Soldering gun for car alternator wire and other thick wire soldering work

[robsims]

Hi, i need a high power soldering gun to solder car alternator wires and other thick wires. From reviews on amazon I've seen that the Weller D550PK and D650Pk are junk. The Weller 9400PKS is better but is only 100/140 watts. if you have a good soldering gun, please let me know the brand and model. Many thanks in advance

[MikeK]

Inside the alternator or outside?  Which wires?  I used my Weller 9400PKS a few years ago to repair two internal connections on the alternator of my '90 Mazda.

[edpalmer42]

I used a precision propane torch to solder #10 AWG stranded wire to a spring clip.  The wire insulation wasn't affected at all.  I can't find that torch anywhere but the place I got it, but you should be able to get the same results with one of those small butane torches.

FYI, here's the torch I used.  It just screws on to a standard propane bottle.  https://www.princessauto.com/en/precision-burner-torch/product/PA0000140084

[robsims]

Many thanks MikeK, wires inside and outside of the alternator. Think of buying the  Weller 9400PKS too. The torch of edpalmer42 is a good option too. If someone has another option please let me know, so i can decide which way to go

[james_s]

For really heavy stuff a small propane torch is what I use too. You can get so much more heat than with an iron. Another trick I've used is heating the joint directly using a single turn of #6 wire around the core of a toroidal power transformer then touch one end of the wire to each side of the thing I'm trying to heat.

[robsims]

Thank you James_S, nice option too

[floobydust]

Soldering guns are dangerous and damage semiconductors due to the high voltage spike the transformer generates when you switch the trigger off. They are not for automotive/mechanic use really.
These (Weller) products are double-insulated (two prong) power cord so the tip is not grounded. Weller uses a solenoid-style transformer which has a lot of leakage inductance and makes quite the spark across the switch and HV spike at the tip when you switch heat down or off.

I use a butane lighter-fluid powered soldering iron like Pyropen for big stuff, there is lots of heat if I need it. There are also lots of crack pipe/soldering torches out of china that are cheaper. Or a soldering iron attachment for a propane blow torch, but hard to control the heat. If you point it down, the flame flares up which is such a hassle.

[edpalmer42]

Well, if you want a big soldering iron, you can't beat American Beauty.  They're expensive, but they're almost bulletproof.  They're available in sizes up to 500W.  That beast weighs 4.75 pounds / 2.15 Kg!

https://americanbeautytools.com/Soldering-Irons

[Ground_Loop]

Check out soldering irons used for stained glass work.  I have one that I drive with a variac for large stuff (including stained glass).

[BlackICE]

Not the best tool for the job but I'm curious how well would a JBC or Pace work with the largest size tip?

[BurningTantalum]

As this tool will probably only get very occasional use it may not be worth spending big on it. I have 2 BIRKO brand irons and a HENLEY (SOLON?) that I picked up at yard sales for a dollar/pound or two. One of the Birkos has a slash cut standard shape but large dia tip. The other 2 a large mass old-fashioned tip. They are of course not temp controlled but this matters little when soldering large connections, plates, tin boxes etc.
BT

[bdunham7]

Soldering guns suck for that.  I'm not sure how big your wires are, but if they are big or attached to something big (like in a DC generator winding) then you need something with a large metal heat sink to provide a lot of heat rapidly.  You need to get the job done quickly (to avoid damaging surrounding stuff) and thoroughly (to avoid cold joints).  A big blunt iron works for stuff like battery cables, but in your case I suspect you need something with a narrower tip.

https://www.amazon.com/HAKKO-soldering-processing-HAKKO-MATCHLESS-571/dp/B002MRR6R4

If you don't need anything that extreme, there are less expensive ~200W irons from Miyako, Weller and Hakko (Matchless) on Amazon in various configurations.  Pick one, skip the guns.

[BradC]

I have an old version of this :


Heat it up with a blow torch and away you go. Does everything from 0 AWG battery terminals through to lead flashing on the roof.

[Mechatrommer]

someone call it horse dick iron, or maybe elbow iron is the proper name? i always wanted to have this, but i dont have a use, so i only look and waiting... i can see china brand is available and cheap too

[robsims]

thanks edpalmer42, the irons are a bit on the expensive side

[CaptDon]

I still have my Weller WD250 250 watt soldering gun for big stuff. I think it is older than me. There is a newer dual heat model that is 250/320 watts. We used the newer model (available used for dirt cheap and often found at big yard sales etc.) for several decades and NEVER damaged any parts with it as far as inductive kick etc. that flooby mentioned. My neighbor who does nothing but car alternator repairs and mods (one wire conversions) as well as car, truck and tractor starter motor repairs has used his 250/320 Weller for several decades with no problems. I nicknamed my 250/320 (which my brother in law borrowed and never returned) 'The Molly Blaster'. The neighbor liked the name and calls his The Molly Blaster also!! Yes, I still own and use the older WD250 model for 10 gauge speaker wire and other big jobs. My little Weller 8100 (140watts?) which is probably as old as me is my daily work horse (along with solder wick or a solder pull-it) for big heavy MOSFET, Power Diode or Power BJT leads and again I have never trashed even a power MOSFET from 'spikes'. If I was really worried about it or experienced failures induced by the soldering gun I would simply ground the big heavy steel loop that powers the tip. By the way, the WEN soldering guns with the steel tip absolutely suck!!! I hate 'em.

[Mechatrommer]

for several decades and NEVER damaged any parts with it as far as inductive kick etc. that flooby mentioned.

i think modern iron has heating element insulated with potted ceramics or whatever, if done correctly the tip should be well isolated. i'm more worry to the floating smps wallwart used in some test equipments as they zapped few bunch of my new mosfets in one test session for free.

[james_s]

i think modern iron has heating element insulated with potted ceramics or whatever, if done correctly the tip should be well isolated. i'm more worry to the floating smps wallwart used in some test equipments as they zapped few bunch of my new mosfets in one test session for free.

He's not talking about irons, he's talking about soldering guns, which have the tip heated directly by passing current through it. I've never fried anything with one either, but I typically pull the tip away from the joint before releasing the trigger.

[Mechatrommer]

i think modern iron has heating element insulated with potted ceramics or whatever, if done correctly the tip should be well isolated. i'm more worry to the floating smps wallwart used in some test equipments as they zapped few bunch of my new mosfets in one test session for free.

He's not talking about irons, he's talking about soldering guns, which have the tip heated directly by passing current through it. I've never fried anything with one either, but I typically pull the tip away from the joint before releasing the trigger.

looks isolated too, and much safer step down transformer... (except the heat)

[james_s]

looks isolated too, and much safer step down transformer... (except the heat)

It is isolated, but you still have energy flowing through the tip, there's quite a lot of current circulating.

[Terry Bites]

Best not to solder. You just get inflexible brittle joints, not good in an automotive setting. Crimp joints are far more relaible.

[floobydust]

Weller 8200 soldering gun is what I noticed making voltage spikes at the tip during switch down/off.
I was soldering a battery powered clock and the display would flicker or it would reboot whenever I clicked the trigger.
The tip is ungrounded and there appears to be lots of capacitance between windings, so again I can't recommend using a soldering gun where semiconductors are involved.
Prove it by putting a neon lamp between the tip and earth ground, and doing a few clicks, it was blinking. Lesson learned.