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MG MGB Technical - Soldering advice please!

I'm attaching some new "old school" connectors on the BGT; have a nice new set of male terminals and connectors - but here's the rub: how, and with what equipment, do I get a nice solid connection when fixing the wire to this type of terminal? - I can tin the end of the wire, and maybe I should just put plenty of solder on the wire, insert it into the terminal and then re-heat to melt the solder inside the connector?
Your experience and advice gratefully received. We never stop learning! regards, John.


J P Hall

Soldering iron is best with multi-core (fluxed centre core), soft solder used for electronic soldering. Don't use plumbing solder or flux. Grip the wire lightly in a vice or similar to act as a heat sink to prevent burning the wire insulation. Tinning the wire first is OK but not necessary and often leads to the wire being oversize for the bullet.
Clean with scotchbrite if there is any suggestion of oxide on either the wire or bullet.
Also remember BOTH halves of any soldered joint, have to be at solder melting point to give a good solid and electrically conductive connector.
Assemble the joint with a good protrusion of wire, apply the iron to the bullet and wire together and keep testing the solder on the bullet until it melts and flows freely.
Allan Reeling

John

The secret to soldering is cleanliness. Your bullet connector looks new so you shouldn’t have a problem there, it’s then personal preference which way you tackle it. I would suggest a good multicore 60/40 lead solder. Don’t use lead free solder and DON’T use plumbers flux.

You can tin the wire beforehand if you want but you may find it difficult to get the wire into the connector if there’s too much solder on it, you can also tin the inside of the connector if you want and just tap it on the bench or blow it while the solder is molten to get rid of excess.

The easiest way is ensure everything is clean put the connector on the wire, heat the connector (with a reasonable size iron of about 25W or more) and feed the solder in from the end. It’ll wick its way down the wire into the connector, once it’s cool just trim off the any excess wire from the end of the connector. Don’t feed too much solder into the wire as it will wick its way back up the cable making the cable inflexible and prone to fracture.

Bob
R.A Davis

Really clear and helpful advice, Allan and Bob - I'll have a crack at it tomorrow and report back. Thanks as ever. John.
J P Hall

Progress! - I remembered a Christmas present I'd forgotten my son (1 of 3) bought me - a soldering iron-cum-blowtorch. Because the wires that need bullet terminals are already installed in the engine bay/ grille area (headlights), I had a couple of practise goes on the bench to learn how much heat was enough. Photo 1 shows the first 2 messy attempts. By the 4th try, I was able to heat the bullet in the engine bay with the blowtorch on low, not damage the insulation, and get a very strong connection inside the bullet. Heatshrink finished off the job. Not to professional standards, but I'm confident the power supply to the lights will be better than those crappy crimp connectors. Regards, John.


J P Hall

... 4th go not too bad (the 3 with the red heatshrink).


J P Hall

... and here is the amazing soldering iron/blowtorch.


J P Hall

Good job. Test each one for continuity. Just in case

Cheers

Gary
79 MGB
gary hansen

John

Glad you’ve managed to get this done, I like the second picture (wires in the engine bay), so it really is true about things being upside down in Australia.

Bob
R.A Davis

John the type of connectors you are using are the crimp type which need a special type of crimping tool, yes you can solder them on,but they are best crimped on,soldering these connectors on takes a bit of practice, doing it on the bench is the easy bit, soldering them upside down behind the dash standing on your head is a different ball game, buy yourself a
crimping tool,
andy tilney

"John the type of connectors you are using are the crimp type".
Beg to differ, they are brass, intended for soldering. The crimp bullets are made from thinner gauge, usually plated, brass. Anyway I would always solder. I have a crimping tool which you have to use on uninsulated spades and eyes, but I I still always solder as well. Hate the sight of insulated crimps!
Allan Reeling

Ha! Bob - quite right, I forgot to rotate the photo. PS - I waved my British passport hugely this weekend having watched the Wallabies get flogged again. Also enjoying the Euro 2016, and the highlight of the sporting calendar is just around the corner ... the green grass of South West 19, down the road from my old watering hole, the Dog and Fox.Regards, John.
J P Hall

Allan a bullet crimping tool is like this, it is not the same one as you crimp uninsulated spades and eyes with, take another look at picture of that brass bullet and in particular the width of the groove, narrow groove solder type wide groove crimp type,


andy tilney

Andy, the tool on the left - is it a special ratcheted crimper, made for the old-school brass bullets? I tried crimping one (for fun) with my mole wrench ("Vise grips") and couldn't squash it. John.
J P Hall

Hi guys,


Get a proper crimping tool for uninsulated terminals.

I use one made by Wurth, had it for years.It's also alot quicker and neater than soldered joints.


If you do go the soldering route, do use a decent size iron. So many tell me they can't solder and produce a tiny 15 or 25 watt iron, which are just not man enough for automotive work.

Get a decent quality 75 or 80 watt one, the Weller ones are good.
SR Smith 1

I've still have the soldering iron, that I purchased in '62, at the age of 12. The head of it is as big as my thumb! It takes about five minutes to reach operating temperature, but when it does, it can heat up a fitting almost instantly and make the job so much easier. Last Summer, I had my '67 B out on some unforgiving roads. I hit a large hole and lost power to one of my original horns afterwards. The broken connection on the horn was huge, but after only a few seconds with my ancient soldering iron, the horn worked as good as new and still does. RAY
rjm RAY

Yes that's right, I have been crimping bullets with it for over 40 years, never made a bad connection with it in all that time,
andy tilney

Interesting Andy, thanks for that, but will still solder.........Tin and Lead are in my DNA!!
Allan Reeling

OE bullets *are* crimped just behind the head, and not soldered, using a different tool to the one that is used to crimp spades. However like Allan I always solder those bullets ... and solder spades after crimping!
paulh4

I agree with SR you need a decent sized iron, see picture, just kidding I use a 100W Weller


R.A Davis

That soldering iron above isn't that much different than the one that I've owned since '62. The only real difference is that mine has a cord. RAY
rjm RAY

Well, some old style bullet connecter controversy. Crimp the bullet at the wire end? Who left out about soldering the end of wire going into bullet first? I imagine theres some bullet type connectors made for crimping, and some made for not crimping. If you melting the wire insulation you are not keeping the flame aimed at the brass bullet or using too hot flame.
H Waldrop

Insulation damage is caused by using an iron of too low a wattage, so having to leave it on a long time to get the solder to flow, or leaving a correct wattage iron on too long once the solder has flowed. Generally the hotter the better (within limits!) for the shortest time.

I don't know about tinning the wire before crimping, unless you are going to solder afterwards as well. The solder has bulk but is soft, and may deform over time leaving a loose joint.

Who would have thought such a simple process could lead to so many opinions ...

Oh yes. Unlike James May, never carry the solder to the joint on the iron. Iron and solder should be applied together. Maybe that's why he said he hates soldering.
paulh4

Quite right, Paul - as I said in my opening post: "we never stop learning" ... provided we are open to instruction. I have found it enormously helpful to read others' opinions and experiences, and once again the advice given on this BBS has enabled me to proceed with more confidence. As some of you know, I live in a part of the world where there is very little help available locally ... and in any event, much of the enjoyment is to perform as much of the restoration work myself as possible.
So in this case, it's "job done" and we move on to the next task. In about another 20 years, I hope to be able to actually provide advice to others, instead of asking for help all the time! Regards, John.
J P Hall

John,
As my Grandad, an engineer, often quoted to me, bear in mind he was from Accrington, "them as knows all, knows nowt". The translation being, if you keep saying "I KNOW", nobody tells you anything, ergo you never learn!!
Allan Reeling

... a very wise man, that Mr Reeling senior. He also passed on to his grandson a willingness to share his knowledge. Knowledge kept is knowledge wasted. Enough philosophy - time for bed! John.
J P Hall

Interestingly new car wiring harnesses are all crimped not soldered. I am advised by a wiring harness manufacturer that aircraft wiring harnesses are also crimped - supposedly less likely to corrode, break due to work hardening, or have a dry joint.
Mike
Mike Ellsmore

The GPO abandoned soldering for wrapped joints on bulk cable terminations in the 60s. Although that was primarily for reasons of cost as each termination was cut, stripped and wrapped in one operation with a tool based on a drill, in a fraction of the time needed for hand termination and soldering.

From what I've seen MGB harnesses had spot-welded spades and crimped bullets, so soldering was abandoned by Rists by the 70s at least. However AFAIK electronic assemblies still have the components soldered into circuit boards. I can remember someone telling me in the 70s that Rists were developing an automotive system that used just a handful of wires running round the whole car, with electronic modules at each component and a central CPU to switch them on and off as needed. While cars are now stuffed with electronics the harnesses have just got bigger.
paulh4

Mike

I used to work for Plessey Military Comms and they crimped connectors for the same reason.

Paul

It’s a CAN (Controller Area Network) bus system, widely used in modern vehicles

https://en.wikipedia.org/wiki/CAN_bus

https://www.linkedin.com/pulse/automotive-can-bus-system-explained-kiril-mucevski

Bob
R.A Davis

Hi,


CAN has made modern vehicles less burdened with wiring. I worked for Porsche in the 80's and the main loom on someting like 928 was huge thick item which weighed a ton!



Current vehicles are designed to be as light as possible, this is why so many systems are ECU controlled by local modules linked by 2 tiny CAN wires.


SR Smith 1

May have replaced some wires between complex electronic modules, but from what I've seen recently (McLaren video, Land Rover factory tour) the harnesses are still significantly thicker and more complex than for our MGBs.
paulh4

This thread was discussed between 18/06/2016 and 25/06/2016

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