Proper way to make a slim waterproof wire splice.

[Beowulf]

Proper way to make a slim waterproof wire splice.

Here is my idea for making a nice water resistant wire splice. This would be for my fog lights.

First cut and strip both wires with about 3/8 inch copper exposed
Slide a 1.5” piece of hear shrink over one wire.
Intermingle the copper stands like pushing to hair brushes together.
Roll the intertwined strands tightly together.
Solder the connection for PVC to PVC across all exposed copper.
Slather with dielectric grease.
Pull heat shrink over solder and shrink in place.
This should squeeze most of the grease out but leaving just enough to prohibit any moisture egress.


Let me know what you think. Is there are better way? Is this overkill? I only have to do four splices so it should not be too bad.

Are there special solders I should use? (don’t even know if there are different solders)

 

[Scott Brady]

Proper way to make a slim waterproof wire splice.

Here is my idea for making a nice water resistant wire splice. This would be for my fog lights.

First cut and strip both wires with about 3/8 inch copper exposed
Slide a 1.5” piece of hear shrink over one wire.
Intermingle the copper stands like pushing to hair brushes together.
Roll the intertwined strands tightly together.
Solder the connection for PVC to PVC across all exposed copper.
Slather with dielectric grease.
Pull heat shrink over solder and shrink in place.
This should squeeze most of the grease out but leaving just enough to prohibit any moisture egress.


Let me know what you think. Is there are better way? Is this overkill? I only have to do four splices so it should not be too bad.

Are there special solders I should use? (don’t even know if there are different solders)

That looks right. Some new shrink tube has waterproof grease integrated. Makes it a little easier.

 

[Robthebrit]

That is exactly what you do, but experiment with the grease. Alot of the high quality shrink tubing has an integrated glue which activates when it gets hot. The grease might stop the glue from sticking to the wires.

Does it have to be 100% water proof? Once a good solder joint is in place there is very little chance of corrosion (no more than an exposed wire because there is no friction joint). An semi exposed solder joint is much better than the typical crimp on connectors.

Rob

 

[hoser]

How about Liquid Electrical Tape.

 

[mog]

In the past I've used waterproof butt connectors from AMP. When you use a heat gun to shrink them, you can see the 'sealent' melting and sealing the wire. They are very high quality but are priced accordingly, so unless there are extras to hijack from work, I used the method you described, but without the grease. The solder and quality shrink-wrap seals just as well as a normal wire IMO.

http://www.wiringproducts.com/index1.html
Heat shrink butt connectors are adhesive-lined and color-coded to industry standard wire range. Heat shrink protects against corrosion and the adheisve makes the connector waterproof. Excellent splice for marine, automotive, outdoor, or harsh environment use. The translucent heat shrink allows for visual inspection of the connection, and has the wire gauge printed on it.

 

[BogusBlake]

What you originally posted will work, but I would use a "J-hook" between the wires instead of a butt joint. That would make if better structurally. To make this joint, strip about 1/2 to 5/8 of each wire and bend them to hook together. Roll the hooks with your fingers to compress the joint then flow the solder into the joint. Slide the shrink sleeve on then shrink it. The bulge from this type of joint is only slightly larger than a butt splice but won't pull apart if the wire gets strained.

Like the other guys said, get some shrink sleeve with heat activated adhesive. Also, use rosin core solder meant for electronics.

 

[david despain]

http://www.edmo.com/index.php?module=products&func=display&prod_id=19473&cat_id=461
or these are even better, http://www.edmo.com/index.php?module=products&func=display&prod_id=18889 of course they require a special crimping tool so thats an extra cost, but i gaurentee you a most bulletproof connection.

 

[Beowulf]

Great discussion. Do you need to use a special heat gun for those connectors?

Also what is a good quality soldering iron to use if I go old school and use normal heat shrink?

 

[pray4surf]

Great discussion. Do you need to use a special heat gun for those connectors?

Also what is a good quality soldering iron to use if I go old school and use normal heat shrink?

Great discussion - I agree..

I've done my connections just like you have described, but after reading this thread, all future connections will be of the 'j-hook' style. Mechanically a stronger fit - of course, your wiring shouldn't be exposed to any stress.

Haven't read the link that david despain provides - so I reserve the right to change my mind

Rick

 

[Beowulf]

Let's throw a wrench in the works here. What to do when you have to splice a factory supplied foglight wire, 12 gauge, to the OEM vehicle foglight harness that is around 16 gauge?

Do you first have to put on a small piece of 16 gauge heat shrink on the smaller wire and then pull the larger 12 gauge piece over that and the 16 gauge wire? Or does 12 gauge heat shrink decrease in size enough to do the job?

 

[Robthebrit]

With shrink tubing that is always a bit of a pain, sometimes you get lucky and the tube shrinks enough, it all depends on the relative sizes. You probably won't get a real good seal on the smaller wire. I would look at the high quality mechanical connectors people talked about above.

Rob

 

[UK4X4]

Good quality heat shrink will easily take up the diference, use 3M with the glue, no grease.

if a joints properly soldered, its solid....what ever you do to the wires

If you have to do a couple of splices also run another larger heatshrink over the two splices......remember to put this on first

A soldered joint is physically stronger that the wire itself, but its stiff too,

soldered joint failure is usually the wire itself, at the point where it enters the solder, so the stiffer and less movement the joint has...the longer it will last

 

[elcoyote]

Pico "Heat Shrink, Crimp and Solder" connectors are the easiest to use and are bombproof IMO

http://www.picocanada.com/catalogue.asp

 

[mog]

...A soldered joint is physically stronger that the wire itself, but its stiff too,
soldered joint failure is usually the wire itself, at the point where it enters the solder,...

This is why on aircraft (I'm a corporate aircraft mech.) we mostly use connectors instead of soldering. But we are using quality connectors traceable to a source (not Chinese ones from Harbor Freight), stripped with correct wire strippers, and crimped with calibrated crimpers. That being said, on my vehicles, I'm about 50/50 with crimping and soldering. I use crimps for a quicker job with a few wires and out of the weather. If I have a bunch of wires, especially small ones for speakers, etc, or stuff that will be exposed, I solder and shrink-wrap. And as other have said, use a quality solder along with the proper size quality srink-wrap.

 

[ntsqd]

On various automotive forums the solder vs. crimp debate has been raging for over a decade. I'm slowly moving away from soldering. Main reason being that fatigue failure mode noted above. Where the solder stops creates a stress riser. Most notable had me standing beside my totally powerless vehicle in the middle of the Mojave Desert. Fortunately I'd wired that vehicle from scratch so I knew where the failure was likely to be, but it still took a while to fangle a repair.

The Western-Union splice is how I was taught to make such splices. W-U needed a splice that was easy to make, mechanically strong, and electrically conductive. Used to be I'd solder them and then wrap with electrical tape. Now I may or may not solder them, and then cover them with adhesive lined heat shrink. In a pinch I've been known to use a ciggy lighter on the heat shrink.