Heat shrink questions

[apelly]

A recent video by funkyant put me on to the idea of clear heatshrinking over labels on cables. This sounds like a good idea to me. I asked here a while ago for cable labelling solutions, and pretty much the consensus was making a flag from those two part/laminated labels. This is what I was already doing. The real label machines (name escapes me) are crazy expensive.

Anyway, this got me thinking about getting an assortment of clear heatshrink. In the past I haven't really given a shit and just bought whatever, but I thought I'd take this opportunity to get some community perspective, in general, not just with regard to labelling, but please comment on that too if you have an opinion.

Glue/no glue?
Shrink ratio. Why do I care? Is there any real difference?
And of course, how shit is the ebay stuff compared to digikey et al.
What do you use?

[IanB]

Glue/no glue?

For labelling applications, why would this matter?

Shrink ratio. Why do I care? Is there any real difference?

This depends on the available sizes of shrink tubing and the sizes of what you want to cover. Bigger shrink ratios are good if you have a very irregular item to wrap.

And of course, how shit is the ebay stuff compared to digikey et al.

No idea.

What do you use?

I have used tubing from Fry's and from Harbor Freight. It all works.

[max666]

Shrink ratio. Why do I care? Is there any real difference?

This depends on the available sizes of shrink tubing and the sizes of what you want to cover. Bigger shrink ratios are good if you have a very irregular item to wrap

What are the advantages of less shrink ratio? Is it stronger?

[IanB]

What are the advantages of less shrink ratio? Is it stronger?

I've no idea. All the tubing I regularly find seems to be about 2:1. I only recently discovered that 3:1 tubing is even made.

[Falcon69]

and then you have double wall and adhesive lined.

I personally like the double wall adhesive lined 3:1 shrink tube, however, being adhesive lined, I am not sure it is available in transparent (clear)

[SeanB]

Adhesive lined is available in clear precut pieces from RS. The higher shrink ratio tube is good to slip over an existing connector to shrink on the label instead of cutting off the original and then replacing it. I actually do buy ready made network cabling that has the 2 shrink sleeved on the cable already, so all you do is put the label on then shrink it and you have the label done.

[German_EE]

Adhesive lined is very good for waterproofing connections.

[SeanB]

Adhesive lined is very good for waterproofing connections.

Up to a point, it does help in marine wiring, but the best solution is to first clean the insulation in the shrink area well both with fine sandpaper and then an aggressive solvent, so that you get a good adhesive bond with the plastic. Otherwise just shrinking it down will leave a thin film where salt water will wick through to make a lovely green joint.

Yamaha sells connectors that are $$$ but they do work incredibly well to fix wiring. I went through a few. Tape does not work, unless it is a self amalgamating tape and you have cleaned the wiring as above. Then it does work very well, and you can fix chafed looms without having to splice in sections provided you get it early enough.

[TimFox]

Shrink ratio question:  there are two common materials for plain (single-layer, non-adhesive) heat shrink tubing.  PVC (vinyl) has a large ratio, polyolefin has a smaller ratio.  For many critical purposes, polyolefin is a better material if you aren't shrinking around irregular objects (such as mated coax connectors), and it is easily available in clear.

[max666]

Shrink ratio question:  there are two common materials for plain (single-layer, non-adhesive) heat shrink tubing.  PVC (vinyl) has a large ratio, polyolefin has a smaller ratio.  For many critical purposes, polyolefin is a better material if you aren't shrinking around irregular objects (such as mated coax connectors), and it is easily available in clear.

Ahh, thanks TimFox!
Although I had to look up the term polyolefin , to clarify:

A polyolefin is any of a class of polymers produced from a simple olefin (also called an alkene with the general formula CnH2n) as a monomer. For example, polyethylene is the polyolefin produced by polymerizing the olefin ethylene.

Industrial polyolefins

• Thermoplastic polyolefins: polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polybutene-1 (PB-1);
• Polyolefin elastomers (POE): polyisobutylene (PIB), ethylene propylene rubber (EPR), ethylene propylene diene monomer (M-class) rubber (EPDM rubber)

[TimFox]

That type of tubing is normally called "polyolefin" in the catalogs.  I'm not sure which specific material from your list is used.

[BradC]

Up to a point, it does help in marine wiring, but the best solution is to first clean the insulation in the shrink area well both with fine sandpaper and then an aggressive solvent, so that you get a good adhesive bond with the plastic.

Just a bit of useful info as people don't tend to know where to lay their hands on aggressive solvents easily. The priming fluid used for PVC / ABS pipe joints makes a great pre-adhesive solvent (not the glue, but _priming_ fluid). Cleans, de-greases and opens up the pores in the plastic to take the adhesive. Comes stained in several colours, but is available in un-stained if you look around and is bought in the plumbing section of most home-hardware stores. It's just a mix of acetone and MEK, but the MEK gives it that extra kick.

I used adhesives a _lot_, and glue lined heatshrink is no exception. My long term success rate went through the roof when I started using this stuff to clean with first. Works for any epoxy (araldite/jbweld), acrylic, contact cement.. hot glue.. Heck, use it to clean bolts before you loctite 'em.

On heatshrink, Jaycar does a nice glue lined 4:1 that is quite good for the price.

[apelly]

I expected to be called an idiot when I started this thread, but it appears that nobody really has a strong opinion about the stuff.

Thanks for the input guys.

[richms]

Adheisive lined also can be pinched closed to seal off the end of a wire totally, which you cant do with the non lined stuff.

I also use white adhiesive lined on the ends of LED strips to insulate them etc, and then put a screw and washer thru the heatshrink to stop it peeling off.

[Psi]

If you order 3feet/1.2m heatshrink from digikey be prepared to receive a huge 1.5m long package.

[ElektroQuark]

HERE it is how I do label cables.

[m100]

In a pinch non adhesive polyolefin can also be converted to adhesive with a few thin slices taken from a hot melt glue stick.  If you do this and have an adjustable heat source then use a two stage shink, low temperature to shrink the tubing and a higher temperature to melt the adhesive.  I've sectioned them afterwards and they appear near identical in performance to off the shelf adhesive heat shrink.

[SL4P]

Heat shrink over labels is fine, except the sleeve tends to creep over time when the cable is flexed etc.
Also, the ends of the tube never shrink as evenly as the middle, but adhesive lined should be much better.
big issue is that you can't use thermally printed labels because the heat gun will cook the print while shrinking the sleeve!

[Tim F]

Ebay spec clear heatshrink without glue works fine for labels. Keep in mind that clear heatshrink generally does not hold up to UV as well as opaque heatshrink, which may or may not be an issue for your application.