Model Railroading > Proper Shrinking of Heat Shrink Tubing

This may sound like a silly question, but is there a trick to getting heat shrink tubing to shrink? I tried using a hair dryer and it didn't really work, the soldering iron wasn't much better, and finally I used a match but almost melted the insulation on the wires. So is there a trick?

I do suppose that you should use tubing that is only slightly larger than the wires.

Gee, the joys of going to DCC. <grin>

Charles

Most electronic and electrical guys use an heat gun, similar to a hair dryer, but much hotter. I have used them before and they work great, but even they get so hot they can melt insulation if you get it too close. They are also rather expensive, but you can get the type used by the RC airplane guys. They are a cheaper than the ones you would get for electrical work. The RC guys use them to shrink the covering for their airplanes.

Check these out. From $13 on up to $160.

http://www.amazon.com/gp/browse/?node=554570&amp;lposid=u7-9784203-7,C,1640

Ron Evans
Golden Valley, AZ

I use a small candle. Just hold the tubing far enough above so it doesn`t melt but still shrinks. Beats strikng a bunch of matches and cheaper than buying a gun.

twl

Charles Wrote:
-------------------------------------------------------
> This may sound like a silly question, but is there
> a trick to getting heat shrink tubing to shrink?
> I tried using a hair dryer and it didn't really
> work, the soldering iron wasn't much better, and
> finally I used a match but almost melted the
> insulation on the wires. So is there a trick?
>
> I do suppose that you should use tubing that is
> only slightly larger than the wires.
>
> Gee, the joys of going to DCC.
>
> Charles

I use a soldering iron but not the tip of the iron. The tip screws into
a metal socket which in turn is connected to the plastic handle. The metal
socket is hot, but not as hot as the tip and I move the iron back and forth
along the tubing until the tubing shrinks around the wire.

This is the method I use and it works very well. I have found though that all shrink tubing is not alike. I purchased some shiny black shrink tubing at Radio Shack that refused to shrink except with very high heat. I have since purchased some at Home Depot (dull grey)that works OK using this method.
ArgyleEagle Wrote:
-------------------------------------------------------
> I use a soldering iron but not the tip of the
> iron. The tip screws into
> a metal socket which in turn is connected to the
> plastic handle. The metal
> socket is hot, but not as hot as the tip and I
> move the iron back and forth
> along the tubing until the tubing shrinks around
> the wire.

First of all make sure you have shrinkable tubing and for best results use only a size slightly larger in diameter then you need. It will only shrink so much. There is tubing out there that is non-shrinkable. A heat gun or hair dryer will work as I have used both for years. A heat gun is nothing more then an industrialized version of a hair dryer. Soldering irons, candles, and other items will work but can screw up your work if not very careful. Using heat guns/hair dryers are the preferred method.

I have to agree with AE and CR, I've seen SD-Daddy_MAC do it with a soldering iron and quickly too.
Takes a little practice maybe.


TCS - shreat hinkage

I've had great success with one of those butane "clicker" lighters. Just move the flame in and back out a few times. The tubing shrinks but the wire insulation doesn't stay in flame contact long enough to melt.

Folks;

Not a silly question in the least. After considerable trial and error...including melting a side frame...I settled on an electronic supply store heat gun and 3M shrink tubing. (here in Calif. available at Fry's) The use of lighters, matches, etc. is IMHO a poor choice and can lead to disaster. Get the right tool for the job!

Regards

Jere Ingram

Most tubing will shrink to about half its original diameter.

The heat gun is nice, but even with my commercial work I end up using the soldering iron edge or my butane powered soldering iron, the heat output is perfect for shrinking stuff.

Just like everything else, the more you do the better you get...

Randy

I don't know about you, but I get SIGNIFICANT shrinkage with my tube when it gets in cold water.

What I like to do is hang from a helicoptor from a long rope over an active volcano. As soon as the tubing shrinks, I radio the pilot that he can head back to base. Works every time.

Bruce

The method used in industry is to get a heat gun that comes with a diffuser that goes on the end of the gun to concentrate the heat around the shrink and wire..The one I use daily is a "J" shaped one. Weller makes a terrific pistol shaped gun( #6966C with the aperture close to 3/4ths of an inch in diameter..It comes with several different diffusers. Beats having a Model Locomotive flambe in your hands!

I just wait for Global Warming to shrink it naturally. Al Gore should be as proud of me as of his son for getting nailed for 100mph in a Prius!