Joining copper sheet

FWIW:

If there are more than one joint I would avoid soft solder: The heating of the piece becomes critical and I have nearly lost my marbles while soldering one joint with the other joints coming apart simultaneously. There may be other issues with exposing soft-solder joints to weather.

I have had good success silver soldering using MAPP gas only with a Bernzomatic torch. I use the lowest melting point alloy.

I've assembled durable 3D shapes in copper by folding a flange over for mechanical strength before soldering.

Depending on his soldering experience an iron may be easier to control than a flame. Once for fun I duplicated the TIG pattern of overlapping circles on the soldered seams around some RF filter cans by moving the iron back and forth and watching the puddle.

It's all practice. I have been at it so long I can splice 0.015" solder end to end into rings with an iron. Try it!

jsw

I'd tin the entire inside faces with solder, then sweat the edges together.

...

Wouldn't silver solder have the same problem with previous joints coming undone? Ideally you would have a progression of solders with decreasing melting points.

Well, they use soft solder on copper gutters, or don't they?

Thanks, Bob

Not in my experience. The heat conduction through copper is such that it is not difficult to achieve the 200-odd degC needed to melt the soft solder quite a distance away from the joint you are working on. It is much harder to do the same for a melting point of 600-odd degC. The heat tends to dissipate before it gets there unless the joints are *very* close together.

True, I think.

Just doubled thickness:

| | | | | | |||| ||||

or having overlapping edges:

| | | | | | ------ | ''''''''

or seams: | | |____ | ____| | | _____| |_____

How did you handle the problem of previous joints coming undone when soldering the next?

What size iron are we talking about here? I have a old iron that's just a 1 lb hunk of copper & is heated over a torch. Never used it - how would it compare to 'lectric?

I think that I'll need a little more practice first .

Thanks, Bob

Good point. That might help with something that he's worried about: keeping solder from where he doesn't want it. I.e., on the outside surfaces.

Thanks, Bob

OK, I can see that. But, talking about heat being dissipated, is it hard to get large pieces of copper hot enough for silver solder? Oh, I guess MAPP would do a much better job than propane.

Thanks again, Bob

Bob Engelhardt fired this volley in news: snipped-for-privacy@news2.newsguy.com:

Bob, just as they say in the electronics trade, "Solder ain't glue".

Soft solder has virtually no tensile strenght, but is fairly strong in sheer. Hard solders are stronger, but still aren't intended to hold things together until after they cool completely; they are pretty weak when heated near-melting, but not quite.

Solder shouldn't provide the mechanical attachment; it strenghtens the joint, keeps it from moving after soldering, and keeps it sealed to the weather. The joint itself should be _mechanical_ in nature, and at least strongly-enough joined so that it will endure the forces of handing and fixturing during the soldering.

LLoyd

Bob Engelhardt fired this volley in news: snipped-for-privacy@news2.newsguy.com:

Properly applied, the solder will form a meniscus between parts, and won't flow over the edges unless you apply too much.

You could apply a masking substance where you don't want it to migrate. I don't have any brand names at the tip of my tongue, but there are several for just that purpose. You might find them at a well-equipped art supplier.

Also, soft solder planes off any surface pretty easily with just a sharp knife. You could clean up any buggers fairly easily, then re- buff or re-texture the surface.

LLoyd

Propane is plenty hot enough for most silver solder on copper. Have to use plenty of flux to keep the copper from oxidizing while it is hot. The biggest problem with heating for silver solder is keeping the copper from walking away from the heat. Any sheet form will warp and twist from uneven heating. Need to clamp it quite well.

The lower heat from leaded solder will not warp near as much. Again, lots of flux!

Paul

snipped-for-privacy@news2.newsguy.com:

Jus this afternoon, I was out in the garden and noticed that my wife had ponded some nails into a post and wrapped wire around them for a vine to climb on. I asked her about it, and she said she had done this a couple of years ago, with a roll of wire on my workbench.

It turns out that the wire was .020" flux core solder, and had been out in the elements for a couple of years, holding up a clematis with no ill effects. Given that bit of empirical data, I wouldn't hesitate to soft-solder a weathervane.

Also, if you apply the correct amount of heat, you really don't need to worry about adjacent joints. I, too, have amused myself by splicing solder. It's really not hard once you get the touch. .

One commonly used masking substance (often called "anti-flux") is yellow ocher. You can get it from any of the jewelry supply places, on line or elsewhere. Jewelers use it for just that, to keep solders from flowing where you don't want them to flow. Just one such is here:

For small stuff, I often use white-out, the correction fluid stuff. Works great. Just beware that some formulations (the non water based ones)of it are flammable and it makes nasty smelly and probably somewhat hazardous fumes when you first heat it. Take appropriate precautions and have good ventilation, etc.

As an aside, get yourself of a few of the jewelers supply catalogs. They have a whole world of cool neat-O tools, supplies, chemicals and gadgets, sure to fascinate most anyone who spends much time here...

-Al A.

rangerssuck fired this volley in news:53f6b4ee-2729-4410-a26f-3ee0951c7a54 @k26g2000vbp.googlegroups.com:

hesitate

There's no question that soft solder will withstand the elements, but I'll bet dollars to doughnuts that the 20-thou. solder was not "holding up a clematis". Rather, it provided a growth path along which the clematis vines found their own purchases along the way. 60-

(pretty stuff, that, especially on a walk-under arbor)

LLoyd

Propane is plenty hot enough, but large copper pieces do require thinking. I like to use IFB ( insulating firebrick ) to surround the work. If it is really big two or more hand held propane torches may be required. If it is not too big, I will first heat the part away from where I want to silver braze. So that that part is not sucking heat away from where I need the heat.

You might consider SilFos. It is copper with some silver ( up to

=20 Dan

Go to a hardware store or a big box Home depot etc - buy some flat looking bronze - it is for plumbing - that of the air conditioning brazing. It is easily done with MAPP.

Mart> A friend is making a copper weather vane. Basically a silhouette, but

======== I would suggest that this is not a new product/project as similar weather vanes have been around for 200 years or more.

Why not check and see how the people did it in the past as their techniques must have worked and lasted.

My guess would be a high tin soft solder and an organic flux with a big copper soldering iron. Most likely there were considerable mechanical joints/tabs/folds/rivets [and possible some wire lacing or stitching] and the solder was just used to seal things.

for some current production see

Unka' George [George McDuffee]

------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).

F. George McDuffee fired this volley in news: snipped-for-privacy@4ax.com:

Um, Unk? When you make a post like that, you should suppress your sig line!

LLoyd

This doesn't mean what it used to. Dunkin Donuts at the Florida Turnpike service plazas now charges $1 per donut. Parity has finally arrived.