Heat Shrink tubing

ronk · Post by **ronk** » Tue Aug 10, 2021 9:27 pm

I’ve got four joints on 25mm dia tube to seal.
I am going to buy a length of 50mm heat shrink (100mm circumference)

The material will certainly shrink down to the required 25mm diameter but how much will it shrink in length if any?

Chippie · Post by **Chippie** » Tue Aug 10, 2021 9:44 pm

50mm seems a little large for the 25mm Tube, can’t you get say 30mm, from past experience (although not a lot) I don’t think it shrinks much if anything in its length, but a larger diameter may tend to twist and crease

PerryGunn · Post by **PerryGunn** » Tue Aug 10, 2021 10:12 pm

ronk, do you mean the heat shrink tubing is 50mm long and about 31mm diameter (which gives 100mm circumference)?

If so, it'll fit fine - you'll get from 5% to 12% shrinkage along the length (depends on the plastic used to make it)

ronk · Post by **ronk** » Tue Aug 10, 2021 10:20 pm

My choice of 50mm (flat width) was based on it being a nominal 100mm circumference and the 25mm dia Tube 75mm nominal circumference .

Is the 50mm (thus 30mm dia) the flat measured width? That was my assumption.
Pictures on eBay seem to show the material in a flat condition?

PerryGunn · Post by **PerryGunn** » Wed Aug 11, 2021 8:40 am

ronk wrote: ↑Tue Aug 10, 2021 10:20 pm My choice of 50mm (flat width) was based on it being a nominal 100mm circumference and the 25mm dia Tube 75mm nominal circumference .

Is the 50mm (thus 30mm dia) the flat measured width? That was my assumption.
Pictures on eBay seem to show the material in a flat condition?

Yes, heatshrink seems to come flat - it's possible that some doesn't but I've never run into any.

It's probably worth checking that the eBay seller is quoting the ‘lay flat width’ rather than the ‘expanded inside diameter’ of the tubing - either can be used but the ‘expanded inside diameter’ is more standard and should be printed on the heatshrink.

Z4-forum.com

Z4-forum.com