How to shrink heat shrink tubing?
in [Repair]
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From: Teodor Väänänen on 12 May 2010 16:40 Jeff Liebermann wrote On 2010-05-12 21:38: > On Tue, 11 May 2010 19:41:59 GMT, mzenier(a)eskimo.com (Mark Zenier) > wrote: > >> For cable assemblies, I've found that nothing beats a Sunbeam toaster. >> Turns itself off, too. You don't have to put it down into the slot, >> just hold it over the top. > > Isn't there an interlock in the toaster that checks if there's a slab > of toast inside before it will turn on? I'm not sure I want to insert > a slice of bread for every shrink tube joint. > >> The trick with lighters is to keep the shrink about 1 1/2 to 2 inches >> above the top of the flame. > > I always manage to char the shrink tube joint when I do it that way. > It's not the heat that's causing the blackening. It's that the > burning ligher fluid is too low in temperature for complete combustion > and therefore dumps plenty of soot on the shrink tube. You can > demonstrate it for yourself by burning a lighter under a plate of > glass. The distance doesn't matter. You'll always get plenty of > soot. > > If you must use a flame, use a propane torch. Instead of 2 inches, > about 1-2 ft is about right. Don't hold onto the wire as you're > likely to burn yourself. Work very quickly and be prepared to react > if the wire or workbench catches fire. > My favorite method for shrinking shrink tubing is either ye olde lighter at 1 to 2 " distance, or the part of your soldering iron the tip fits into. Keep the heat source in motion, and no longer than is necessary for good shrinkage. Also, have spare bits and pieces to practice on, it can take a bit to get the hang of a new soldering iron or station. I don't recommend the lighter trick for anything else than small jobs, prototypes or repairs. Just my $.02 worth. /Teo. -- Teodor V��n�nen | Don't meddle in the affairs of wizards, <teostupiditydor(a)algonet.se> | for you are good and crunchy with http://www.algonet.se/~teodor/ | ketchup. Remove stupidity to reply. |
From: Michael A. Terrell on 12 May 2010 19:23 Mark Zenier wrote: > > In article <slrnhugcn1.e0e.gsm(a)cable.mendelson.com>, > Geoffrey S. Mendelson <gsm(a)mendelson.com> wrote: > >I've recently started doing electronic repairs (mostly wiring) and need to > >shrink heat shrink tubing. A long time ago I bought a heat gun used for > >removing paint and used that. It was 120 volt, so I left it when I moved > >here. > > > >I've never had much luck (or is it patience?) shrinking it by holding it over > >a soldering iron tip. Using a flame, like a cigarette or stove lighter > >ends up with burnt plastic. :-) > > > >Is there such a thing as a small heat shrink tube shrinker that does not > >toast the things around it? The largest thing I need to shrink over is > >about 1/2 an inch most of them are small (20awg or less) wires. > > For cable assemblies, I've found that nothing beats a Sunbeam toaster. > Turns itself off, too. You don't have to put it down into the slot, > just hold it over the top. > > The trick with lighters is to keep the shrink about 1 1/2 to 2 inches > above the top of the flame. Have you ever tried using one of the old 'Hot air popcorn poppers' that were popular about 15 years ago? There were used ones at flea markets for years, often in the 25 to 50 cent price range. Once you removed a few screws, the plastic case came apart leaving you a small forced air heater. :) -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: larry moe 'n curly on 13 May 2010 20:34 Michael A. Terrell wrote: > "Michael A. Terrell" wrote: > > > > <http://www.harborfreight.com/1500-watt-dual-temperature-heat-gun-572-1112-96289.html> > > $19.99 regular price. On sale for $9.99 at times. > > I received their weekly e-mail right after I posted. It is on sale > for $7.99 with the coupon below: > > http://www.harborfreightusa.com/html/wkend0517/images/2.jpg > > Here is the user manual: > > http://images.harborfreight.com/manuals/96000-96999/96289.pdf The power switched popped out 3/16" when I pressed it (2 samples), and the diode in series with the heating element is a 1N5408, rated for 3 amps average. The heater draws 8A average on low. So my question is, how long will this 3A diode last?
From: Michael A. Terrell on 13 May 2010 22:37 larry moe 'n curly wrote: > > Michael A. Terrell wrote: > > "Michael A. Terrell" wrote: > > > > > > <http://www.harborfreight.com/1500-watt-dual-temperature-heat-gun-572-1112-96289.html> > > > $19.99 regular price. On sale for $9.99 at times. > > > > I received their weekly e-mail right after I posted. It is on sale > > for $7.99 with the coupon below: > > > > http://www.harborfreightusa.com/html/wkend0517/images/2.jpg > > > > Here is the user manual: > > > > http://images.harborfreight.com/manuals/96000-96999/96289.pdf > > The power switched popped out 3/16" when I pressed it (2 samples) Then why did you buy one? Mine is fine, and I just picked one off the shelf, yesterday. I already have an old B&D, and a five year old HF heat gun. The case on the B&D melted when I had to preheat some 1.5" copper pipe while assembling the cooling system on an old TTU-25B UHF TV transmitter. I also needed an acetylene torch & a 175W Weller iron to remove some damaged copper pipe from some custom 30 year old brass fittings RCA used in that transmitter. The HF has been used to remove floor tiles, on heat shrink, and to expand metal castings to remove bearings. > The diode in series with the heating element is a 1N5408, rated > for 3 amps average. The heater draws 8A average on low. > > So my question is, how long will this 3A diode last? Where is the 1N5408 diode? It isn't listed in the parts list or shown in the drawings: http://images.harborfreight.com/manuals/96000-96999/96289.pdf How long to you use a heat gun per application? Can you read a datasheet, or only skim one? That 3 A rating is for continuous duty at a high operating temperature, not intermittent. The peak current rating is 200A. The case would likely melt before the diode would fail. <http://www.datasheetcatalog.org/datasheet/GeneralSemiconductor/mXyztrxt.pdf> I've seen four 1N4004 diodes in a bridge, in series with the heater in a hair dryer to power the dc motor on the fan. Are you claiming that a tool like that can only provide less than 120 watts of heat? -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: mm on 14 May 2010 04:14
On Wed, 12 May 2010 12:38:43 -0700, Jeff Liebermann <jeffl(a)cruzio.com> wrote: >On Tue, 11 May 2010 19:41:59 GMT, mzenier(a)eskimo.com (Mark Zenier) >wrote: > >>For cable assemblies, I've found that nothing beats a Sunbeam toaster. >>Turns itself off, too. You don't have to put it down into the slot, >>just hold it over the top. > >Isn't there an interlock in the toaster that checks if there's a slab >of toast inside before it will turn on? No, with the *automatic* Sunbeam toaster you could stick a chopstick in and push the bread sensor rib and it would go down automatically. You only had to push it down at first. It would stay down for a while after that and the only way to get it to come up early was to unplug it. Although the absence of bread might have some effect on how long it stays on. Since I never figured out how the toaster worked, the one with no handle or lever at either end, and I didn't measure the timing, I was never sure. (Measuring the timing would have required eating the toast!)** >I'm not sure I want to insert >a slice of bread for every shrink tube joint. > >>The trick with lighters is to keep the shrink about 1 1/2 to 2 inches >>above the top of the flame. Actually I may use that distance when I use kitchen matches. I haven't been doing stuff for a few months and have already forgotten. >I always manage to char the shrink tube joint when I do it that way. >It's not the heat that's causing the blackening. It's that the What does it matter if it blackens anyhow? Is it just appearance and a "professional job" you're concerned about? No one sees most of my heat=shrunk areas. **We had a Sunbeam *automatic* toaster for about 40 years, and my mother used it maybe every day of those 40 years. Just put the bread in and it went down. It broke once after about 10 years, didn't stay down long enough (or too long), even after adjusting the knob at the end, I took the cover off, and it took me at age 14 about 6 hours to get it back on. It was one piece for both long sides and the top in between, and it was spring steel of some sort, and I couldn't push it tight enough with one hand to put a screw in with the other. I tried tying it with an extension cord and twisting to make it tighter. Finally I noticed a square hole next to each screw hole and realized a narrow screwdriver in the hole could be a lever to pull the two holes into alignment. Then it took 10 minutes. I'm sure that's how it was assembled in the first place. When it was apart I just couldn't figure out what decided when it would go back up. There was no bimetal strip. There was a 1-inch square of grey metal, about 3 mm. thick that had something to do with it, that I think controlled it. Was that bimetal inside? If it moved at all, it wasn't much, because I couldn't see anything move. But I did eventually find a screw on the bottom that adjusted the time, and that's all I was supposed to fix. Turns out I didn't have to take the cover off to turn the screw. :() When it broke 30 years after that, I also couldn't figure out how it worked, and couldn't fix it. I think then it wouldn't go down at all. I never could determine what normally made it go down. The whole device is a mystery. It may be in the basement, but my mother a"h has passed away. >burning ligher fluid is too low in temperature for complete combustion >and therefore dumps plenty of soot on the shrink tube. You can >demonstrate it for yourself by burning a lighter under a plate of >glass. The distance doesn't matter. You'll always get plenty of >soot. > >If you must use a flame, use a propane torch. Instead of 2 inches, >about 1-2 ft is about right. Don't hold onto the wire as you're >likely to burn yourself. Work very quickly and be prepared to react >if the wire or workbench catches fire. |