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Soldering

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Happy new year guy's and gals,

After soldering 2 wires together and before applying heat shrink would it be OK to apply a small amount of areldite on the soldered joint to increase the water proofing ?

Thanks

Jake.

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John,

Araldite and other epoxy adhesives are great, except when it comes to thermoplastics, and some other commonly found materials including polyethylene and polypropylene. In other words, they don't stick very well. Wire insulation and heat shrink come into these categories.

If you feel the need further to protect the joint, then better to use a silicone mastic which is very waterproof and has the advantage that it is peelable should you ever need to get back to it.

Although I don't obey this rule myself (and I should), I have been told that in any situation where vibration is likely [on a Norton?], soldering should not be used as it makes the surrounding area brittle and more likely to break. Acceptable techniques include crimping and wire wrapping. I believe I am right in saying that all aircraft wiring connections are made by one or another of these methods.

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Hi Chris, never thought about the vibration factor, it certainly makes sense to crimp the wires instead.

Thank you for the Advice Sir.

Yours Aye

Jake.

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Hi John,

just to add my 2 cents (pence?) worth, I like to add a dab of dielectric grease to my electrical connectors if crimping, and I also use it anywhere I am connecting a wire connection to ground (earth), or any other connection (bullets, screw terminals, etc). It is a special grease used on electrical connections to prevent moisture and corrosion. I buy mine at my electrical supplier, but most automotive parts stores carry it as well.

But then again, I have been told I am the king of overkill :)

Skip Brolund

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Clear silicone sealant is very good at insulating HT voltages -up to 100,000 Volts that I know of. My old colour telly with CRT was repaired by a very knowledgable TV shop usingsilicone when the HT broke down and the telly made a loud cracking sound! Flash, bang wallop at the back of it!

Re: soldering - here's me thinking I was going to solder all my newbrass-nippled cables! Not a good idea then?

Cheers, Lionel

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Hi all,

1) soldering DOES NOT make the wires brittle unless you use a flame as the normal electric iron does not get hot enough to anneal the metal. Modern lead free solder is in a word...crap and has a habit of failing but I'm sure most of us have the old stuff somewhere!

2) crimping is fairly useless unless you have the right tools and even then it is damn near impossible to get the connector tight enough. I have a tool that is over £300 new (boot sale find)for doing these and it just doesn't do them tight enough.

Solder and heatshrink are the best option perhaps with the addition of a silicone sealant if you feel the need for waterproofing.

Jim

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Call me old school if you like, but I am still a fan of Lucas bullet connectors for joining wires. I have the correct tool to crimp the bullets on to the wires leaving the characteristic hexagon shape on the bullet, and the bullets seem to stay in place. I prefer to use dielectric silicone grease on my connectors to keep water (And therefore corrosion) at bay. Of course, using the correct sized bullet for the wire you are using really helps.

Hope this helps,

Colin.

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I've heard that soldering connections etc. can cause problems but I can only say that I rewired my Commando 22 years ago using good solder (GPO Telephones stuff !!) and have never had any problems. I use heatshrink sleeving virtually everywhere. Brittle wiring has never been an issue for me - - .

Cheers,

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Crimping gives consistent reliable connections in an industrial environment, but you need the correct gauge wire for the connector and an expensive crimp tool which is regularly calibrated to ensure sufficient compression to hold the wire securely, but not so much as to shear any of the strands.

Soldering is a skill so wildly varying results will ensue. Not enough heat or if there is corrosion or are contaminants present will result in the solder not wetting the joint properly. If you move the joint as it cools, which you will unless you clamp both sides, a dry joint will occur which has poor mechanical and electrical properties. Too much heat for too long may cause some types of insulation to shrink back or go brittle and will cause solder to wick up the wire, causing a rigid length. I would disagree with the comment about soldering heat annealing the wire and making it brittle; firstly the insulation would have gone up in smoke long before the copper got hot enough become annealed and secondly annealing softens, not hardens.

Using the cheap crimp tools which are in the price range of the home mechanic, crimping becomes a bit of a skill too, so the same applies.

I would suggest that whichever method you use, in addition to corrosion protection, the key is to ensure that all wiring is secured so one bit of it cannot move relative to another under vibration. The strands of wire which are in a crimp or are covered in solder are rigid, whereas the rest of the wire is relatively flexible. Therefore if they can move when subject to vibration , the stress will be concentrated at the interface between the two and cause work hardening and eventual cracking.

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Just a thought, I'm not much of a mechanic, but if you immobilise the wire in the bullet connector with a bit of a crimp, then fill the bullet with solder, wouldn't that give you the best of both worlds?

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Interesting comment about Lucas bullet connectors. My Dad was an auto-electrician on heavy goods vehicles (includingMighty Antar Tank Transporters) in the late 1950s/early 1960s so we had a great supply of Lucas bits in the shed! I never saw any bullet connectors on a car or bike that had been crimped. To the best of my knowledge my Dad never even had a crimping tool. He had the forked 'pliers' used to push the bullets into the connectors - I wish I knew what happened to it! The connectors would either be soldered or the wire strands protruded through the open end of the bullet and wrapped around it.

On the balance of comments posted here, I will probably solder my brass bullets on with a soldering iron, thenwaterproof vulnerable connections with silicone sealant. Don't forget that with silicone you'll have to clean and degrase the components first - drinking meths is one of the best solvents as I don't like the taste of petrol. If you don't there will be a fine, invisible debonding and it won't be waterproof. I discovered this when usingwhite silicone for internal sealing/joining uPVC windows and window boards. It looked like a nice, neat joint but hadn't actually bondedto both parts!

Cheers, Lionel

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Aerosol cans of Electrical Switch Cleaner are jolly good for degreasing components prior to soldering. Best in a well-ventilated area - my shed for instance...

Gordon.

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Lionel, I think we are talking about different bullets here. There are the ones for fitting into joining connectors, and there are different ones used to plug into voltage control units, dynamos, brake light switches etc. The second type are typically fitted by just letting the strands protrude and then wrapping them over the connector and pushing the connector home. It is the type which fit into connectors which can be crimped with the spacial tool.

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I would have thought that soldering and the heatshrink sleeve with extruding glue satisfatory, it can also be backed up with the rubber Hellermans sleeves that are available to give a bit more support to the joint. Also, it is worth checking the loom and making sure that it has been secured where needed away from vibrating parts, there is plenty of slack in the areas they cross from non vibrating ie frame to vibrating ie engine / gearbox so that the cable will not suffer undue stress. If it is secured correctly, it will vibrate together and not be problem - not secured it will move relative to what it supposed to attached to and wear through.

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Previously wrote:

Interesting comment about Lucas bullet connectors. My Dad was an auto-electrician on heavy goods vehicles (includingMighty Antar Tank Transporters) in the late 1950s/early 1960s so we had a great supply of Lucas bits in the shed! I never saw any bullet connectors on a car or bike that had been crimped. To the best of my knowledge my Dad never even had a crimping tool. He had the forked 'pliers' used to push the bullets into the connectors - I wish I knew what happened to it! The connectors would either be soldered or the wire strands protruded through the open end of the bullet and wrapped around it.

On the balance of comments posted here, I will probably solder my brass bullets on with a soldering iron, thenwaterproof vulnerable connections with silicone sealant. Don't forget that with silicone you'll have to clean and degrase the components first - drinking meths is one of the best solvents as I don't like the taste of petrol. If you don't there will be a fine, invisible debonding and it won't be waterproof. I discovered this when usingwhite silicone for internal sealing/joining uPVC windows and window boards. It looked like a nice, neat joint but hadn't actually bondedto both parts!

Cheers, Lionel

Now that tool with the forked ends is still available, but at over £20 for two bent flats of steel is really out of order. Also you will find that it is often hard to get the tool into awkward positions. This is what you do-get a small instrument screw driver (you know the one with the smooth rounded end) and use this to carefully push on the back of the bullet until it bottoms on the other bullet. Then check that first bullet hasn't been pushed out. Done. On a professional basis, (that means if I wire your bike)I much prefer to crimp, far quicker than solder, good enough for the Nortons over the years. Right size wire and connector is a good start and a ratchet crimp tool, doesn't have to cost over £20. Will give you a job as good as needed.

AL Osborn.

 


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