Welding and Metalworking - Welding Copper Wire? [Merged threads]

I have some 4 gauge copper wire I would like to do some crafting with. It meets our needs for framework and it's bendable but will still support lightweight items.
How do I weld, fuse or otherwise join it together? I tried a propane torch but it's not hot enough.
My wife and I want to try to build a fountain using this wire.

I have some 4 gauge copper wire I would like to do some crafting with. It meets our needs for framework and it's bendable but will still support lightweight items.
How do I weld, fuse or otherwise join it together? I tried a propane torch but it's not hot enough.
My wife and I want to try to build a fountain using this wire.

copper can be welded using a TIG welder but I suspect you do not have one setting in the garage right now.

an alternate, if it provides enough strength for what you are doing, is to solder the pieces together. That can be accomplished with a propane torch unless the size of the wire acts as a heat sink and removes the heat as fast as you apply it. In that case, a MAPP gas torch should suffice.

the next step would be brazing. This is similar to solder but uses a higher strength material as the bonding material. It also requires more heat. A MAPP torch will provide enough heat generally in small areas but as with the solder and propane torch, it may not provide enough BTU's to braze if the wire acts too efficiently as a heat sink and removes the needed heat.

If so, a oxy-acetylene torch would be needed.


anything sound hopeful or promising so far?

Certainly no TIG here and no idea of what one would cost.
I used to have an oxy-acetylene torch years ago but it's long gone.
Maybe the MAPP system would do the job for us. It's only 4 gauge wire but I am aware of the heat sink problems.
I have experience in soldering copper pipe and electronics. I know in electronics that the soldering process is not considered as having any mechanical strength.
I know when soldering copper pipe that it's a tight fit and that's where it gets it's strength.
So I assume use an acid solder on the wires? I will assume that joining the wires is not an option with soldering and I sold provide some type of mechanical wrap on the wire for strength?
I would hate to have buy another oxy-acetylene torch setup for this amount of hobby welding as I may not get much use out of it after I am done.
I have seen some reasonable wire feed machines in the stores but I am not sure what process the use. Someone told me at one time that they were for lightweight work just like I am attempting now.

I have never heard of anybody using a wire welder (flux core) or a MIG (solid core with a shielding gas) to weld copper. The wire would have to be compatible with and meld with the copper. I do not know if such is available.

A TIG welder can be used without any filler material in many situations and scrap pieces of the wire would make excellent filler material as well.

Obviously if it is not going to be used enough to justify the cost, it is not the best idea.


part of my lack of exactness is I do not know how much physical strength is required. If soldering, you may be able to use a splice piece that laps both sections of the wire. Even taking strands from a piece of the wire and spiral wrapping or simply laying it alongside the main piece it and then soldering over the entire splice would afford some additional mechanical strength.

maybe using a copper pipe coupling for small diameter pipe would work if you could get a coupling that fits relatively snug.


as I said, brazing itself is stronger simply because the brazing rod is a harder metal than the solder is. You could utilize the spiral lap or pipe coupling in addition to this as well.


there are small systems that utilize MAPP gas and oxygen in small tanks like a propane tank. Maybe that would be of benefit to you.

http://yourhome.shoptoit.ca/ss/media/16378000/16378302.jpg

there is one other method I use (I am an electrician and deal with such things occasionally)

cadweld systems. CADWELD Electrical Grounding and Bonding (http://www.erico.com/products.asp?folderid=41)

many of the systems are designed to be used with a mold (handy with carving graphite and have a chunk laying around?). some systems come with a one time use mold as well though.

if interested, cruise around that site and look. If you have questions about cadwelding, I will try to answer.

Use Mapp Gas and brazing rods. Mapp gas is considerably hotter than regular propane. You don't actually "weld" copper, as it will melt first. You'll just heat it and braze it in place.

Ok, I will give that a try, Thanks.

OK, thanks for the information.
I just picked up a used Benzomatic Mapp set similar to what you show there for $20 at a garage sale.
I saw it on a local ad and ran over there this morning and bought it.
I then went to ACE as the local welding supply is closed and bought a few brazing rods but they were not cheap due to where I got them.
I will give this a try and see what happens but I think you are correct and this is going to work just fine.
I appears I needed a bit more heat and the MAPP with the oxygen boost should do the trick.

please keep me posted to your successes (and maybe failures:mad:)

Oh, and the structural support issue you addressed is rather light. I just want to use these wires as a small frame to support some sea shells in a waterfall arrangement in a medium sized indoor fountain that I have designed.
If this works I may spend some time in retirement making fountains as a hobby as such.
I don't care if I make any money at it or not in retirement.
It gives me something to do.
I do think I may have to move up to larger bottles of gas if I keep doing this however.

The solder with a MAPP torch would prob work fine. I didn't see if this was solid or stranded. I use solid copper ground wire to bend all sorts of hooks for hanging bird feeders and chimes and such.

To make a better mechanical connection, if it works with your design, bend the ends of the wire tightly together (like hooking 2 fingers together), then solder. You can get a very tight joint using Channel lock pliers or a small vise.

I also like the idea of using the correct size copper tubing and inserting the wire into it.

Oh, and the structural support issue you addressed is rather light. I just want to use these wires as a small frame to support some sea shells in a waterfall arrangement in a medium sized indoor fountain that I have designed.
If this works I may spend some time in retirement making fountains as a hobby as such.
I don't care if I make any money at it or not in retirement.
It gives me something to do.
I do think I may have to move up to larger bottles of gas if I keep doing this however.

don't forget me if this works and becomes profitable:thumbup::D

ultimately, if looks are of concern, the TIG would be the way to go eventually since you can simply melt the ends together thereby having only copper and no solder or braze involved.

they are fun to play with as well. I know a couple folks that have welded aluminum foil together.

Depending on how you want the finish to look you could use silver solder or sil-foss and would likely be able to braze this with a mapp fueled torch.

Click image:
http://bernzomatic.com/Portals/8/Resources/ProductImages/BZTG_TS8000ZKC_019080_slvr_sm.jpg (http://bernzomatic.com/PRODUCTS/TORCHES/PROFESSIONALTORCHES/tabid/230/Default.aspx)
Image courtesy of bernzomatic.com.

Both methods would have more strength that you need.
There is also another product called silver-brite and it is a soft solder with a small silver content for more strength and won't tarnish like straight soft solder.
Silver solder, which is actually a brazing material will have a lot of strength and your joints when the brazed area is cleaned will be bright silver.
Sil-foss is a braze that doesn't require flux and is very strong but will leave the copper discolored from the heat.
Sil-foss is mostly used in the refrigeration trade and for brazing oxygen lines and should be available at a larger welding supply store.

Moderator note:
I merged the second thread you started on this into one.

Hey, I was talking to a neighbor and he had a torch that he gave me.
It's an acetylene only Presto-lite. The hose is old and could be replaced. It came with two tips and a near empty bottle (about 50-60 cu ft I would say) of acetylene and the regulator.
What the ~~~ It was free! :D
The tank is old and I am not sure about refilling it or if it can be. We will see I guess when the gas supply houses open in the morning.
The Benzo Matic is OK and does the job but it's really tricky to adjust the $.99 cent special regulators if you can call them that. :rolleyes:
My old Lincoln gauges and regulator and torches I picked up years ago at a garage sale make this stuff look very cheap though. But that stuff is long gone along with an arc welder I had to play with building street cars :thinker: