Heat Shrink Tubing

[kfleeman1]

I have been looking at heat shrink tubing for insulating wire connections and Miniatronics, a company that makes electrical components for model railroading, says that 3/64 inch tubing is the standard size for most purposes. I don't see how this can be, because 3/64 of an inch is less that 2mm. I don't see how this will even slip over a wire. Am I missing something?

[Anonymous]

It would depend on what guage of wire you are using. it comes in all different sizes. I normally take a piece of the wire I am using and size it up at my supplier. There is also a liquid form avaliable that works quit well on fine work.

[dbduck]

one point to remember....most heat-shrink tubing will shrink to half it's inside diameter while the wall of the tube will double in thickness

[Texas Zepher]

QUOTE: Originally posted by kfleeman1
I have been looking at heat shrink tubing for insulating wire connections and Miniatronics, a company that makes electrical components for model railroading, says that 3/64 inch tubing is the standard size for most purposes. I don't see how this can be, because 3/64 of an inch is less that 2mm.

Consider the size of most of the wire used by Miniatronics components. 2mm is plenty big to cover a connection with them. It is perfect for the leads that come on most DCC decoders too. That is the size I use most of the time.

[MisterBeasley]

Heat shrink is really for things like wiring decoders or locomotive headlights, where space is at a premium and, even though you can't see it, neatness really counts. I've taken to using only heat-shrink inside my locos, and it makes a world of difference vs. insulating with electrical tape. Inside the locomotives, everything is #24 or #26 wire, so the small tubing works great.

Out on the main, though, where I'm using bigger gauge wire, I use electrical tape. Cheap, easy to use and readily available, it's the right technology for busses, feeders and all those building lights. If you start using heat-shrink for everything, you'll discover you go through a package pretty quick, and retail outlets like Radio Shack really gouge you for stuff like that.

[Anonymous]

I am going to beg to differ with MisterBeazley - electrical tape turns into either a sticky mess after a few years or a dried out mess! Unwrap a joint covered in electrical tape and the first thing youwant to reach for is the solvent dispenser and a cloth to clean it up. Yucky messy stuff.

Of course, heat shrink makes the joint a one time thing, unless you are very deft with a scalpel or Exacto knife you aren't going to uncover the joint easilly.

Heat shrink tubing is available in a variety of materials, the most common being polyolefin. The common product has a 2:1 shrink ratio. For this material I find ebay and excellent source and I often buy the smaller sizes in pre-cut bags of around 1" length. Usually I can find bags of 500 pieces for between $5 and $7 in a selection of colors.

For more specialised heat shrink, including high ratio (4:1 shrink), glue lined or specialised materials I would tend to buy from http://digikey.com , http://mouser.com or http://www.newark.com . All of whom are reliable sources.

John

[Seamonster]

QUOTE: electrical tape turns into either a sticky mess after a few years or a dried out mess! Unwrap a joint covered in electrical tape and the first thing youwant to reach for is the solvent dispenser and a cloth to clean it up. Yucky messy stuff.

[#ditto][#ditto][#ditto]

QUOTE: Of course, heat shrink makes the joint a one time thing, unless you are very deft with a scalpel or Exacto knife you aren't going to uncover the joint easilly.

It can be done--very carefully--with the point of a #11 Xacto blade but it's easy to cut yourself doing that.

QUOTE: If you start using heat-shrink for everything, you'll discover you go through a package pretty quick, and retail outlets like Radio Shack really gouge you for stuff like that.

Buy it in 3' lengths from an electronics distributor or mail order. Much, much cheaper.

[rlandry6]

I use it for my decoder installations. decoders come with #30 wire, very small. The smallext size heat shrink will cover the conections nicly. Although not recommended for solder connections that need a good mechanical conection, it's ok to position the wires side by side and hold them there with forceps while you.solder them. It make an almost unnoticeable connection and the heat shrink goes on it really smooth. Don't forget to put the tubing over the wire first. You need a heat source to heat the tubing. You run a risk of damaging something by using one of the commercial heat guns. There are several companies that make a great little portable heat gun that runs on a disposable butane lighter. it provides 1200 degrees of directed heat with no open flame. Street price is about $30. great little tool..

[warhammerdriver]

As an automotive electrical tech, i have to say that heat shrink is definitely the way to go. If you use the glue-less kind, a seam ripper will slice it open very well. (Got my seam ripper from Wal-Mart for less than 2 bucks).

[Texas Zepher]

QUOTE: Originally posted by rlandry6 Although not recommended for solder connections that need a good mechanical conection, it's ok to position the wires side by side and hold them there with forceps while you.solder them. It make an almost unnoticeable connection and the heat shrink goes on it really smooth.

Under a magnifying glass, I always cross them, hold them with the forceps and twist the loose end of one around the other than switch and do the other side. That makes a great mechanical connection, then solder. That way I don't need to hold them while soldering, they hold themselves.