Heat shrink caps.

Nov 24, 2018 Last reply: 7 years ago 19 Replies

Anyone know of a source of these - preferably in a range of sizes? The sort of thing you'd use to cap the end of a wire (not mains but say car wiring) So a tube with one end sealed.



I'm fixing up an old car loom, and this is how Lucas did it where groups of wires are permanently joined. The ends sort of branch out from the loom and are crimped and soldered and this cap over the ends to insulate them.



Something like self amalgamating tape would do a safe enough job, but it would be nice to do it like the original.


I have not seen heat shrink caps but you might be able to create something similar using the type of heat shrink that is lined internally with glue. Leave the length of heat shrink proud of the end of the wire and simply crimp the protruding end with pliers as it actually shrinks, the glue should then produce an effective seal at the end.

Richard

Lots of hits on google including CPC but the prices will put you off!

Or for a slightly neater version, slip a length of ordinary heat shrink twice as long as needed over the wire(s), shrink, fold double, then slip a length of sticky heat shrink over that, slightly protruding, and shrink. You should get a double layer of insulation over the exposed end, first from the folded heat shrink and then from extruded "glue".

I had the problem some time back, maybe not quite as neat but stick the heatshrink over the cables leaving 3-4 cm extended beyond the ends and shrink.

When still pliable fold the excess back and quickly slide on a fresh piece of heatshrink with the end flush with the "sealed" end.

Reheating the heatshrink will compress the fold neatly.

I am not sure, but I think that the same diameter heatshrink could be used for the folded initial bit and the overall cover. You may have to go up a little in size though for the final "cover".

Timing is fairly important. Too hot and the final cover will shrink as it is being slid on. Too cold and the first heatshrink tube will be hard to compress.

I did it without gloves and the end result was used in MOD projects. While not strictly adhering to any specification available to me, the units were inspected and went into service in exposed conditions.

AB

Yes - all sorts of ways. Even normal heat shrink bent over and held with pliers while you shrink it. Then another layer to hold that in place.

Just being picky, as the original does show as a nice neat cap.

Yup - that's one way I've tried. See the post I've just sent before reading yours.

or just dip the wire into something waterproof. Bitumen paint, rubber glue, resin, what have you.

NT

Are you serious?

After seeing the level of ignorance you clearly have over social topics, I am truly impressed that someonecan have so little knowledge on almost every other subject under the sun.

Are you new to this planet?

AB

3M Heat shrink cable end caps?
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Brilliant, thanks Alan. You're obviously better at searching than me. ;-)

They don't seem to keen to sell them though - 'buy now' gets you to a request a quote' page.

lots on amazon.

there are crimp on ends and screw fit ones too.

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That was just one example seller Just search for heat shrink caps

You may not like the prices. 15mm @ 60p each

you're free to say why you think it won't work.

Sometimes I've thought similar of you. Why not keep it to more factual responses on why you think dipping would not work. Hint: I used to have a bunch of gloop dipped items. It was a standard way of coating tool handles. What was it, plastidip or something like that.

NT

A company called Rachem used to make lots of shaped caps and other things that were heat shrinkable in packs. Not seen them lately though. They also used to sell horribly expensive heat shrink hot air guns and nozzles too. Brian

Given I've got the full name thanks to the link you gave, I found some on Ebay. They do seem expensive for what they are, but given how few needed, probably not a problem. The size(s) I need would have to cover about

5-10mm diameter. Being Ebay, several are selling one off at a highish price. I'll look a bit further for a better deal of say 50 and it doesn't matter if I have to wait for them to come from China.

Heatshrink should shrink to 50% of its original size so, if you can find some which is a snug fit over the end and leave it a bit overlong, that should do the trick.

If you want to me extra safe, put a short length of plastic rod (plastic knitting needle?) the same diameter in the end.

I'd like it to be as moisture proof as possible given the hostile environment that car wiring has to survive.

But I've found a Chinese supplier of the right thing at a reasonable price. About 15 quid delivered for 20 each of two sizes and two colours (80 total)

He does seen ignorant of technical things sometimes.

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