crimping lugs

[mikemc]

I'm doing some rewiring mostly involving 8AWG cable and want to crimp barrel type lugs. I could take some of the wires to the local auto electrician but some are already in the boat and would be difficult to get through the conduit if lugs were pre-fitted.

Any "tricks of the trade" for crimping these lugs without having to buy the rather expensive special crimping tool?

 

[TigaWave]

probably not wt you wanted to hear, but I would always recommend soldering after crimping gently with cutters, or cheap crimping tool that comes with connectors from B&Q of course.
This will be where corrossion sets in and then the connector falls off just when you need it in 12 months time. By soldering there is no place for salty moisture to get between the two different metals.

 

[VicS]

For a reliable join you need good quality crimps and a good quality tool.

Soldering is generally not advised as it reduces the flexibility of the wire close to the joint and may lead to hardening and failure as a result. I prefer to solder though!

You are using tinned cable aren't you.

 

[Benbow]

[ QUOTE ]
....I would always recommend soldering after crimping ....

[/ QUOTE ]

There are 2 very strongly opposed schools of thought on this. Some say NEVER solder as it creates a rigid piece of wire prone to fracture. Others say always crimp and solder. I would say never rely on solder alone to make a join, and on any join - crimped or crimped and soldered - always add a decent length of adhesive lined heat shrink sleeve for additional mechanical strength and waterproofing.

 

[Evadne]

A solder join should not rely on the soldering for mechanical strength, though soldering a poorly crimped joint is one way of improving its strength. We use a lot of crimped joints in underwater instruments and failure is most likely in those that have been incorrectly crimped or crimped with the wrong tool. Crimping and soldering a joint that is prone to being moved (or made and unmade) a lot is not something I'd recommend, and a well-crimped ferrule will not pull out. Especially if you're using the right size ferrule for the wire. I get a much better join with an expensive tool. The cheapest ratchet tool in RS ( here ) is about twice what you'd pay for something that's good enough from Maplins or your local electronics or automotive shop, but it still only costs about the same as a tin of anti fouling. I would use clear heatshrink so you can see that the join is still ok when looking for problems. Waxoyl is good stuff to spray on the finished connection if its not going to be disturbed, vaseline is just as good but even more messy.
Hope this helps

 

[cliff]

[ QUOTE ]
I'm doing some rewiring mostly involving 8AWG cable and want to crimp barrel type lugs. I could take some of the wires to the local auto electrician but some are already in the boat and would be difficult to get through the conduit if lugs were pre-fitted.

Any "tricks of the trade" for crimping these lugs without having to buy the rather expensive special crimping tool?

[/ QUOTE ]If you don't know someone that has one then you could try your local tool hire shops. Failing that you can buy terminals that you use a punch to close.

I tend to crimp all joints then apply a little solder to help prevent corrosion. The crimping tool is not really that expensive - my local B&Q were doing the ratchet type complete with 2 sets of dies (one for barrel crimps and one for "F" crimps) for just £14.99.

For 8AWG I would use "F" crimps and a piece of shrink sleeve rather than barrel crimps as I have found 8AWG stranded cable does not always fit the standard yellow insulated barrrel crimp although it does depend on the make - some will.
----------

 

[mikemc]

Thanks for these very helpful comments. I'll try "F" crimps and a piece of shrink sleeve as suggested to start with.

 

[ongolo]

I have been puzzling a lot over the problem. What I do is this.

After taking insulation off and twisting the starnds again, I stick the wire into silicon grease. Dont be tempted to use vaseline, that turns into a white power in contact with sea water. then I slide a piece of shrinksleeving on the wire, crimp and solder the terminal. During the soldering process, the strands soak up the siicone grease and it seeps in under the insulation and protects the wires from corroding. If you dont do this, the wires get black and will not take solder or make a low ohm contact when recrimping or resoldering the wire. Then the shrink sleeving is brought forward over the body of the terminal.

Just my way of doing it.
Ongolo