How to remove insulation from multi-strand instrument wiring

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yimkin

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I wish to connect GPS signal wires to a VHF. Despite practice my soldering ability remains poor. I want to be able to disconnect from time to time without shortening the wires each time so this rules out gel connectors. What I would prefer to do is to strip off the insulation and crimp on bootlace ferrule connectors and then make a connection using the smallest WAGO connectors. Is there a reasonably foolproof way of removing the insulation on the wires without damaging the strands?
 
Use a wirestripper suitable for the cables.
I think this is the best type, but these typically have tooling for only a few sizes of wire without changing the jaws.
https://www.ebay.co.uk/itm/Potrable...997175&hash=item1c94717902:g:dMMAAOSwsfpZ3gpK

But a good quality one of any sort with a pair of notches for the exact size of wire you are stripping should be OK.
Adjustable ones, set to the right size, are third best, they are normally cutting a round bundle of strands with a square hole...

Failing that, I roll a scalpel blade around the insulation. If you stretch the insulation slightly it may help.
 
lw395 said:
Use a wirestripper suitable for the cables.
I think this is the best type, but these typically have tooling for only a few sizes of wire without changing the jaws.
https://www.ebay.co.uk/itm/Potrable...997175&hash=item1c94717902:g:dMMAAOSwsfpZ3gpK

But a good quality one of any sort with a pair of notches for the exact size of wire you are stripping should be OK.
Adjustable ones, set to the right size, are third best, they are normally cutting a round bundle of strands with a square hole...

Failing that, I roll a scalpel blade around the insulation. If you stretch the insulation slightly it may help.
Click to expand...

Exactly the type of tool I would suggest for you (pipped at the post again!)
But I would look to pay significantly more than 3 and a half quid.

Also: At the end of the squeeze the cutters open and the jaws return to the closed position (fast), under no circumstance permit any part of your self to be in the gap... It smarts somewhat.
 
I also use a stripper but for fine wires with low intrinsic strength the radio technicians in our company would simply use a hot soldering iron to melt the insulation off. It does a neat job but mucks up the iron which then needs to be cleaned before soldering to avoid contamination.
 
If you don't have a proper stripper there is another way that will not damage the strands. Dip the end of the wire into molten solder and the insulation will retract, exposing the strands without damaging them. The method actually works but it might not be acceptable to quality control professionals.

p.s. If using a scalpel, make an incision along the length of the wire; this will not damage the strands. You can then pull the strands sideways out of the cut and be able to cut off the insulation safely.
 
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All the above methods work - it's pretty much your choice. Whichever you select, practice on some spare wire of similar dimensions unless you have some spare in the wire you actually need to strip. Even purpose made wire strippers can be a bit difficult to get set up correctly and you don't want to be practising on the few inches of wire sticking out of your radio or chart plotter.
 
Many thanks for all your comments, much appreciated. I'll try the heat related and the scalpel method on some gash wire. I have 3 sets of wire strippers but find they either don't handle the small gauge or I seem to break off some of the strands.
Using a soldering iron could be the way to go for me as I it currently resides in the 'unused' section of my toolbox.
As an aside, I do have a very heavy duty electric soldering iron which I use to heat and free up hard to reach seized bolts.
 
I've found this introduction to bootlace ferrules to be a bang on solution for joining fine signal wires ( as to a masthead wind instrument ) so that a strip connector can be used and re-used ( to save shortening the cable) but I have a query where the cable is also screened.So questions are :
Is the protection of the cable by the screening totally lost if there is a 50mm gap in a 10M cable ?
Can the screening be retained by simply connecting across the gap with a small wire ?
Is there an elegant way of retaining the screening ?
In this situation proper connecting plugs cannot be fitted and existing cables have to be re-used.
Thanks in advance to the experts.
 
bluerm166 said:
I've found this introduction to bootlace ferrules to be a bang on solution for joining fine signal wires ( as to a masthead wind instrument ) so that a strip connector can be used and re-used ( to save shortening the cable) but I have a query where the cable is also screened.So questions are :
Is the protection of the cable by the screening totally lost if there is a 50mm gap in a 10M cable ?
Can the screening be retained by simply connecting across the gap with a small wire ?
Is there an elegant way of retaining the screening ?
In this situation proper connecting plugs cannot be fitted and existing cables have to be re-used.
Thanks in advance to the experts.
Click to expand...

If the screen is braided, take the core out through the side of the screen as you would to splice a braided rope.
You can then crimp a ferrule on to the braid.
Or you can extend both braid and core with a short length of normal flex cable. This is better as you can seal the whole thing with self amalgamating tape.
Braid isoften prone to corrosion and should be kept dry, preferably sealed.
Going from screen to a short length of untwisted pair and back to screened will diminish the screening, but it is unlikely to be critical in normal boat wiring. You could twist the pair to improve it a little. Just avoid having anything really noisy or sensitive right next to such a joint.
 
lw395 said:
If the screen is braided, take the core out through the side of the screen as you would to splice a braided rope.
You can then crimp a ferrule on to the braid.
Or you can extend both braid and core with a short length of normal flex cable. This is better as you can seal the whole thing with self amalgamating tape.
Braid isoften prone to corrosion and should be kept dry, preferably sealed.
Going from screen to a short length of untwisted pair and back to screened will diminish the screening, but it is unlikely to be critical in normal boat wiring. You could twist the pair to improve it a little. Just avoid having anything really noisy or sensitive right next to such a joint.
Click to expand...

In true forum fashion I will disagree with lw395. Screened cables are mostly used to carry high frequency signals. Such signals suffer very badly where the characteristics of the conductor change. A spliced join being one such change.
There are 2 problems facing the signal, the first being that the non compliant joint may well look like a piece of soggy string as opposed to a conductor. The second, and often more devastating, is the reflection caused by such a join. This will send a reflection of the signal back up the wire to the originating circuit where it will bounce back as a ghost which will cause a blur.

You might well get away with it permanently, or you may introduce problems for the future, you wont be able to tell.
A proper connector, properly fitted will certainly not cause problems and will also protect the cable from ingress of corrosion.
 
Dougal Tolan said:
In true forum fashion I will disagree with lw395. Screened cables are mostly used to carry high frequency signals. Such signals suffer very badly where the characteristics of the conductor change.
Click to expand...

Interesting point. I'd read the OP's post as referring to NMEA 4.8Kb wires so he could get GPS info to a DSC radio. I guess if he's talking about connecting a GPS antenna to a VHF with an in-built GPS then the screening will be a lot more important.
 
Dougal Tolan said:
In true forum fashion I will disagree with lw395. Screened cables are mostly used to carry high frequency signals. Such signals suffer very badly where the characteristics of the conductor change. A spliced join being one such change.
There are 2 problems facing the signal, the first being that the non compliant joint may well look like a piece of soggy string as opposed to a conductor. The second, and often more devastating, is the reflection caused by such a join. This will send a reflection of the signal back up the wire to the originating circuit where it will bounce back as a ghost which will cause a blur.

You might well get away with it permanently, or you may introduce problems for the future, you wont be able to tell.
A proper connector, properly fitted will certainly not cause problems and will also protect the cable from ingress of corrosion.
Click to expand...

'High frequency signals'?
What I described will be fine for most things you find on a boat, other than actual radio signals. I assumed the question related to screened data lines, or maybe analogue signals such as from a wind masthead unit.
Yes a connector is always going to be better, but I took the question to relate to a situation where a cable needs to be treaded through a small hole every year, presumably from dropping the mast.

If we are talking about the co-ax for the VHF I completely agree Dougal, more so if it's the radar. I should have made that clear.
 
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