Solder for alternator rectifiers

[Ostinato]

I am replacing a rectifier in a Balmar series 6 alternator. I have some high temp solder but am having trouble getting enough heat out of my soldering gun to do an effective job soldering the rectifier to the coil. What risk an I running to solder using solder for electronics etc.? (Crimping alone is not a good option with this alternator.)

[Emmalina]

If your Alternator gets that hot it will melt normal 60/40 solder I would worry ! Thats in excess of 188Dg Centigrade or 361 F

[Frankly]

95/5 solder (now required for plumbing in the US) is a higher temp solder but you will have to get some rosin paste. I have used this with a small soldering iron before, but be careful to not overheat the diodes.

[hellosailor]

If your soldering gun can't get hot enough, there's a chance that it will still get hot enough to overheat and destroy the electronics without melting the solder.

So you go to an alternator shop, or buy a proper soldering iron. Which, after all, should last you 20-50 years anyhow.

[Snowpetrel]

Yeah I had a lot of trouble soldering one on many years ago. I cant remember all the details but. Ended up having to use a big old school soldering iron that I heated up near red hot on the stove. This worked ok, but I had to redo it a few times.

Edit to add: I was about as far from an alternator shop as I could get, otherwise I would have sent it in to the specialists. I had nothing to loose and everything to gain by giving it a go myself.

[Diesel Bill]

Use an alligator clip or needle nose pliers as a heat sink between the diode and solder joint
to protect the diode.

[Cadence]

Originally Posted by Ostinato

I am replacing a rectifier in a Balmar series 6 alternator. I have some high temp solder but am having trouble getting enough heat out of my soldering gun to do an effective job soldering the rectifier to the coil. What risk an I running to solder using solder for electronics etc.? (Crimping alone is not a good option with this alternator.)

Remember to heat sync your rectifier no matter what you end up with for solder. insure it isn't acid core solder.

[Compass790]

I'm no electronics expert but here's my experience. I had to cut stator wires off diode bridge to test stator & I soldered them back on with ordinary solder. Only done about 30 hrs on alternator since ( Bosch 55amp ) but it gets pretty hot when we run motor in the morning when batteries are down to 12v & it's pumping about 40 amps in.I used a lump of steel bar heated up on gas stove for my soldering iron. I too wondered if it would survive the heat but so far so good. Let us know what you end up doing please.

[Char99]

Originally Posted by Cadence

Remember to heat sync your rectifier no matter what you end up with for solder. insure it isn't acid core solder.

If you are using a soldering Gun, you might want to tighten the nuts that hold the tip in the two barrels that come out form the handle. Just a half turn on the nut will make the iron heat up hotter. I find after the gun sits for a year or two this really helps. Learned in this in US Navy Electronics school in the early 60's

[Ostinato]

The issue of how hot the alternator runs at is important obviously. I have a temperature sensor on it (MC-TS-A) that cuts in at 225 degrees F. This reduces the output to 50%. That helps but doesn't say how hot the alternator ultimately gets.

Since I am not running a tach off it so I will eliminate those wires which should help the crimping process. Where I am now at (Carloforte Saridinia) there are no soldering irons available so that is not an option. I have tried retightening the retaining nuts on the soldering gun. As a last resort I have thought of seizing the connection with SS wire to help make the connection less likely to separate. Any thoughts on that?

[Compass790]

Cant you get a bit of steel bar to heat up on your stove to use as an iron? I think wrapping ss wire around it is a good idea but you could equally use copper. If you have any damaged relays the coil inside has fine wire that you could wrap many times around easily. I sometimes use that technique to hold wires together prior to soldering as I have shakey hands.

[hellosailor]

What compass said. Wherever you are, you can find a piece of steel rebar or lay your hands on a big 1" wide masonry chisel or pry bar, so you don't have to hammer the end down. Then beg or buy a welding torch, mapp-gas torch, propane torch, whatever you can that gets much hotter than a stove. In the worst case, buy a bag of charcoal and pile it up somewhere, set it on fire. Heat up the chisel or rebar patiently until it is glowing red hot. (Get two of them if you want to let one heat and swap it out with the one you are using.)

That's going to take and hold enough heat to melt any solder on any joint, including plumbing pipe.

Since the alternator is somewhat valuable to you, you might want to practice on some scrap copper pipe or other junk, just to make sure you get the important job right.

[Cadence]

Originally Posted by hellosailor

What compass said. Wherever you are, you can find a piece of steel rebar or lay your hands on a big 1" wide masonry chisel or pry bar, so you don't have to hammer the end down. Then beg or buy a welding torch, mapp-gas torch, propane torch, whatever you can that gets much hotter than a stove. In the worst case, buy a bag of charcoal and pile it up somewhere, set it on fire. Heat up the chisel or rebar patiently until it is glowing red hot. (Get two of them if you want to let one heat and swap it out with the one you are using.)

That's going to take and hold enough heat to melt any solder on any joint, including plumbing pipe.

Since the alternator is somewhat valuable to you, you might want to practice on some scrap copper pipe or other junk, just to make sure you get the important job right.

Boy that is old school. The irons had massive ends that went into the forge.
I learned that circa 59. Surely there is a better way today. Getting that much heat close to a diode is going to wipe it out.

[hellosailor]

Cadence, the OP already said there are no modern tools available in his location. Without questioning that, and given his alternative of bailing wire, what better way to you think there is? Putting a plumber's torch on a diode could wipe it out, sure, but a hot iron on the metal that needs to be heated is about the only other way I know to do the job.

[Cadence]

Originally Posted by hellosailor

Cadence, the OP already said there are no modern tools available in his location. Without questioning that, and given his alternative of bailing wire, what better way to you think there is? Putting a plumber's torch on a diode could wipe it out, sure, but a hot iron on the metal that needs to be heated is about the only other way I know to do the job.

I guess I missed no modern tools available. I wouldn't be trying to put in diodes since they are somewhat modern? He might get by with anything as long as he heat syncs to dissipate the heat

I wish him the best.