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Thin copper sheet to 1/4inch copper tube

Posted: Sat Sep 28, 2019 3:00 pm
by Jmorgtig
So Im trying to make this rose
Image

But I want to weld a copper stem instead of a steel one. They are for the centerpiece on the table at my daughters wedding.

I flared the end of the tube and had fairly good luck with a 1/16 electrode at 75 amps but like people said
it takes a while to get the puddle and I controlled with a peddle but a few times a large piece of the
thin metal just burned away fast and suddenly.

Is this due to over heating. Would backing with argon on reverse side help
would pulsing help. How do you control it at times it was going great then wham blow out

Thanks for the help

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sat Sep 28, 2019 6:58 pm
by LtBadd
You said it is blowing out, is the tube sealed? If so then that's the problem, but I think maybe you mean the metal just melts away.
If you use silicon bronze filler then you can get a quick tack or short weld due to the lower melting temp of the filler.

Got any pics you can post of this setup?

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sun Sep 29, 2019 1:07 am
by Jmorgtig
Yes the material melts away is the issue . the 22 guage sheet melts first then the tube.

the tube is pinched on one end I can open it. Ill take pics of set up . what do you want to see
should you back purge tube with argon?

I just found out that not having a ground is probably causing a lot of my issues with arch wandering also not having a wind screen. Im outside.

Doe that make sense. Im getting a lot of arc wandering now. Was not as much a problem yesterday.

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sun Sep 29, 2019 7:14 am
by LtBadd
If you didn't have a ground you wouldn't be able to have an arc.

Arc wandering could be due to a long arc. What filler are you using?

A purge is not going to stop the tube from being blown away due to over heating

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sun Sep 29, 2019 8:47 pm
by Jmorgtig
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Re: Thin copper sheet to 1/4inch copper tube

Posted: Sun Sep 29, 2019 8:49 pm
by Jmorgtig
Well grounding the unit made a big difference. I was able to get good puddle formation in the copper sheet 0.026 at only 61 amps and use the foot pedal and pulsing to reduce burn out. However when I got to a edge that was lifted off the table it burned right through. If it was against the table I had better control.

I am using 12 guage electrical wire it seems to work good. started with 12 guage I think 14 will work better.

If I mount the 1/4 tubing ontop of the sheet and arc to the tubing vs the sheet it melts faster then the sheet forms a puddle.
I was moving back and forth across the tube and sheet spending more time on the sheet to get them both to melt at same time then dipping the wire filler into the puddle. I started to get it but I notice for sure if the thin sheet is in air off table vs on the table it burns through at 61 amps. so I guess maybe the table is just acting as a heat sink? when its off the table no place for heat to go? But why does the tubing which it thicker melt faster than the sheet. Could it be the same thing its standing off the table. Ill try to draw a picture or take one

OK dont make fun of these. its my second day tig welding. steel was easier , copper is tougher

Bead on sheet on table , 61 amps, 5 sec pulse 50% low pulse, 50% duty
3/32 2% lanth electron, argon 12 cfh gas lens number 9 torch

https://drive.google.com/file/d/1IQ2Cpt ... sp=sharing

First attempt fusing copper tubing to sheet metal

https://drive.google.com/file/d/1IXci2c ... sp=sharing

Warp in sheet lifted from table and while trying to get puddle in sheet burned out.

https://drive.google.com/file/d/1IYT1JE ... sp=sharing

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sun Sep 29, 2019 10:07 pm
by Olivero
I'm all about welding everything, don't get me wrong.

But for something this fine, have you considered brazing it?

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sun Sep 29, 2019 10:31 pm
by Jmorgtig
1 wouldn't there be a color difference

2. trying to learn how well tig works
and what it can do. If I got this far in a day I think with experience this should be very
Doable

Re: Thin copper sheet to 1/4inch copper tube

Posted: Mon Sep 30, 2019 12:22 am
by Radishfever
My friend this is just a guess to play around.

While looking at that last picture where the edge got melted away, I had this idea. The stem and pedals are really thin correct? Instead of lighting up directly on the thin material, could you light up directly on top of the filler metal. Kind of like lay wire except really lay tack.

If all fails, solder would be more than strong enough and easy.

Re: Thin copper sheet to 1/4inch copper tube

Posted: Mon Sep 30, 2019 9:46 am
by Olivero
It would be slightly more of a bright yellow.

But, If you insist,

TIG welding Copper is tricky because it's such a good conductor, by the time you pump heat into it, it's gone and spread so you need to pump a LOT of heat into it very fast for a short time, I've welded copper myself many times and that's the trick.

Weld it on DC, Argon, similar to how you would steel but turn the amps up higher than you would for steel, if you prolong the weld, I would expect it to warp.

Re: Thin copper sheet to 1/4inch copper tube

Posted: Mon Sep 30, 2019 6:19 pm
by LtBadd
going in hot and fast (short duration) is doable but also risky, maybe if you have some scrap pieces practice on them first. If you use silicon bronze it would be much easier, and the color, well I wouldn't describe it as "bright" yellow, but I do think it looks good with copper

Your tacks would be small, and wouldn't

they be under the flower where the stem meets it?

Re: Thin copper sheet to 1/4inch copper tube

Posted: Sat Oct 12, 2019 12:13 pm
by Jmorgtig
Thanks for all the help when I do get it to work it looks so great. copper on copper.

I find if I preheat the thick 1/4 stock first get a small puddle then intro the thin metal which heats up fast.