Graham_Wright
Well-known member
Just a thought - If the cables are soldered not end to end but side by side (as it were) with heat shrink over the double end, the stress problem might be avoided.
Joining thin wires
- Thread starter Ru88ell
- Start date
elton
Well-known member
How about some evidence for that? I'll be sure to point it out to him. I hope you'll understand I don't ask him to prove everything he says, otherwise he'd never finish a lecture.
I'm sure he's aware of the restrictions on leaded solder, but we weren't talking about commercial work.
ghostlymoron
Well-known member
It seems to me that there is more than one way to skin a cat. I know that choc blocks are said to be bad but I know of many cases where they have been used 'as a temporary fix' and are still working fine 20 years later.
Bru
Well-known member
Current British / European Standards etc.
Soldering joints has been deprecated for more years than I care to remember and is now very much a last resort as far as wiring and cabling is concerned (pretty much confined nowadays to PCB assembly and legacy products)
I suppose you'll be telling me next it''s a good idea to tin stranded cable before making a connection!
Fair enough but that wasn't clear
I'm not getting into an argument over this, it IS what I do for a living and has been for over forty years man and boy. What college lecturers teach in colleges has always been years, often decades, behind the real world and a lot of people in the industry don't know any better for that matter
Soldering two wires together, with or without heatshrink etc, has never i fact been good practice at any time although it's one we've all resorted to. However, it is now actively considered bad practice and to be avoided. Given the availability of far better alternatives, do it at your peril is all I'm saying!
Graham_Wright
Well-known member
Why? You need to explain rather than statements.
Mudisox
Well-known member
My oh my, what a lot of twisted knickers.
Can someone point me to this magic connectors, and what am I supposed to do with the 3 rolls of leaded solder?
Can someone point me to this magic connectors, and what am I supposed to do with the 3 rolls of leaded solder?
elton
Well-known member
Which standard?
Bru
Well-known member
I thought it had been adequately explained by others already
Soldering creates a hard inflexible joint which has very poor mechanical properties (albeit, done properly, excellent electrical properties). This is exacerbated when stranded cable is soldered as the solder inevitably wicks up the strands. Even within a heatshrink sleeve and taped up etc., over time there is a very real potential for a fracture failure of the cable even with very small movements or vibration
There is a further problem with the bad practice (and again, it has always been bad practice) of tinning cables before making up screw terminal connections. Over time the pressure of the screw (or similar) causes the solder to creep out from under it leading to a loose joint
Elton seems to be determined to have an argument about it but as I said through more than forty years in the electrical and electronic industry, solder joints have gone from being ubiquitous to being largely confined to PCB work as better and more reliable methods of jointing cable have become available
RCD, BSS, BMEEA Code of Practice referencing ISO10133, ISO13297, etc. etc. I don't make this shit up you know. Costs a lot of hard earned to keep up to date with it all
elton
Well-known member
A single simple reference from an authoritative source would suffice. No one's going to trawl through all that, are they?
Bru
Well-known member
Why not? I have to
Take the advice or leave it, I don't care. Like I said I'm not getting into an argument over it
elton
Well-known member
Well, this issue crops up time and time again, and no one has yet provided a reference source on the matter. You could put an end to the disagreements once and for all, simply by pointing to a specific reference..
Bru
Well-known member
I've done so. It will cost you close to a grand however to access the documents in question so how does that help?
Odd that you seem happy to take the word of a college lecturer on the one hand but won't accept the word of a qualified engineer with over forty years experience on the other
elton
Well-known member
A Google search for "iso 10133 standard", which you refer to, returns results including "The Boat Safety Scheme Essential Guide" http://www.boatsafetyscheme.org/media/164496/bss guide chap3.pdf which says:
So what are we to make of that?
David2452
Active member
I SO 13297 (2014) for a start, that is marine specific, RCD for another but that is a bit of a circular reference. NMEA0400 standard for another.
Bru
Well-known member
That a little knowledge is no substitute for a lot of knowledge
The reference you cherry picked is in regard to battery cable terminations, not jointing two wires. And that guide is more than a few years out of date (dating as it does to 2005 and referencing standards that have been updated since it was written). Plus the BSS is a somewhat parochial and in places more than a little perverse standard for inland craft which was written (arguably badly) to facilitate inspection and certification by lightly trained BSS inspectors rather than qualified marine surveyors (I should know given that I was involved in its original formulation acting on behalf of inland waterways users - it's a bit messy but nowhere near as bad as was originally proposed)
wongaero
New member
pah! Serves me right for trying to edit my post on my phone, deleted by mistake...
I use these all-in-one solder joint sleeves - you use a heat gun and get a sealed joint and can visually check its quality because the sleeve is transparent. Used on Avionics apparently
http://uk.farnell.com/te-connectivi...ve-1-7mm-clear/dp/2101891?CMP=i-bf9f-00001000
Ghastly video here
https://www.youtube.com/watch?v=24FjjIVpk9U
and here, note the pretty crowded Garmin connector - that'd be a challenge to get into its backshell unless you're super-neat
https://www.youtube.com/watch?v=uhRCUAYoSXg
I use these all-in-one solder joint sleeves - you use a heat gun and get a sealed joint and can visually check its quality because the sleeve is transparent. Used on Avionics apparently
http://uk.farnell.com/te-connectivi...ve-1-7mm-clear/dp/2101891?CMP=i-bf9f-00001000
Ghastly video here
https://www.youtube.com/watch?v=24FjjIVpk9U
and here, note the pretty crowded Garmin connector - that'd be a challenge to get into its backshell unless you're super-neat
https://www.youtube.com/watch?v=uhRCUAYoSXg
elton
Well-known member
I cherry picked nothing. I researched it and quoted a reference which supported my argument, which is more than you've done.
So, another who can't quote a reference
What I find is https://xanthiona.files.wordpress.com/2010/03/iso-13297-ac-current.pdf which says
In my interpretation of the above, it does not preclude soldered connections; it is simply specifying that if a crimping tool is used to make a connection, then it should meet the requirements stated.
Furthermore ISO 13297 covers only AC installations (eg 230V mains) , and not low voltage DC wiring.
ghostlymoron
Well-known member
I think you're all going a bit overboard on this and taking it too seriously.
maxcampbell
New member
After reading this, I, for one, accept that tinning and soldering are not a good idea - and I've done both in the past.
Why are choc blocks worse than crimped connections, or those push-fit choc-block-like things?
Why are choc blocks worse than crimped connections, or those push-fit choc-block-like things?
Bru
Well-known member
Wires creep over time when directly inserted into screw terminals for one thing. Even when not tinned although that makes the problem worse.
Elton will doubtless howl with fury but current best practice in industry, both marine and general, is to always use crimp bootlace ferrules on cables that terminate in a screw terminal
Also, standard "choc bloc" is pretty poorly made. If at all possible, I prefer to use decent quality terminal blocks e.g. https://www.bluesea.com/products/category/19/10/Terminal_Blocks/TerminalBlock with crimp terminals on the wires although on data connections using signal cable it's a bit OTT and that's where the aforementioned Wago connectors &c. come in.
