# Heat shrink tube size



## mopac (Feb 24, 2011)

I have a question for you guys that do decoder installs. What
size heat shrink tubing do you use.? I am guessing 1/8".

Thanks for info.


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## wvgca (Jan 21, 2013)

usually 1mm or 1.5mm, 1/8 is about 3mm


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## Cycleops (Dec 6, 2014)

Don't know the size but it's the smallest.


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## redman88 (Nov 25, 2015)

For the decoder or for the wires.


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## DonR (Oct 18, 2012)

It probably wouldn't be advisable to put a heat
shrink on a decoder. They need all the air they
can get.

Don


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## mopac (Feb 24, 2011)

For the wires guys.


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## redman88 (Nov 25, 2015)

DonR said:


> It probably wouldn't be advisable to put a heat
> 
> shrink on a decoder. They need all the air they
> 
> ...




Well some manufacturers do think so


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## gunrunnerjohn (Nov 10, 2010)

It would be a REALLY small decoder to fit into 1.5mm heatshrink!


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## redman88 (Nov 25, 2015)

gunrunnerjohn said:


> It would be a REALLY small decoder to fit into 1.5mm heatshrink!




You are correct


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## wvgca (Jan 21, 2013)

DonR said:


> It probably wouldn't be advisable to put a heat
> shrink on a decoder. They need all the air they
> can get.
> Don


From what I have seen most decoders are shrink wrapped, it helps keep the 'magic smoke' from leaking out 

A noticeable exception are the light board replacement style decoders that are screw or clip mounted, and don't move around ..

As far as heat shrink tubing size for the wires, an alternative would be tubing that has a 3-1, or 5-1 shrink ratio ..it will conform to smaller sizes easier, but costs more ..

The standard ratio is 2-1. for most.


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## mopac (Feb 24, 2011)

The heat shrink I was looking at is 2-1.


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## Cycleops (Dec 6, 2014)

The shrink wrap we see on decoders is a thinner plastic material and does not hug the item like the more rubbery wire heatshrink, this allows air to pass through.


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## fcwilt (Sep 27, 2013)

I use "liquid electrical tape" - it takes a bit of time to dry/cure (whatever it does) but it is less bulky than heat shrink.


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## gunrunnerjohn (Nov 10, 2010)

Probably OK for encoders, but Liquid Tape isn't nearly as robust as heatshrink, so for many of the applications I use it for, it wouldn't work at all. Of course, taking time to dry for each connection would drive me to distraction anyway.


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