iDRY Vacuum Kilns

Sponsors:

Spot welding copper?

Started by Gilman, January 17, 2005, 06:56:58 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Gilman

A bit off topic, but I need an answer  :D

Anyone know if you can spot weld copper?  If so, do you need a dissimilar metal for your welding tips?
WM LT70, WM 40 Super, WM  '89 40HD
Cat throwing champion 1996, 1997, 1999. (retired)

footer


etat

I've never heard of arc welding copper. I do know it's really easy to soldier or braze.  Soldering with a hot iron will keep the heat lower and produce the least amount of distortion.  Copper likes to move when it gets hot.  A high lead type soldier will require the least amount of heat.  For a stronger bond silver soldier can be used.  Silver soldier would probably require the use of a torch rather than a iron because it takes more heat to melt the silver soldier.. When soldiering I like to use solid soldier wire and apply the flux by hand.  Acid or rosin core soldier will also work.  For a even stronger bond you could try brazing.  This would definately require a gas oxygen torch rather than a propane torch and would require more heat.

Either getting the heat right is just a little bit tricky.  Not to cold, and not too hot.  A bit of practice and you can get it just right.  

The more you work copper, or brass  the harder it gets.  Also when joining it it has to be clean.  Absolutely clean. Over work it and it gets brittle.  To soften it back up requires annealing by heating the copper and immediately cooling it with water.  

What are you trying to weld or join?
Old Age and Treachery will outperform Youth and Inexperence. The thing is, getting older is starting to be painful.

J_T

I know we got some ac repair men on here. Most time I use brand name I think is silfose  it is 15% silver and is in thin sticks last I got was 22 bucks a lb .Ad this in with Ck's and all three of us will be in the dark :D :D What you trying to do more info ??? Most time silver solder is used for dismler metals as in copper to steel joint have used it on lines up to 750psi.good luck
Jim Holloway

Gilman

I build copper top tables for the electronic test industry.  They need a table  5' x 20' with grounding flanges on three sides.  Thus, 30' of bonded copper flange to the copper table. I don't want to apply heat to the edges due to the warping problem that would ensue.
WM LT70, WM 40 Super, WM  '89 40HD
Cat throwing champion 1996, 1997, 1999. (retired)

J_T

Could you use a metal break and break the sides and have it all in one peice ???
Jim Holloway

Larry

"Electronic test industry - grounding flanges - bonded" are terms that pop up a red flag.  Caldweld on ground wires prime example.  Can you check with the buyer first and see if there are any special electrial requirements for the welding?


Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

neslrite

What gauge is the copper?
How high is the flange above the table?
Kevin
rule#1 nobody ever puts just one nail in a tree  LogRite Tools  www.logrite.com

DanG

Hey, y'all don't stop now!  I'm learning here.  I have a little project of my own that I'm thinking about.  I want to make a "once and for all!" pair of jumper cables. I bought 4 pairs of small vice-grip type pliers, and some copper lugs. My question is about brazing the lugs to the pliers. Should I braze them with brass, or is the melting temp of the brass higher than the copper? Once the lugs are bonded to the pliers, I can solder the cables into them.

I'm a rank rookie with a torch, just got my first one last month, but I did try brazing onto the vice-grips with a piece of copper wire. It seemed to bond really well and easily. Haven't tried it with the brass, yet.

Any input is appreciated. :)
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Tom

I super glued a penny to the floor one time. ;D

DanG

I thought about that, Tom, but how would I get the floor up to the vehicle to jump it off? ??? :P

Always willing to listen to new ideas. :D
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Dean Hylton

Dan, just an idea. Use a piece of thin wall steel tubing or pipe. A lot easier to weld it to the pliers. Then solder the cable in.

DanG

Thanks Dean. I did sorta look around for something in steel, but didn't spot anything real handy in the places I usually go. I'm gonna play around a bit with the copper lugs and see if'n I kin get'em to stick. If not, I'll look for something else.

The thought line is still open if anybody else has suggestions.  BTW, I posted this here to bring Gilman's thread back to the top. His project is interesting and could stand some more discussion. :)
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

MemphisLogger

I'm bringing this thread back up 'cause I was hoping it would lead to me knowing how the re-solder/braze the top on my radiator.

See, I've got this hissing leak all along the top where the core is crimped to the stamped top.

I assumed that I could just clean it up and resolder it with silver/tin solder and heat from a propane torch, but I haven't been able to find anything on the net to support this.

Does anybody know about this?
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

DanG

You can do it with acid core solder, but it's one of them things that seem's ta take practice.  I've fixed'em before with JB Weld.  That was on a plastic tank, though.
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

MemphisLogger

That's what I thought, DanG.

My soldering experience is limited to stained glass work but in doing so I've had to solder dissimilars--steel, zinc, lead and copper in the same piece sometimes and it seems that acid silver/lead does a decent job on those.

I was thinking I'd need to use a higher silver content on the radiator due to temps and pressure.

I guess I'll go ahead and take a shot at it--can't hurt since I  really don't want to pay the $175 NAPA wants for it.

  
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

WH_Conley

UrbanLogger, if this is a brass radiator that is not a crimp, it is a solder joint. I will give you my suggestion.

Take radiator out and put it in position where the old solder will run out when melted, wire brush it good first.

Gently apply heat to effected area and tap GENTLY with a small piece of wood, you will be suprised when a whole strip runs out.

Clean as good as you can with wire brush.

Find some tinning compound, sweating new solder requires too huch heat, apply tinning compound and heat it just enough to melt, it turns to a solder coat, very shiny apply new solder, doesn't need a lot of solder, again just enough heat to get a bond.

Should be done.

The downside, where new and old solder meet you will almost always have a pin hole, add a tablespoonful of fine ground black pepper to the radiator. (Honest it works)

This should hold for a while, best cure would find an old man at a radiator shop that has the jitters from snoffing too much lead and let him take the tank completely off and re-install it.

JB weld works for a band aid, and sometimes for a long time but if you ever plan on taking it to a radiator shop later on don't put it on, they will probably run you off.
Bill

Gilman

The tables:
1 to 1 1/2" flange.

0.093" thick

Can't solder due to the manufacturing process.  

Pre bending flanges are not feasible due to standard copper sheet sizes and the manufacturing process.  I'd end up with a lot of waste and have extra seams in the top.

As far as brazing, Clean, Clean and clean once more.  Emery paper, flap sanders, SS wire brush.  Then use Non electrical solder with brush on flux.  Also, don't apply the flame directly to the area being soldered.  If you do apply the flame there, the copper or brass with oxidize and you just lost your clean surface.  The flux does help remove this oxide layer though.  PRACTICE first, you'd be amazed.  Let us know how it goes.
WM LT70, WM 40 Super, WM  '89 40HD
Cat throwing champion 1996, 1997, 1999. (retired)

Murf

Maybe I missed something, maybe I'm just dumb, but why can't you just weld the flanges onto the table?

It's thin material, but if you keep the current low on thin wire it will work fine.
If you're going to break a law..... make sure it's Murphy's Law.

MSU_Keith

Regarding spot welding copper:
- It is done but requires special considerations.
- The higher the purity of the copper, the higher the electrical conductivity(which is what your looking for in this design I'm guessing), and the worse the electode pickup.
- Having water cooled electrodes is a good idea.
- Most industrial operations use tungsten or moly tips ($$$  :o).
- Might be able to get away with sandwiching the weld in between thin pieces of conductive sheet stock or tinning coating to prevent electode pickup but this might make for some ugly looking welds.
- You might want to consider ordering the RWMA manual on resistance welding of copper:
https://secure.proaccess.net/rwma/order/
- Another possibility is to consider brazing with copper-phos (AWS official designation BCuP) filler metal - this does not require flux and is alot less dependent on surface prep.

Be carefully using soldering and brazing interchangably; they are not the same and the filler metals are very different.  Brazing filler metals have a melting point of >840F, soldering uses filler metals that have a much lower melting point and result in joints that are not as strong.

For a crimped joint a quick and easy way to repair is to use foil braze.  Just peel back the joint under some heat, clean it out, then line the crimp with some foil braze, crimp back together and heat to the recommended temp under some clamp pressure - it will look like a pro did it.  Unfortunately foil braze is not available at Home Depot and the minimum order from a manufacturer is probably enough for 1000 radiators :(

DanG

Boy, we got off track on this one, didn't we. Guess that was my fault. :-[  I really just wanted to bring the thread to the top to troll for more answers.

Look's like we found someone with the right knowledge to help Gilman out, though. Welcome aboard, Keith! 8)  Could ya sorta draw a line between the test bench answers and the radiator soldering info?  Wouldn't want these guys, including myself to get confused.  In the phone business, we used a lot of copper busses for transmitting power to the switching equipment. All of the connections in that stuff were either clamped or bolted together using a conductive paste between to prevent corrosion. But, that was in a low voltage/high current environment(48-52vdc, 1000+amps).  I'm sure the conductivity requirements for Gilman's project are higher than our's was.  Keith, I hope you'll come back with more specific info.  My interest is piqued, as, I'm sure, Gilman's. :)
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Fla._Deadheader


  DanG, try Silver Solder on the Pliers. Scratch 'em up a little. Use the torch and the copper will get red hot. Solder will melt before the Copper, AND, be a very strong connection.

  That Radiator soldering can be tricky. Shops dip 'em in an acid bath and clean 'em real good before soldering. I believe they use soft solder. It comes in a roll. CLEAN is the key word in Radiators. Uaually, I tear out the rubber seal and take the pressure off the cooling system. I lkow, I lkow, the experts say ya HAFTA have pressure. I just don't believe it. ::)

  Never had anything go bad doin it. Mostly, the pressure is so the water won't boil at 205°. Save money on thinner Radiators, don'tcha know.  ::) ;D ;D ;D
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

DanG

Thanks H.  I hadn't thought about silver solder. DUH! ???

I never bothered about ripping the rubber outta tha cap, just leave it at "half-latch". ;D :D :D :D
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Fla._Deadheader


  Sometimes the system will still build pressure at "half-latch".

  My Dad was a Mechanic for the town we grew up in. One day, a driver said the truck was makin a funny sound,(Ford) ::)
  He went out and it was "whistling". It was makin steam, so, he gets a rag and turns the cap to ½ way. BAM, the top of the Radiator collapses tight on top of the core. :o :o  Never heard of it before or since. ::) ::)
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

DanG

Sounds like he let out the last little bit of steam there was. :D :D  It has been my experience, and I have(and still do)driven a LOT of junk, that a fella that loosen's the cap to get by for a little while tends to watch the temp guage pretty closely. If he don't, he deserves a nice long hike on a balmy day. ;D :D :D  A coupla milk jugs of water will save some shoe leather, too.
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Fla._Deadheader


  That's what them gauges are put there for. ::) ;D ;D ;D

  Never have walked, yet.  ;D :D :D
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

BW_Williams

Gilman, have you tried TIG?  I served a 7 year term as a motor rewinder and we Tigged all our large copper connections.
Urban, no radiator shops in Memphis?  Good luck, BWW
Support your local Volunteer Fire Dept.  (not by accident)
Support your local Ski Patrol (by snowboarding:)
Mayor of Millerdale, Washington, USA (by God)!

MSU_Keith

DanG - Why wouldn't I come back, I'm hooked on the FF - hope my marriage doesn't suffer   ::)

Good point about current requirements - I assumed the contact area (40 feet) of the flange to the top of the table would be enough to handle it.  It would be interesting to see what this table is used for.

A series of little puddle TIG's through holes pierced on the flange would be a good idea - act just like a spot weld and keep the heat to minimum preserving flatness of top.

Paschale

Hey there, MSU_Keith...GO SPARTANS!!!!   8)

I'm a Spartan myself...spent eight years there, and grew up in Lansing, so I'm definitely a FAN of THE university of Michigan.  (Which, btw, Shotgun, isn't MTU).   ;)

Dan
Y'all can pronounce it "puh-SKOLLY"

MemphisLogger

BW,

Fixin' my own stuff is a matter of principle. 8)

. . .especially since the radiator developed the leak due to my own indescretion involving 2 magnums of champaign  :-[
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

Tom




How can you afford to run that stuff in your radiator? :)

MemphisLogger

Only the best for my baby  ;) ;D :D
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

Gilman

I thought this subject would have been burried within a couple days. :D

Thanks all for the ideas.  Looks like I'll try TIG first on some scrap I have.  Should I use 2% thoriated or pure tungsten?

WM LT70, WM 40 Super, WM  '89 40HD
Cat throwing champion 1996, 1997, 1999. (retired)

BW_Williams

Gilman, if I recall correctly, tungsten, round tip?  But  alot of water has gone over the dam since then :D I do recall once you were setup, it was real pretty.
Urban, no more drinkin' and logging  :D
Support your local Volunteer Fire Dept.  (not by accident)
Support your local Ski Patrol (by snowboarding:)
Mayor of Millerdale, Washington, USA (by God)!

MemphisLogger

Just to keep this thread on top, have any of y'a;l ever tried propane roasted boloney sandwichs with grits and sparkling grape juice?  :D
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

Gilman

Urban,
I assume you consume those in the reverse order?

Lots and lots of sparkling grape juice and then a "great" idea hits you to cook something fancy for dinner?
WM LT70, WM 40 Super, WM  '89 40HD
Cat throwing champion 1996, 1997, 1999. (retired)

MemphisLogger

Nah, more like ya been sweatin' pipes and dancin' with the  recluse under some coal-dusty ol' house and you find a case of sparkly grapes in the shed and ya figure you should wash off some o' that dust and then ya get to thinkin' 'bout eatin' somethin' and all ya got is this mayonaise, boloney and cheese sandwich (on whole wheat bread, of course) and then ya think hey, I gotta portable propane BBQ right here in my hand and ya light it up and toast that baloney all bubbly and crisp on the edges but the sandwich don't help any with those 2 magnums you tossed back like a showoff and instead ya decide to quit early and go for a ride in your truck down in the bottoms even though its been raining for like two weeks and promptly get stuck up to yer rockers in . . .

MISSISSIPPI MUD!


Dear Lord, I am ever thankful I have a wench, I mean winch, to bail me outta my troubles.  

 ;D
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

etat

 :D :D :D :D 8) 8) 8) 8)


I mostly didn't have a torch with me.  I have however wrapped hotdogs  up in aluminum foil and throwed em on top of the manifold and then go ride around a minute and let er warm up though! ;D
Old Age and Treachery will outperform Youth and Inexperence. The thing is, getting older is starting to be painful.

MemphisLogger

Whats' the aluminum for?  :D
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

Gilman

WM LT70, WM 40 Super, WM  '89 40HD
Cat throwing champion 1996, 1997, 1999. (retired)

Avalancher

As Jeff pointed out in another thread, one way or another most of these discussions end coming around to something to eat.
We need to open a recipe thread I guess. :D

Norm

QuoteWhats' the aluminum for?  :D


Jeez Scott don't you know anything...it keeps the grease off the manifold. ;D


MemphisLogger

Well gosh darn it, bein' that it's cast iron I thought you were SUPPOSED to season it!  :-[  ;D :D
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

Furby

Christmas dinner for me a couple of years ago was a can of chicken and dumplings, warmed on the manifold, just outside Yosemite N.P. ;)

MemphisLogger

Furby,

I'd take a can of luke warm chicken n' dumplin's in Yosemite over the fanciest fat steak in the city any day of the year--EVEN Christmas.

I imagine that was a very spiritually FULLfilling if not tummy filling supper.  ;)
Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

DanG

Much as I like to be disagreeable, I'll have ta go with ya on this one, Scott.  Saltines with honey and dill pickles would taste good at Yosemite! ;D
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

MemphisLogger

I worked at the gallery there for 2 summers. On my days off I'd go on solo hikes (or guide a cute visitor or 2).  8)

My favorite light pack was a summer sausage, a block of waxed WIsconsin, a loaf of hard bread and a six pack of Sierra Nevada.  :)

Hmmm.....  ;)

Scott Banbury, Urban logger since 2002--Custom Woodworker since 1990. Running a Woodmizer LT-30, a flock of Huskies and a herd of Toy 4x4s Midtown Logging and Lumber Company at www.scottbanbury.com

Furby

How'd ya know it was "luke warm"??? ;D ;)
Yeah I have to admit it was worth it! Spending Christmas day there, I really didn't feel like I was missing anything.

Thank You Sponsors!