Heavy Duty Soldering

Hi, In the past I've used a soldering gun with the tip cut off and a ~1/4 " gap between the electrodes. Then touched the electrodes across the workpiece firmly and applied power. Can solder a 1 oz piece of steel plate in about 15 seconds. Sort of like a mini spot welder. Works great for rechargable fixes. It might be a bit small for that big copper plate but there are bigger guns and you get the idea. Unfortunately those big irons are great for this kind of stuff, thats why roofing guys still use them. Richard

I posted this awhile back but haven't seen it appear so...

If you aren't likely to do much on this scale in the future you could try what the did years ago - make one from a lump of copper and heat in a gas ring.

Tim, you would be pleasantly surprised. GG

I've used a soldering iron with the tip cut off and a 1/4" gap between the electrodes. This was originally an attempt at a mini spot welder but worked well for soldering NiCads for renovating battery packs. It might be small for your application but maybe you could find a really big gun. It can't be used on parts that are sensitive to current. BTW those big irons are still a good bet . Guys putting in copper roofs and gutters still use them. Richard

Good question, It's an inherited board so I had to go back to the gerbers to check. The answer is no (another thing to look at changing on a board revision). Also there are four 3 oz Cu planes sitting atop one another in the board stack. Granted FR4 is an insulator but that's going to have some effect.

Robert

My bigger problem may be finding a gas ring :). My last resort though is to heat up the bar with a torch.

Robert

By what?

Robert

Hmm, essentially turn the busbar into a soldering tip. I might play with this just to see what it will do.

BTW Richard, Your replies appear to repeat themselves multiple times.

Robert

Weller Tempmatic 150 Watt with thermostatic controlled tip.

the thermostadt contol is the key, it provides feedback, the more heat you take out the more it puts out to keep the temperature at 700 deg C

on page 17 here

and other places

Mark

There is no replacement for displacement :))

Keeping the tip temperature constant does NOT help soldering big objects. The problem is a big copper bar not only does conduct heat, it also dissipates it. There is ambient air and lot of other stuff that makes the temperature drop along the bar as you go farther from that thermocontrolled tip. And keeping a point at the bar at a constant temperature does not help, it makes things worse.

The only way to do such a heavy duty soldering is to use a proper soldering iron. With a powerful constant heater and massive copper tip. Solder guns are NOT suitable for such a job. If a job requires a sledgehammer there is no way to replace it with a small jeweler's hammer no matter how technically sophisticated it is...

Don't waste your efforts, use a bigger hammer :))

That's the way I've often done it in the past. In this case though it's an inherited design and would need an extensive re-design for that to work.

Robert

Still not enough room. I've just got a little more than enough room for the ~1.5 mm Sq pins of the Bus Bar, think of it as a rather large SIP.

Of course with self threading screws there also comes the worry of metal fragments shorting out the rest of the circuit. Thread forming rather than thread cutting helps on that.

For anyone who's still following along at this point I determined that two irons together (well an iron and a gun) work quite effectively at flowing the solder without overheating the rest of the board so I expect that a large iron will as well. Three handed soldering is a bit beyond my dexterity so if I need to do any before I get the larger iron I'll be reduced to building up cold solder balls around the joint and then applying the two heat sources at once.

I quickly tried the Weller with snipped tip forming a gap but without much effect.

I'll be getting a large iron and keeping my eyes open for a cheap solder pot/wave.

Robert

Nuts and bolts ?

Rene

There are selfthreading metal screws that can just be tightened.... Possibly better than heating square inches of copper.

Rene