Where get heat shrink tape in UK?

[Alix]

I find that large diameter heat shrink sleeving which is large enough to passes over wide parts of my cables does not contract enough to hold the actaul cable when they are heated heated.

Is it possible in the UK to buy just one or two rolls of heat shrink TAPE? I mean something similar to regular self-adhesive PVC insulation tape but which contracts when heated. Does such a thing exist?

My web searches such as this one at Farnell's

return heat shrink SLEEVES which is not what I want.

[Who?]

Search for "Self Amalgamating Tape"

[Chris Whelan]

I've never seen or heard of such a product. Perhaps self-amalgamating tape will do what you want?

[Chris Whelan]

Curses! Beaten by 4 minutes!

Chris

[Matt]

50m Roll 20mm wide 0.07mm thick 130 deg C shrink temp Stock Code 170-5403 £13.15

[Dave Plowman (News)]

I doubt it as the principle is flawed.

Have you tried the type of heat shrink with the glue inside? That's what I use for the more demanding apps.

[Dave Plowman (News)]

Self amalgamating tape isn't sticky. But it's not really a substitute for heat shrink.

[Palindr☻me]

Glue-lined zipper heatshrink tubing. You open up the tubing, lay in the cables, zip the tubing shut and apply heat. Aftrwards, cut off the zipper along its length with a craft knife, to leave a round cable. Handy for all those time when you can't get a tube over the end (especially in the middle of a cable run, replacing a section of damaged cable..).

The result is a totally water and air-tight cable assembly - as the glue exudes out of the ends of the tube to make a perfect seal.

But rather over-kill for inside a PC. Spiral wrap is cheaper and more flexible - as it allows all the cables to be wrapped together, with cables exiting from the spiral wrap at intermediate points. It comes in a range or diameters.

[Dorothy Bradbury]

It sounds like you are trying to sheath cables? o Use expanding nylon braid for around the cables

---- expands as large as you want o Use adhesive lined heatshrink for the ends only

---- glue melts into the braiding to stop it coming apart

---- plain heatshrink can slide off the braiding

That will retain flexibility except around the adhesive lined heatshrink ends which will be a bit rigid. That can be minimised by using very short pieces of heatshrink, since it is the glue that seals the nylon braiding together.

Spiral wrap comes in several sizes - small o.d. to large o.d., the large o.d. is useful re cables exiting everywhere (5.25").

Self amalgamating tape is for outside applications really. It is not really suited here, it can make a right mess.

Try to aim for 3:1 low temp heatshrink vs 2:1 high temp. Quality heatshrink costs a little more, but is worth it.

Alternatively use... o More cable ties along the cable to keep wires bundled more o Velcro cable fasteners to bundle cables up as needed

Most supermarkets carry pk5-6 velcro cable ties for 79-99p. They work well re not damaging cables, easily undone/redone.

To join wires - spiral-bare-ends-into-one-another vs overlap-twist, it results in a better connection, less sharp points thro heatshrink. Note very large heatshrink will readily split on any sharp objects, and becomes rigidised (shrink increases wall thickness), so it is far better to use nylon braiding than heatshrink for sleeving.

[Alix]

"Zip the tubing shut"? This sounds clever. Do you have a link to where this product is shown?

Just what I want.

It's not inside a PC but outside. For example, I have a mic cable which plugs into the PC. It has a joint which I have made and the cable gets moved a lot. Most of the PVC insulating tape I have seen starts to open up or even unravel under the repeated flexing. So I want to seal the insulating tape on the joint or to replace it entirely with something which canbe sealed and not need any further attention.

[Matt]

No it works, as posted 3 hours ago in Message-ID:

50m Roll 20mm wide 0.07mm thick 130 deg C shrink temp Stock Code 170-5403 £13.15

[Dorothy Bradbury]

do heatshrink & adhesive lined, including 4:1 shrink.

Shortest length is 1.2m, if you just need a small piece indicate a) what size o.d. you need to fit over things and b) end size o.d.

Where o.d. is overall diameter. I may have the right size free.

Noted adhesive lined will not be flexible once shrunk, it will be rigid and can force cables to break. If the cable is not moved much this is not really important - if it is, layer non heatshrink.

[Alix]

Is there some way to stop this braid siding off the joint. It sounds as if it is in the right ball-park but I don't want it to slide of a frequently flexed joint such as one I made on my mic cable.

SOmeone esle mentioned this too. Where on the net can I see see and get it from?

My need is for a single cable and not to tidily group several cables together.

Uh oh. This is clever stuff. I havd never though of a ratio of normal to shrunk dimensions.

Once the heat-shrink has shrunk does it exert a force/tension or does it shirnk to a new reduced dimension but without any significant grip? IYSWIM.

I used to love the velcro ties. Now I prefer those green plastic plant ties with the long oblong hole which can be undone with a single tug.

Interesting to see you make a distinction. However I can not quite see the difference between the two methods you decribe. Is "spiral- bare-ends" where I bare the end of the wire, twist it so the strands are spiralled together and then, um, how do I do "into one another"?

Presumably "overlap-twist" is where the bared end of the wire are each not spiralled together to start with. And then I take the two bared ends and twist them together. Is that correct? Is this with the insulated portion of the cables side by side or with each insulated port of cable on opposing sides before the twisting together?

[Palindr☻me]

Just search for "zipper heat shrink tubing". I buy mine from my local electrical supplies company. It is used a lot to make permanent repairs to mid-sections of power cables.

Zipper tubing is *very* inflexible once set. Fine for inline repairs to cables that will not normally move but not for anything that you want to flex.

As others have said, self-amalgamating tape sounds like the answer. It will *not* unravel - as the stuff bonds to itself to make a solid covering. It will not open up.

If you cover the joint in hot-melt glue and, before the glue has hardened, wrap the joint with self-amalgamating tape, the result is almost as good as zipper tube. It can't be used for mains as the insulation thickness is uncertain (unlike zipper tube, which can be used for mains voltages and above). Be careful not to burn your fingers...

[Dorothy Bradbury]

First check Sue's zip-heatshrink, electrical wholesalers & such carry it - Newey & Eyre, City Electrical Factors (CEF) etc. Look in yellow pages, they are scattered in every town/city.

Nylon overbraid is more for internal PC cables... o The ends are uncut and will unwind/unbraid readily o So the ends are covered in a short piece of adhesive heatshrink

Many places sell it - however if you just want a small piece & I have the right size available, email, no charge. I need to know the size it must fit over (eg, a plug) and the end shrunk size.

It will grip quite strongly - but doesn't crush the cable.

o Cut the insulation off each end of wire - leaving bare strands o Push the bare strands of wire-A into those of wire-B o So each strand slides along the other wires strand o Slight twist retains it long enough for it to be soldered o Then slide heatshrink over it

Usual method is people twist wires in parallel together, solder, then flatten it down to squeeze heatshrink over - not as good.

The zip-able adhesive lined heatshrink accommodates many diameters - electrical places sell it for outside-sealing cables.

[Dave Plowman (News)]

Eh? It makes no mess at all, as there's no sticky involved. It's rather like thin PVC insulating tape without the glue. Perhaps the most common use is car wiring harnesses.

[Dave Plowman (News)]

Best thing is not to have a joint in a flexible cable. A suitable connector would be a better solution. The snag with heatshrink for this use is it's not flexible - so the cable flexes immediately before or after it and breaks. A proper connector will have a rubber gland which sort of spreads the length of the cable flexing.

The normal mic connector is of course the XLR - but this might be a bit big and heavy for this use - especially if the PC connector is the standard mini jack. If the mic and cable is getting a lot of movement, I'd fit an XLR chassis connector into a suitable instument box and weight or fix that down and run a cable from there to the PC - and plug the mic cable into the box. An XLR mic cable is designed to be flexed without damage.

[Dorothy Bradbury]

That is not self amalgamating tape - that is adhesive-less tape :-)

3 types... o PVC tape with adhesive o PVC tape without adhesive - used for looming (eg, car wiring) o Self amalgamating PVC tape with cold-flowing adhesive

Self amalgamating tape is just that.

[Frank Erskine]

On Sat, 01 Jul 2006 13:37:48 GMT, "Dorothy Bradbury" had this to say:

The only self-amalganating tape I've ever come across is poly-isobutylene (PIB) which is rubbery. It isn't actually sticky, but does have a rubbery texture. Also, it's not very durable, so it's normal to further protect it if necessary.

[Dorothy Bradbury]

That's a fourth :-)

There is a sticky version - basically a low temp cold flow adhesive, if you leave the roll for a few years it ends up a right mess. A very gummy adhesive, stretchy thin PVC to conform to irregular shapes. Either Maplin or RS sold it - threw it out long ago.

We could cover politicians in the stuff, would work for years.

Probably a variety right up to the stuff plumbers & transco use.