[sdiy] Large heat shrink alternative (cling wrap)

[Steve Lenham]

On 12/06/2020 16:49, John Speth via Synth-diy wrote:
> Does anybody have any experience or knowledge about food grade LDPE 
> cling wrap long term performance in heat shrink applications?

I mean this in the nicest possible way - really - but...that is a 
terrible idea!

Reason 1: anyone who opens up that instrument in the future will 
instantly consider you a bodger of the highest order.

Reason 2: to stick together, normal (food) shrink wrap relies on a 
static charge that is generated when you pull it off the roll. Once that 
charge dissipates, it's just...plastic. Without some other mechanical 
support it will end up lying in the bottom of the enclosure. You mention 
that you are warming it, but probably not enough to melt the layers 
together, so it will still start to unravel as soon as you turn your back.

Reason 3: it isn't as difficult as you think to do it the right way (see 
below)

> I'm doing an organ repair in which I need to physically gang capacitors. 
> For that I'd need 4 inch heat shrink tubing. It's around total $50 for 
> me to get 4 feet of it from Mouser, too much for me.

If you shop around, you can do so much better than that - like by a 
factor of twenty. Thin, large-bore heatshrink is very widely used for 
making battery packs, so look for suppliers who serve the remote-control 
car/plane fraternity - or simply eBay. This won't help you if you are 
outside the UK, but as an example:

https://www.componentshop.co.uk/clear-shrink-wrap-100mm-wide-price-per-metre.html

100mm heatshrink (so about 4 inch) at GBP1.60 per metre (about US$2.00 
for 3 feet). They have loads of other bore sizes too.

As someone who works on quite a lot of old gear, the things that I would 
be happiest to encounter were I to open up your organ would be, in order 
of preference:

1. Proper heatshrink.
2. Cable ties.
3. Hot glue.
4. A million other things including bulldog clips and string.
5= Blood stained rags, loosely tied.
5= Cling film.

Hope this helps ;-)

Steve L.