting shims out of REALLY thin stuff.

b.w.

Another method not mentioned might be acid etching. Spray all sides of the sheet with some kind of insulator (a primer or draftsman's spray) and scribe a thin line on both sides where you want the cut. Then place the sheet into a vertical-standing vat of Iron Chloride (FeCl, radio shack copper etching solution) or Ammonium Persulphate. Both work best when the solution is warmed, such as with an aquarium heater. Agitate the sheet occasionally and the exposed copper will be consumed. The least copper consumed, the longer the solution will last. Intricate designs can be made this way. Iron and steel parts can also be dipped in the solution to create a rough surface, like what is desirable on firearms.

Why not just cut it with snips and then flatten the edge using a polished hammer? Copper is quite malleable and hammers really easily.

GWE

Um... there's a "trade secret" to cutting copper sheet. My dad taught me this when I was a kid, then I heard it repeated once on the 1980's show "Half a Handy Hour".

This is THE secret to working with sheet copper:

DON'T bleed to death.

LLoyd

How true with sheet *anything*, even paper to be honest. My family can always tell what kind of work I've been doing by my injuries: burns=soldering, barked knuckles=mechanical, etc. but the really serious bloodshed always means sheet metal.

Wonder if machining is my favorite because I don't damage myself, much?

Oh yes, but speaking from direct personal experience, copper-foil cuts sting a LOT more than a paper cut.

Well, hot chips certainly get one's attention, depending on where they land...

Until a machine chews a finger

Those, still-hot toolbits, and barbed swarf under the fingernails. One does expect the occasional enthusiastic outcry, right? 8^)

I'm almost always good about still-hot toolbits. Waaaaay back (mumble) years ago in high school chemistry class, the instructor taught us: "Hot glass looks exactly the same as cold glass" as one of the lab safety rules. I've tried to keep that in mind, and usually succeed.

I use my CNC plasma machine. I cut 0.032" to 1/4" copper for hanger trinkets and such...

Very easy to do.

A coping saw - used in wood work like this - with a very fine blade does a good job. They make round blades that the slot is helix. Those are fine working.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

Steve B wrote:

There are electric shears, and nibblers that do a great job. One of the shears that is popular with roofers is the DW890, there are equivalent models with most manufacturers. It leaves a pigtail.

Nibblers are fantastic as well. Once you use one of these, and provided it's suited to the job at hand, you won't be wanting to use your snips again. Nibblers a great for the reduced injury risk, all things being equal. They leave small razor-sharp chips.

You can also play with the sheet temperature to change how "buttery" it is, and reduce edge distortion. The colder the sheet, the more it will tend to shear rather than tear.

Where can I buy .032" copper sheets, in head-gasket sizes? Any good sources? Alternately, if I get you a pattern, what kind of price should I expect to pay to have a one-off gasket made?

I googled up a ton of sources for copper. Trouble is, most want to sell you a large quantity of the stuff. I found that ebay had smaller quantities at much lower prices. You just have to shop around. Maybe you will get lucky, and someone here will have a piece.

Steve

Depends on the size and pain to do - but cutting is like nothing.

They now have all sorts of copper sheet thinner that that now!

bottom left - copper/sheet selection.

They now start at .00405 3oz Never tried that thin!

If you have dxf or bmp or graphic jpg .... I can convert easily.

send me an e-mail - no problem.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

Dave H> >