What heat-gun for solder-seal connectors?

[KompetentKrew]

Hello,

My Draper 78775 flameless gas torch is hot enough to shrink the plastic on heat shrink pre-insulated crimp terminals, but not enough to melt the solder of heat-shrink, solder-seal connectors, as in the photo below.

What kind of heat gun is recommended for this, please? Is there a gas version?

Thanks in advance for all suggestions.

 

[skipmac]

My solution would be to toss these connectors and use proper heat shrink crimp connectors with a good, ratcheting crimper. Friend years ago told me that's what the US Navy used when he was a tech in the service and I think if that's good enough for the Navy it's good enough for me. After all they can afford the time and cost to use anything they want.

However, assuming you are sold on these not sure why the solder isn't melting . The Draper should be hot enough to melt the very low temp solder used in these connectors. Possibly it is too hot and is overheating the plastic sleeve before the solder has time to heat up and melt. I tried these many years ago and was able to melt the solder with nothing more than a Bic lighter.

 

[Piddy]

Hello,

My Draper 78775 flameless gas torch is hot enough to shrink the plastic on heat shrink pre-insulated crimp terminals, but not enough to melt the solder of heat-shrink, solder-seal connectors, as in the photo below.

What kind of heat gun is recommended for this, please? Is there a gas version?

Thanks in advance for all suggestions.

I have a pack of these - very disappointing as I've tried very hot and cooler settings on my hot air gun - nowhere as easy ti use as suggested....

 

[skipmac]

I have a pack of these - very disappointing as I've tried very hot and cooler settings on my hot air gun - nowhere as easy ti use as suggested....

Well then another argument for using standard crimp fittings. The benefits:

- very strong mechanical connection IF properly done with a ratcheting crimper. The melting solder type are far interior on this

- excellent electrical connection. Other types of connectors and crimps can be as good but are not better in this regard

- very water proof.

- foolproof, quick and easy again IF one uses the proper tool.

 

[thinwater]

My solution would be to toss these connectors and use proper heat shrink crimp connectors with a good, ratcheting crimper. ---

^^ This. I've tested a bunch of those and most are complete rubbish. For starters, think about how low the melting point of the solder must be, to melt and flow before the adhesive softens! Bin them and start over.

Yeah, you'll still want a heat gun. A cheap one works fine.

 

[PaulRainbow]

Heavens, an electrical thread that i can post on where we all agree (so far) woohoo ?

So yes, bin these rubbish connectors and do as said above, glue lined crimps (if you need waterproof) and a good pair of ratchet crimps.

 

[skipmac]

^^ This. I've tested a bunch of those and most are complete rubbish. For starters, think about how low the melting point of the solder must be, to melt and flow before the adhesive softens! Bin them and start over.

Yeah, you'll still want a heat gun. A cheap one works fine.

Just the last couple of years (guess I'm a very slow learner) I have realized the value of a good heat gun. Good for removing old paint and varnish and minimize the need for chemical strippers AND best of all, amazing for removing old hoses that have molded onto the fitting. I used to fight with the hoses, expanding my vocabulary in undesired ways and usually ended up cutting off the hose with then required completely replacing a hose that was in good condition. Then tried the heat gun and magic. A bit of a wiggle and the hose pops right off.

So yes. Get a heat gun. Just one job on a hose will pay for it.

 

[JumbleDuck]

For starters, think about how low the melting point of the solder must be, to melt and flow before the adhesive softens!

Why is that bad?

 

[thinwater]

Why is that bad?

Because the solder can easily melt out when the wire is overheated.

And this is somewhat likely because of two likely (I've seen them) outcomes:
1. Cold joint. The solder is heated before the wire, which is not how you solder. Common.
2. If heated enough that the wire is above the melting point, the plastice melts and solder pours out. Yup.

There are good ones. 3M makes ones that are acceptable. But even then, it is more reliable to solder the wires and then slide heat shrink over it. Or crimp it.

I'm not anti-solder. It is just this all-in-one style that sucks.

 

[JumbleDuck]

Because the solder can easily melt out when the wire is overheated.

But that's the remelt temperature, not the eutectic melt temperature.

 

[skipmac]

Why is that bad?

The solder used in this kind of connector typically has a very low melting point. After all if you can melt it with a Bic without burning the plastic bits then it's very low. The problem, if a device on this wire draws a bit more current than usual it could easily get the connector warm enough to melt the solder again leaving you with a worse problem and potentially a fire risk as that bad connection would have higher resistance and make the overheating an even bigger problem.

 

[JumbleDuck]

The solder used in this kind of connector typically has a very low melting point. After all if you can melt it with a Bic without burning the plastic bits then it's very low. The problem, if a device on this wire draws a bit more current than usual it could easily get the connector warm enough to melt the solder again leaving you with a worse problem and potentially a fire risk as that bad connection would have higher resistance and make the overheating an even bigger problem.

But ... see above ... the whole point about solder is that it melts at a low temperature and then remelts at a higher one. If it didn't, plumbing systems would fall apart as joins were made and circuit boards woul ddismantle themselves as components were added. So it's not the first melt temperature which matters, but the second melt one. It may still be too low, of course, but a low first melt temperature isn't necessarily a bad thing.

 

[skipmac]

But ... see above ... the whole point about solder is that it melts at a low temperature and then remelts at a higher one. If it didn't, plumbing systems would fall apart as joins were made and circuit boards woul ddismantle themselves as components were added. So it's not the first melt temperature which matters, but the second melt one. It may still be too low, of course, but a low first melt temperature isn't necessarily a bad thing.

Just saw your other post after mine went. Have not researched the difference in the remelt vs initial melt but have read of cases where the solder has remelted out of this type connector. This was some time ago so newer ones may have improved characteristics but I think it's all moot. There much better solutions available so why mess with it?

 

[Buck Turgidson]

Crimp them.
Anything else is inferior.

 

[KompetentKrew]

Sorry, guys, but these connectors should be adequate for the lights in the heads:

The cables will not be stressed or strained.

I also have heat shrink pre-insulated crimp terminals (which I ended up using), but they're larger and more unsightly.

 

[jamie N]

It's going to be cheaper, easier and safer (no naked flames) to crimp them.

 

[Rappey]

Or just twist the two ends together and a little pvc tape

 

[graham]

Or just twist the two ends together and a little pvc tape
[/QUOTE
At last a quality suggestion (•‿•)

 

[AntarcticPilot]

Or just twist the two ends together and a little pvc tape

When I were a lad, that was the usual way to extend mains leads!

 

[Sea-Fever]

This guy seems to have a broad experience in the offshore industry and recommends them.... I haven't tried them myself...