temperature for shrinking heat-shrink insulation

You may be over-thinking this. Get a couple of feet of shrink tube and your favorite hot air gun and try out a few representative tests. I think that you'll find that it isn't hard to gauge a good working distance that shrinks the tubing without melting or charring it.

In a pinch, an ordinary butane lighter and some moderate dexterity does the trick.

For really big jobs, there are nozzle attachments that partially wrap around the cable to distribute the hot air more evenly. With smaller stuff it's usually sufficient just to move the air around to heat all sides more-or-less the same.

It wouldn't be the first time. :-)

I'm asking mainly because I haven't bought the sleeving & gun yet, so I want to make sure I get suitable equipment.

Besides, shrink tubing is pretty robust. You almost can't overheat it. I vaguely recall a part we had to shrink wrap very tightly over two diameters, almost beyond the tubing's capability. By applying very high amounts of heat --almost an open flame-- we were successful. The tubing held up beautifully under this kind of abuse. You can, in fact, destroy shrink tubing, but it takes some effort. ;)

nb

This kit (link is Mouser but also at Digikey, Newark, etc.)

may be a good place to start, then. I have a similar kit that I use at home -- may be the same kit but they had a slightly different hot air gun at the time I got mine some years ago. The picture at Digikey is closer to the one I've got.

If you're doing something like big-ass shipboard cable then you'll want a correspondingly larger hot air gun and a deflector but for "ordinary" use, the small gun in the kit above will work just fine and is less likely to set the carpet on fire.

Also, 100 ft reels aren't terribly much more expensive than the onsie-twosie little pre-cut pieces in a kit so if you're using a lot of a particular size, get it in bulk.

Just hold the gun on it until the tubing shrinks, then stop.

Rotating the part once the tubing starts to shrink helps a lot -- otherwise you'll overheat the near side, and not shrink the far side.

Of course, using a fancy adjustable gun with a nozzle specifically made to direct air all around a tube works, too, but takes the challenge out of things. (It's what I'd buy if I needed to do the job frequently).

Sounds like an interesting side-experiment. ;-)

I'm just going to be playing around, not producing anything on any serious scale.

Thanks. Mainly I just wanted to make sure --- before buying a gun with 300 to 350°C setting --- that I wasn't getting the wrong tool for this.

You can get cheap heat shrink & a gun at places like Harbor Freight, to get started.

Just use a lighter or hold it over the toaster.

That's the kind of practical advice I can use.

;-)