Polyolefin "marine" heat shrink

[jaapweel]

The other day, I was at Harbor Freight (a discount tool store, for those not in the US), and I picked up a box of assorted bits of heat shrink. What I didn't notice when I grabbed it off the shelf is that it was labeled as "marine" heat shrink. And believe it or not, this stuff is actually better than regular heat shrink.

For one thing, it's polyolefin rather than PVC. As anybody knows who has tried to shrink PVC heat shrink with a lighter, the temperature where it starts to shrink is awfully close to the temperature where it starts to decompose into smelly and no doubt unhealthy gases. With the polyolefin, I was not able to get it to that point with a lighter. That makes it much easier to work with if you don't have a hot air station on hand.

Also, it shrinks more, which is useful for things where you have a cable that already has connectors on both sides and you need to get the heat shrink all the way down to the diameter of the cable. For instance, in the attached picture, I used a piece of heat shrink to permanently attach an old-Magsafe-to-new-Magsafe adapter to an Apple old-Magsafe cable, also reinforcing the cable at the point where the shoddy Apple strain relief always fails. The smallest heat tubing in the box that just fit around the adapter actually shrank down almost as far as the cable. There's a small gap, but that filled up with the hot-melt adhesive that lines the inside of the tubing.