Sandwiching Metal Sheets

[DavidJHolmes]

Next part of my project...

Is it possible to sandwich a piece of brass between two copper sheets permanently and strong enough to mill into rings? Is silver soldering a possibility or would the solder not flow across the sheet completely? I'd probably be looking to sandwich either 100mm or 75mm square pieces. It would be 3mm brass between 1.5mm copper sheets if I could.

Maybe should of started with something more simple lol

Thanks

 

[NazNomad]

A metal-bonding epoxy should work.

 

[Inspector]

Look up Mokume-gane and see if meets your needs and abilities.
I'm not sure if it is done with brass and copper as there isn't a lot of contrast between the metals.
Pete

 

[Walney Col]

Even soft soldering wold hold them providing you don't go berserk with the milling.

Col.

 

[Phil Pascoe]

As above, look into mokume gane. You need quit precise temperature control for it, though, as the melting points of the materials and the solders can be quite close so if you get it wrong you end up with a puddle. I assume you're thinking jewelry? Soft solder will leave you an ugly solder line. Ideally you need a kiln or at very least a forge and a method of clamping the sheets together. It's rather like making Damascus steel but with mixed metals. I suspect it's one of those things you either go into whole heartedly or forget.

have a look into PMC - the newer PMCs you can fire with a torch.

 

[dickm]

......... and if anyone has a copy of the standard text on moku gane for less than 500 dollars, my daughter would probably buy it off you .
She's done a couple of courses on it in the US, but still hasn't managed to meet the guy near Perth who is the UK guru.

 

[DavidJHolmes]

Thanks guys.

Mokume-gane is not really what I'm after. I'm literally after a straight sandwich of copper then brass then copper. These would be milled into rings and polished. Maybe if I'm clever enough chamfer the edges slightly. They are going to be spacing rings for wooden rings that will turn between the metal ones.

I'll look up metal epoxy. Didn't think about the solder lines. Any other methods that would be possible?

 

[Phil Pascoe]

We weren't suggesting mokume per se, but to point out the difficulty of joining the sheets. You can colour epoxy - maybe accept the fact that you will get a line and emphasise it?

 

[DavidJHolmes]

Ah ok my bad, I misunderstood. I'll have to have a play with some bits and see how the edges polish up with either a solder line or an epoxy line. I'm wondering if I could hide the solder line by running some grooves over the joins.

 

[Jake]

Rather than epoxy I would look to structural acrylics.

 

[Cheshirechappie]

Structurally, all the above suggestions would work. The most tricky would be silver soldering, because your technique would need to be good to ensure even flow of solder.

However, I think there may be an aesthetic problem. All those methods would leave a witness of some sort at the joint-line; either a fine line of solder, or a tiny gap.

I think I'd try cutting the individual sheet components just over finished size (by just over I mean about 1/2mm or less), then join them with an engineering adhesive, followed by light peening of the edges before final clean-up. With luck (and maybe a couple of practice pieces using bits of scrap), that will ensure that all joints are closed up tight on the edges, and remain closed up after final sizing and polishing.

It may be that a tiny gap is of no account, in which case cut out components, glue up, allow to cure thoroughly, finish to size and polish.

 

[Inspector]

Or you could highlight epoxy joints by colouring the epoxy black.

I have something else for you to consider. Use a ring core to hold the washers of the copper / brass and skip the solder etc., altogether. Also the wearer won't get green finger from the copper.

http://www.bangleguy.com/RIng_Supplies.html

Pete

 

[woodfarmer]

Why not use solid brass and then copper plate it ?

 

[DavidJHolmes]

Why not use solid brass and then copper plate it ?

I wanted a brass strip through the middle. However I did a bit of 3D modelling and not sure if I like it now so might just do copper throughout.

 

[marcros]

you would have a brass strip exposed when you mill it.

 

[ghettoblaster]

The method used to do this in industry is called explosive welding. Two or more dissimilar metals can be fused with a controlled explosion. Probably a bit out of reach for the home gamer and may raise a few eyebrows but interesting non the less. Here is a video abut it. Fascinating stuff! https://youtu.be/2u51tJdRDK0

 

[DavidJHolmes]

The method used to do this in industry is called explosive welding. Two or more dissimilar metals can be fused with a controlled explosion. Probably a bit out of reach for the home gamer and may raise a few eyebrows but interesting non the less. Here is a video abut it. Fascinating stuff! https://youtu.be/2u51tJdRDK0

:shock:

Could imagine the neighbour's reactions!