Flexible shrink tube - after shrunk ?

All the shrink tube I buy appears to shrivel up into a hard joint. Not normally a problem, except I am getting into these micro wires and prefer to avoid a dense hard splice. I was wondering if there was other options if anyone knew?

The larger the shrink ratio the stiffer the final result.
I have found 2:1 is softer than 4:1.
However, what you are experiencing is true.

You can strip some insulation of slightly larger wire and slide this insulation over your connection.
Silicone insulated wire is good for this.

Tell us more what is going on here.

Also, Google wire sleeving.

https://www.google.com/search?q=wire+sleeving&rlz=1C9BKJA_enCA803CA803&hl=en-US&prmd=sivn&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiQ1fqq-MLfAhVB0FQKHdRmBKUQ_AUoAnoECBoQAg&biw=1024&bih=659

larryd:
Tell us more what is going on here.

Tiny wires and leads that go to micro camera, motors, for helicopter and small car 28 gauge. I take the brains out of the toy, and wire in my own circuits. The existing device wires get too short, so I extend them. Sometimes they pinch in the plastic around the housing. It's when I have to splice around a corner somewhere is tricky.

I now realize I can just heat-gun the joint where becomes malleable again so I can sort of set them in place. I was kind of hoping that something like a rubber, latex, or silicone shrink tube was invented that someone saw, which I overlooked. Under a real pinch, I can paint on some of this "liquid electrical tape" but that is what I use for a last ditch effort or when I am too lazy to un-solder the whole harness again because I failed to pre-put the shrink tube on the wires before soldering the splice.

DocStein99:
All the shrink tube I buy appears to shrivel up into a hard joint. Not normally a problem, except I am getting into these micro wires and prefer to avoid a dense hard splice. I was wondering if there was other options if anyone knew?

You probably want rubber sleeves and the special 3-pronged expander-tool to fit them, like this: Tool for Neoprene Cable Sleeves 1.2-2.0mm Dia.

MarkT:
You probably want rubber sleeves and the special 3-pronged expander-tool to fit them, like this:

Ahh yea.... That is probably not available for 28 gauge wires. lol.

But I MIGHT be able to get away with the silicone wire strip-trick. If I strip a larger gauge wire and take the insulation from that, over the small wire - it would do the trick.

I had another idea. If I found a small straw, I could actually paint on silicone and use the straw as sort of an outside cast.

I think I am going to look into these big chemical companies, like dupont or 3m. They all have specialty gizmo's. Someone has to have thought of a shrink-tube that doesn't harden - by now, I can't invent anything.

This says “most flexible heatshrink”

For small wiring jobs like this, I some times rewire using 28 AWG wire wrap wire.

larryd:
For small wiring jobs like this, I some times rewire using 28 AWG wire wrap wire.

Good idea. I should start using that stuff more often. Its a better grade of wire altogether.

Polyolefin shrink tube is a bit more flexible than the vinyl shrink tube, though that may be a factor of it usually being thinner than the vinyl. It's still not flexible like silicone though.

The specific polyolefin tube in the link provided by Qdeathstar may be specially formulated to be even more flexible than standard polyolefin.

Why not unsolder the original wire, and replace with wire of the correct length, so you don't need a splice in the middle?

For small wiring jobs like this, I some times rewire using 28 AWG wire wrap wire.

Just be careful not to flex the wire(s) more than a couple of times. The stuff fatigues really fast!

When flex is needed, 28AWG silicone wire is great, 1.3mm OD.
https://www.ebay.ca/itm/28AWG-Flexible-Silicone-Wire-RC-Cable-Soft-Resistant-High-Temperature/132149342160?hash=item1ec4b6efd0:m:m4kiyygKh9aihM0AB2k_VLg