Cutting curves in 1mm thick copper sheet

[Brian JohnParticipant @brianjohn93961]

I want to cut some curved shapes in 1mm thick copper sheet. It is the base plate for my boiler. The heat is being transferred from the flame under the boiler to the reservoir of the spirit burner so I thought I will divide the base plate ie separate the section with the spirit burner from the section with the boiler.

Can I use a jig saw with a metal cutting blade for this. I do NOT want to try doing it with a hacksaw…not again ! I have not used a jig saw before but I will buy one if it can do this job.

[Brian JohnParticipant @brianjohn93961]

[Roger Provins 2Participant @rogerprovins2]

Yes, but get the finest toothed (most teeth per inch) metal cutting blade you can find. Some people recommend sandwiching between hardboard or MDF and cutting the whole sandwich but I've not found that necessary.

Roger

[JasonBModerator @jasonb]

Assuming you are only cutting a 2.5" dia circle you may find it difficult with a jigsaw. I'd use a holesaw if its a complete circle you want to cut out.

[Peter BondParticipant @peterbond14804]

Jeweller's saw; I'd probably use 2/0 blades (and wax the back of the blade). Cut to the outside of the scribe line, file to the line at 45 degrees then gradually file it square (to the face that is, no point cutting a circle if you wanted a square…).

If I were doing 50 or so I'd make up a punch & die and press it…

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Peter Bond on 05/02/2015 19:20:14:

Jeweller's saw;

.

+1

and you want at least three teeth to the thickness of the material.

MichaelG.

[JasonBModerator @jasonb]

Given the previous problems that Brian had with a hacksaw I can't see him managing too well with a piercing saw. Throat may not be deep enough anyway to reach the middle of the base plate

[Peter BondParticipant @peterbond14804]

I admit I gave up on trying to work out whether I had 3 teeth in the material – I tend to pick the blade according to how coarse the work is. If I'm sizing a ring I'll use a coarser blade as they track better in thicker material, while for finer work I'll go for something a bit more refined. 4/0 is my go-to blade for cutting 0.7-1.0mm sheet, although if I'm piercing thicker steel (around 3mm) I might well use a 4. The blanking dies I've been cutting in 1/16 O1 I've used 2/0 although the shapes haven't really needed blades that fine.

They're a more delicate tool than a hacksaw, requiring a gentler touch. As for depth of throat – OK, I've got between 1 and 8" saws but you can twist the ends of the blade 90 degrees and cut across; it's a bit of a bodge, but it can be helpful.

If you want a gucci sawframe then I like my Knew Concept frames – they are a bit Marmite though; some people don't get on with them at all. That said, I use a couple of much, much cheaper frames as well – sub £10. Just don't skimp on the blades and use a bench pin to support the work.

[Michael GilliganParticipant @michaelgilligan61133]

**LINK**

Worth a look, Brian

MichaelG.

Edited By Michael Gilligan on 05/02/2015 21:01:13

[Peter BondParticipant @peterbond14804]

I'd personally advocate Cooksons, Sutton Tools or H S Walsh as suppliers with better customer service due to a rather significant run-in with Cousins; YMMV.

[Michael GilliganParticipant @michaelgilligan61133]

No argument with that, Peter

… I just grabbed the first link showing a range of frame sizes.

The other obvious choice for Brian would be a Hegner Saw, or one of the cheap clones.

MichaelG.

[John BaguleyParticipant @johnbaguley78655]

For copper that thin just use decent hand shears. Cut a square and then trim to shape.

John

[Gordon WParticipant @gordonw]

I would use tinsnips for this job. I do use a jigsaw quite a lot for metal cutting, as said get good blades . For small radii you can grind the back of the saw blade.

[Ian S CParticipant @iansc]

I agree with John, bigger and better tin snips/Gilbows, or a pair of Aviation snips. Mark the circle with dividers, or with a scriber around something round. Cut close to the line, and finish it with a file to the line.

Ian S C

[JasonBModerator @jasonb]

Before anyone else suggests methods that won't work I'll clarrify whats wanted.

The heat from the boiler burner in the left of these cylinders is being transfered to the liquid fuel in the one on the right. To isolate the fuel from the heat Brian wants to cut away some or all of the copper so the heat cannot get to the bit under the fuel container. So tinsnips won't work, a hole saw would do it if the bit was completely separate or piercing saw with a deep throat but Brian does not get on well with saws. Those a 2.5" dia cylinders

Something along these lines

 

Edited By JasonB on 06/02/2015 11:32:38

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 06/02/2015 11:22:46:

Before anyone else suggests methods that won't work I'll clarrify whats wanted.

Something along these lines

.

Thanks, Jason …

Presuming the absence of a Mill & Rotary Table … I still think it's job for a Piercing Saw / FretSaw / ScrollSaw of some description. The fact that Brian has had one failure with a hacksawing job should not put him off using these tools. He has shown great aptitude with his Silver Soldering, so I would be really surprised if he cannot master the saw.

MichaelG.

Brian: Apologies for talking about you, rather than to you … but it seemed easier to respond to Jason.

[Brian JohnParticipant @brianjohn93961]

You have the right idea but I was going to separate the section of copper that supports the spirit burner from that which supports the boiler firebox. I wish I could draw what I want ! I will try to sketch the wavy line I intend to cut in the copper.

The fret saw is a good idea but surely it would take ages to cut through metal ?

What about my initial idea of buying a jig saw with a metal cutting blade ? Wouldn't this do the job or are they no good with curves ?

[JasonBModerator @jasonb]

If you are thinking more like this then yes a jigsaw will do it, 10mins with a handsaw will also do it even snips could be used but they will tend to distot the sheet which will need flattening. Sketch what you are thinking on a bit of paper and then photograph it and post here.

[Speedy Builder5Participant @speedybuilder5]

Assuming that you can start a jig saw off from a pre-drilled hole, Place your copper sheet on top of a piece of foam insulation which is the thickess of the maximum travel of the blade plus a bit. Put masking tape onto the top surface of the copper sheet to protect it from scratches. draw your circle. Wear goggles (Copper swarf in your eye is not good – and I mean it). Now use your jig saw with the fine metal cutting blade. They do make narrow blades for cutting small curves.

I used this method to cut out a weather vane of a man leading the plough.

BobH

[Brian JohnParticipant @brianjohn93961]

Jason : that is exactly it ! Can you read minds ?

I find tin snips useless as they distort the metal too much.

I am not sure that a hacksaw can cut curves like that ?

Edited By Brian John on 06/02/2015 13:07:40

Edited By Brian John on 06/02/2015 13:15:49

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 06/02/2015 11:37:25:

Posted by JasonB on 06/02/2015 11:22:46:

Before anyone else suggests methods that won't work I'll clarrify whats wanted.

Something along these lines

.

… I still think it's job for a Piercing Saw / FretSaw / ScrollSaw of some description.

.

I retract my previous advice, in light of the actual requirement.

… except, of course; I must mention that a Hegner Saw would eat a little job like this.

MichaelG.

 

Edited By Michael Gilligan on 06/02/2015 15:38:00

Edited By Michael Gilligan on 06/02/2015 15:40:04

[Peter TuckerParticipant @petertucker86088]

Hi Brian,

My suggestion is to use a nibler. Which ever way you I wish you the best of luck.

Peter.

[Neil WyattModerator @neilwyatt]

Bet you could get it laser cut for peanuts.

Wouldn't brass be better than copper for this job anyway?

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 06/02/2015 17:54:17:

Bet you could get it laser cut for peanuts.

.

Or, you could buy a Boiler … [or maybe an electric Motor ]

Where does outsourcing end ?

MichaelG.

[Peter BondParticipant @peterbond14804]

Posted by Michael Gilligan on 06/02/2015 15:29:53:

I retract my previous advice, in light of the actual requirement.

… except, of course; I must mention that a Hegner Saw would eat a little job like this.

Nah, I'd still pierce it   Something to do with the old saw (?!) about what everything looks like when you have a hammer.

I'm not sure that I should thank you for mentioning the Hegner saw though… I suspect that might save me time on a few jobs; need to work out if it would save enough to warrant the expense.

 

Edited By Peter Bond on 06/02/2015 18:12:31

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