Is Heat Shrink Tubing Flammable?

Try some PVC coated wire with metal nearby- in every Fastrack switch.

The gas produced from overheated and/or burning is both toxic and corrosive, PVC Health Hazards

• hydrogen chloride, which is a corrosive, highly toxic gas that can burn skin and cause severe, permanent respiratory damage; and
• dioxin, the most dangerous known man-made carcinogen, which will persist in the environment for a long period of time. PVC is the largest contributor to the world’s dioxin burden.

Picture does no justice, the instant corrosion of the metal cover is just crazy. I've seen similar "rusted" metal components in locomotives when similar PVC wiring burns from a derailment short. Again, this darkened area looks terrible but even worse likely will begin rusting.

Don, heatshrink is rated for a certain temperature.  If you get almost anything hot enough, it'll burn.  FWIW, joints should NOT be where things heat up if they're done properly!

Yes, heatshrink tubing will burn if you get it hot enough, so will the insulation on almost every wire used in your locomotive or layout!

Who taught you to play with matches? That's not the way to shrink tubing.

@gunrunnerjohn posted:

If you get almost anything hot enough, it'll burn.

Gunrunner, I don't know if you've ever read the book Ignition it's about the development of rocket fuels and oxidizers. One of the storys relates about testing liquid hydrogen peroxode as an oxdizer, long story short, the 911 call recording has the caller telling the operator in a rather terrified voice "THE CONCRETE"S ON FIRE THE CONCRETES ON FIRE!"

Jerry

@Arthur P. Bloom posted:

Who taught you to play with matches? That's not the way to shrink tubing.

I've used matches to shrink tubing for 45 yrs.  It takes practice but it is quick and does a good job.  Granted they didn't teach that process getting my EE degree and sometimes it tarnishes the tubing.  I have four heat guns that do pvc pipe down to very small tubing. I use those when doing multiple joints.  But for doing one or two joints, a match or a cigarette lighter is my first choice.

BTW, the best tubing has a glue coating on the inside wall.  More expensive, but worth it in my opinion.

I use a Weller iron or gun to solder splices/connections.  Then I slide the heat shrink tube over the joint and use the residual (finger off the gun trigger, iron switched off)  heat to shrink the the tubing.  No big deal.  Works just fine.  FWIW.

This is a good example of why we now have multiple warnings labels on everything. Heat shrink tubing comes in packs that tells you how to use it, with warnings about excessive heat. Many times on a layout melted wires are from excessive amps with undersized wire………this is why modern transformers have quick blow breakers, to protect the electronics and against the great unwashed.

I've used a lighter/ match for years. The long tip lighters are the best. The tubing will ignite if you aren't quick enough with moving the flame. Actually just did it the other day to fix my doorbell wiring. I didn't want to drag the gun and an extension cord outside for two joints.

I switched to a heat gun last year when I started doing ERR upgrades. Too much stuff in the way to try and stick an open flame in a loco frame.

And yes, just about anything will burn under the right conditions. You can imaging what building wiring looks like after a structure fire.

Bob

I am thinking about getting one of the battery powered heat guns at Harbor Freight.  Wonder how hot they get.

Defendant: "It takes practice but it is quick..."

Defendant: "I didn't want to drag the gun and an extension cord outside for two joints..."

As a firefighter, fire marshal, fire coordinator, code enforcement officer and county fire commission member, I have never seen a house fire started accidentally by someone using the proper heat source for shrink tubing.

I have, however, and unfortunately, seen house fires started by the injudicious use of open flames.

Plumbers sweat copper pipe joints using a torch, often near wood framing or other stuff that will burn.  Sure, you can (should) use the foil-covered insulating pad between the work and the wood (which is what I do for my projects), but how often have you seen singe marks on the wood near a solder joint?  Just make sure that everything has cooled off and nothing is smoldering before leaving.

And there's always "hey y'all, watch this!". 

@aussteve posted:

BTW, the best tubing has a glue coating on the inside wall.  More expensive, but worth it in my opinion.

Actually, to be perfectly blunt, I think the shrink tubing with the glue is the worst choice unless you're planning on running your trains in the rain!  There's no benefit to it for the environment we run our trains in, or at least the environment that mine experience.

"Plumbers sweat copper pipe joints using a torch, often near wood framing or other stuff that will burn."

You left out the "Licensed and insured" part.

@baltimoretrainworks posted:

Gunrunner, I don't know if you've ever read the book Ignition it's about the development of rocket fuels and oxidizers. One of the storys relates about testing liquid hydrogen peroxode as an oxdizer, long story short, the 911 call recording has the caller telling the operator in a rather terrified voice "THE CONCRETE"S ON FIRE THE CONCRETES ON FIRE!"

When I was sixteen, I decided to see how magnesium burns.  We took a chunk of magnesium rod outside the hanger at the airport and lit it with an oxy acetylene torch.  BOY, does it burn!  However, I hadn't given much though about how to put it out, turns out that's next to impossible!  We finally buried it in a huge mound of sand and eventually it did extinguish it.  What a mess, it made a trench in the concrete and when it got to the blacktop, it really made a mess!  My father was less than impressed!

@CAPPilot posted:

I am thinking about getting one of the battery powered heat guns at Harbor Freight.  Wonder how hot they get.

Hot enough to shrink tubing I'm sure.   Heatshrink doesn't take that much heat to do the job, much of it is rated at 125C.  I find when I wave my wand over it at 200C, it shrinks very quickly, and it never catches fire.

@gunrunnerjohn posted:

Actually, to be perfectly blunt, I think the shrink tubing with the glue is the worst choice unless you're planning on running your trains in the rain!  There's no benefit to it for the environment we run our trains in, or at least the environment that mine experience.

Actually it’s not glue, though it has the same catalyst as some glue it’s a dye-electric insulator to stop moisture from moving along the wire as some have groves in the jacket.

I know it's not really glue, but that's a moot point as it turns into glue when you heat it!  My whole point is, if you have moisture traveling up your wires, you have a much bigger issue than worrying about what kind of heatshrink you're using!