Non rust chocolate blocks

[macd]

Heat shrink butt connectors cheaper in quantity here:
http://www.altecautomotive.co.uk/red-heatshrink-butt-splice-with-hot-melt-adhesive-1844-p.asp

 

[philip_stevens]

These look interesting but how do they work? Where does the wire go in and out?

Info here

 

[Graham_Wright]

I had the same problem. I like choc blocks combined with bootlace tangs.

The answer is;- buy Maplin blocs (large ones) which accept the tangs and replace the screws with stainless grubscrews 15 mm long, preferably with a socket head. They are cheap as chips from the fastening stores (I use Allcap in Gloucester).

The Maplin choc blocks are not cheap but are a proper job.

For smaller choc blocks, remove the screws (which are almost certainly steel) and tap the connector blocks with an M4 tap (in a cordless drill is speedy). Then use the grubscrews as before.

It is possible the originals are M3 and M3 grubscrews are available;- I don't know.

 

[doug748]

Philip Stevens:

"The Wago site states that "CAGE CLAMP® technology ensures connections will be corrosion- and vibration-resistant,"

I would think the contacts are stainless steel."





Thanks Philip. They look very useful.

 

[lw395]

Personally, I get asked to help out with sorting electrical problems fairly often on friends' boats, club RIBs etc etc.
I would say the least reliable connection is amateur crimping, done with cheap tools.
The second least would be 'anything on a RIB'.
Next worst is probably the fine wire connections to masthead instruments.

Choc-blocks are OK 'indoors' on a boat, I have used them for plenty of 'temporary fixes' which have lasted many years. They do need to be kept dry, but you don't want water getting into the strands of the wire anyway.
Whatever you use, stress failure of the wire going into the connection is the enemy, so proper use of cable ties etc is the key to reliability.

 

[Boo2]

Probably still means taht you will have direct screw down onto the conductor which is a complete no no

Sorry, but what's wrong with that ? I was taught that you should always screw down to the wire and not put solder or anything on the wires first ?

Boo2

 

[philip_stevens]

Philip Stevens:

"The Wago site states that "CAGE CLAMP® technology ensures connections will be corrosion- and vibration-resistant,"

I would think the contacts are stainless steel."

Thanks Philip. They look very useful.

I have just contacted Wago UK, asking for the type of metal in the clamp.

The reply is that they are "chrome nickel steel (CrNi)"

I copy the reply:-
Good Morning Mr Stevens,

Thank you for your enquiry and I hope the following information helps.

The CAGE CLAMP is made from chrome nickel steel (CrNi), please see the
material specification attached. I have also attached the ABS (American
Bureau of Shipping), which the 222 Series is approved too. Other
advantages of using our CAGE CLAMP connection is that they are vibration
proof and gas tight (please see the CAGE CLAMP Tech catalogue attached).


Please note that the connectors are designed to be used within an
enclosure.

If further information is required please let us know.

Best regards

Michael Lane
Product Manager - Industrial Connections
phone: +44 1788 568-008
fax: +44 1788 568-050

The enclosures I use are Wiska, IP66.

The inside of a boat could be classed as an enclosure - so long as it is dry!!

Further info from Wago UK:-
They are very good connectors and very easy to use... Just be careful as we are seeing more and more copies of these from China. We are currently testing them as we don't believe they meet certain standards.

The WAGO connectors will have our logo on the housing...

Best regards

Michael

 

[john_morris_uk]

Personally, I get asked to help out with sorting electrical problems fairly often on friends' boats, club RIBs etc etc.
I would say the least reliable connection is amateur crimping, done with cheap crimp tool.

Possibly? I should have been more explicit about using a proper crimper. Mine is a ratchet type as used by most professionals I've seen. Not the cheapest, but makes good connections. Using marine grade connectors with the glue that the heat shrink is pre-lined with an which melts and seals against the wire insulation as it shrinks to fit makes a difference as well.

 

[lw395]

Possibly? I should have been more explicit about using a proper crimper. Mine is a ratchet type as used by most professionals I've seen. Not the cheapest, but makes good connections. Using marine grade connectors with the glue that the heat shrink is pre-lined with an which melts and seals against the wire insulation as it shrinks to fit makes a difference as well.

I'd agree with that, with he proviso that the crimps are the right size for the wire, and the tool is the exact right one for the crimps.
I am able to borrow most of the crimp tools I want, it's not unknown for me to have £1000 worth of them in my car!
If I don't have the right crimp tool, I will normally solder it.
Adhesive heatshrink is good, it also gives strain relief to soldered joints, or you can use self-amalgamating tape.

 

[lw395]

Sorry, but what's wrong with that ? I was taught that you should always screw down to the wire and not put solder or anything on the wires first ?

Boo2

'Posh' screw-down connections have a metal 'leaf' between the screw and the wire, so the end of the screw does not cut the strands of the wire.
The junction boxes for house wiring normally have no leaf, but screws with rounded ends.

Soldering or tinning stranded connectors before using choc-blocks avoids stray strands, but can stop the wire conforming to the shape of the connector, resulting in a small contact area.
OTOH it can seal the insulation to the wire, keeping moisture out.
It probably increases susceptibility to fatigue failure, but you need to prevent that anyway.
You pays yer money and all that.

Some people can use all the right gear and still get a rubbish result, some people use what is to hand with thought and skill and it works.

 

[doug748]

I am grateful for all the contributions.

I have a good reason for using a chocco block and an even better reason for re-using the original one, so I hope to follow Graham's advice:

"replace the screws with stainless grubscrews 15 mm long, preferably with a socket head. They are cheap as chips from the fastening stores."

This is what I intend to do, the screws on mine are 6 BA.

 

[alahol2]

I'd agree with that, with he proviso that the crimps are the right size for the wire, and the tool is the exact right one for the crimps...

After 30 odd years with various owners the wiring on my boat is a mish-mash. Is there an easy way (e.g. diameter) of identifying wire size/crimp size required as they are invariably quoted im square millimetres?
Also can anyone recommend an inexpensive crimper for 'boat sized' cables?

 

[john_morris_uk]

After 30 odd years with various owners the wiring on my boat is a mish-mash. Is there an easy way (e.g. diameter) of identifying wire size/crimp size required as they are invariably quoted im square millimetres?
Also can anyone recommend an inexpensive crimper for 'boat sized' cables?

There are tables of wire sizes available - a quick Google will find you one?

My crimper looks very similar (bit not quite identical) to this one from Maplins. It depends what you mean by cheap?

http://www.maplin.co.uk/coax-connector-crimping-tool-4234

 

[David2452]

Sorry, but what's wrong with that ? I was taught that you should always screw down to the wire and not put solder or anything on the wires first ?

Boo2

Direct screw pressure onto stranded cable can and does cause damage to the strands, you were taught wrongly. Choc blocs with tangs that press on the cable rather than direct screw pressure are the only type I could use and sign off unless bootlace ferrules are crimped on first.

 

[john_morris_uk]

Direct screw pressure onto stranded cable can and does cause damage to the strands, you were taught wrongly. Choc blocs with tangs that press on the cable rather than direct screw pressure are the only type I could use and sign off unless bootlace ferrules are crimped on first.

And the reason that terminals in domestic wiring usually don't have tangs under the screws is that house wiring uses solid copped wire. Its not recommended to use solid copper cabling on boats because of the way it fractures with vibration and movement over time. Multistrand tinned copper is the ideal solution.

When I make connections at the masthead or put bulbs in at the mast head or in difficult to maintain places, I often smear some vaseline on the contacts. Same with plugs and sockets etc. My deck plugs are still working perfectly after years and years. I had to unplug one the other day to do some tests, and the vaseline was still there keeping the water out.

 

[David2452]

After 30 odd years with various owners the wiring on my boat is a mish-mash. Is there an easy way (e.g. diameter) of identifying wire size/crimp size required as they are invariably quoted im square millimetres?
Also can anyone recommend an inexpensive crimper for 'boat sized' cables?

That depends entirely on the type of terminal you are using, I have at least seven different crimp tools for different terminal types and it is important to use the right one. A decent DIY ratchet crimper that will do up to 6mm2 is about £30 for standard terminals.

 

[richardm47]

Here they are!
Index Marine do a "range of high quality 12 way connector strips. Each strip has nickel plated brass screws and inserts plus stainless steel cable leaf protection for better connections."

http://www.indexmarine.co.uk/connector.html

 

[grumpy_o_g]

I agree - they are available, but properly crimped connectors are better.

The ones I have used (when pushed) have had the tang inside. They are stainless - or plated brass and don't corrode.

Better option would be crimped with the special marine connectors that have heatshrink stuff on them that seals onto the insulation of the wire where it enters the crimp connector? (Do the crimp and then heat with a hot air gun etc to shrink the seal onto the wire.)

If you haven't got a proper crimping tool, you might get away with soldering and heat shrink over the top? The problem is that you get a 'hard' point where the solder stops and the wire starts and the wire can eventually fracture at this point. Hopefully the heat shrink supplies enough support, but its not the optimal solution.

I will not comment, I will not comment, I will not comment... Oh buggar it, yes I will. You get a hard point where the crimp stops and the wire starts too. If you solder properly you'll end up with the stress point properly supported by the heat shrink collar.


Just for reference this is not what i call a solder tag

It's something like this

or these

a closed tube that you insert the tinned cable into with a vent at the end of the tube and often a hole drilled in the top of the tube for the same purpose.

 

[Graham_Wright]

Here they are!
Index Marine do a "range of high quality 12 way connector strips. Each strip has nickel plated brass screws and inserts plus stainless steel cable leaf protection for better connections."

http://www.indexmarine.co.uk/connector.html

Are the screws slotted head or socket? Once a head slot is damaged, it is very difficult to remove the screw.

A socket head is superior but I have never seen them in brass.

Perhaps I ought to consider a new product line?

 

[reeac]

Last Winter I did away with my mast to boat chocolate block and substituted car-style bullet connectors. No screw driver needed now and I hope that the disconnection/reconnection during laying up/fitting out will keep the contacts scraped clean. Bullet connectors are slim enough to go through the deck fitting as the connections are all down below.