On 12/05/2010 21:40, Teodor Väänänen wrote:
Jeff Liebermann wrote On 2010-05-12 21:38:
On Tue, 11 May 2010 19:41:59 GMT, (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.

Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

Ron(UK)

Ron wrote in message
...
On 12/05/2010 21:40, Teodor Väänänen wrote:
Jeff Liebermann wrote On 2010-05-12 21:38:
On Tue, 11 May 2010 19:41:59 GMT, (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.

Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

Ron(UK)


If you do a lot of desoldering/salvaging with one I would recommend one that
uses a ceramic matrix for the heater, the cheap ones use mica. At the moment
of pulling an IC from the board , with nozzle necessarily close to other
side, it often bangs the nozzle. My heatgun probably done a few hundred
hours , if not a thousand , over 20 years, is a Bosch with ceramic so an
easy job to repair breaks in the element with some ex-Nicad battery strip
crimped over the broken ends.



--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm

Geeezus, all this waffle -- one huge thread to avoid buying
a heat gun! A cheap one will do, fifteen quid, that`s twenty
bucks, and you can use it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering
irons, or gas lighters, when you can get the proper tool for
so little money?

Because the OP doesn't use heat-shrink materials on a regular basis, and
even 15 quid isn't justifiable. I waited years to buy one, and got it only
because it was $10.

But I agree in principle -- too many UseNet questions are elaborated to
absurdity. The Yiddish words are "tsimmes" (stew) and "megillah" (a long,
drawn-out story).

In article , Ron wrote:
On 12/05/2010 21:40, Teodor Väänänen wrote:
Jeff Liebermann wrote On 2010-05-12 21:38:
On Tue, 11 May 2010 19:41:59 GMT, (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.

Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

The ones for heat shrink do not have enough flow for paint stripping.
I got to use a Makita gun when I was doing a floor, removing melted rubber
mat. it had a continously variable heat control, like a triac controlled
system with a heat knob on the back. Thats still too much air flow for shrink.

greg

In article ,
Ron wrote:


Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

Ron(UK)

Yeah, thanks for saying that, Ron. A room full of so-called
professionals and they're all cobbing together makeshift tools. I've got
three different heat guns at work, and they're all in the over $100
range. For a homeowner who uses shrink tubing once per year, I can see
the toaster or bic lighter approach, but for someone who makes money
with his tools, ****, buy the damn tool already.

In article ,
Ron wrote:
Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

I can see that a paint stripper gun may be a bit on the large side for
some things, although it's never worried me. RS components do one
specially for this job - smaller and less powerful than a paint stripper,
but much more expensive. Part Number 545-137

--
*Keep honking...I'm reloading.

Dave Plowman London SW
To e-mail, change noise into sound.

Smitty Two wrote:
In ,
wrote:


Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

Ron(UK)

Yeah, thanks for saying that, Ron. A room full of so-called
professionals and they're all cobbing together makeshift tools. I've got
three different heat guns at work, and they're all in the over $100
range. For a homeowner who uses shrink tubing once per year, I can see
the toaster or bic lighter approach, but for someone who makes money
with his tools, ****, buy the damn tool already.

It's funny - I much prefer a butane lighter over an electric heat-gun.
It takes very little practice to get it right, it's quicker, easier to
carry, and you don't have to go looking for places to plug in the heat
gun back behind the equipment racks.

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...7/images/2.jpg

Here is the user manual:

http://images.harborfreight.com/manu...6999/96289.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?

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...7/images/2.jpg

Here is the user manual:

http://images.harborfreight.com/manu...6999/96289.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/manu...6999/96289.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.

In article ,
Mark Allread wrote:

Smitty Two wrote:
In ,
wrote:


Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

Ron(UK)

Yeah, thanks for saying that, Ron. A room full of so-called
professionals and they're all cobbing together makeshift tools. I've got
three different heat guns at work, and they're all in the over $100
range. For a homeowner who uses shrink tubing once per year, I can see
the toaster or bic lighter approach, but for someone who makes money
with his tools, ****, buy the damn tool already.

It's funny - I much prefer a butane lighter over an electric heat-gun.
It takes very little practice to get it right, it's quicker, easier to
carry, and you don't have to go looking for places to plug in the heat
gun back behind the equipment racks.

Well, each to his own. We do production work, so I'm not sure the
lighter would be appropriate for doing 400 pcs. of shrink at one
setting. It's nice to set the gun on its built-in flat back, nozzle
pointing straight up, and use it hands-free for extended periods.
Another drawback I see to the lighter is, how do you get the flame to
point down when you're working inside a chassis?

On Wed, 12 May 2010 12:38:43 -0700, Jeff Liebermann
wrote:

On Tue, 11 May 2010 19:41:59 GMT, (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.

On 13/05/2010 16:01, Dave Plowman (News) wrote:
In ,
wrote:
Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

I can see that a paint stripper gun may be a bit on the large side for
some things, although it's never worried me. RS components do one
specially for this job - smaller and less powerful than a paint stripper,
but much more expensive. Part Number 545-137


I don't want to join in a dickwaving match here but I use a Steinel 1500
watt heatgun for all heatshrink work. I`ve owned it for maybe... 15
years, I forget, It's one of those tools that is so useful, I seem to
have always had it.

When I was more active I made many many multicore cables for pro audio
work. I use the same gun for both multi core cable over an inch in
diameter, tails and singles. I never noticed a problem with the gun
being either too powerful or physically too large.

I made a little deflector attachment from sheet aluminium for when I
didnt want too much heat going where I didnt want it.

Another use for a decent heatgun is reflowing solder joints on whole
circuit boards, it`s amazing how often a good going over with a heatgun
gets a board working again.

I guess if I wanted a very small heat gun, I would buy one of those
micro blowtorch gizmos which use a BIC Lighter. As it happens I have a
Weller gas powered soldering iron which has a heat blower nozzle
attachment which is good for reflowing work.

Ron(UK)

Michael A. Terrell wrote:

larry moe 'n curly 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...7/images/2.jpg

Here is the user manual:

http://images.harborfreight.com/manu...6999/96289.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/manu...6999/96289.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?

I bought the HF heat gun yesterday, and it has a manufacturing date of
Jan, 2010. Here's a photo of the inside, showing the 1N5408 diode
across the two poles of the switch:

http://farm4.static.flickr.com/3315/...3af89634_o.jpg

The switch popped out because the lower locking tab was squashed and
couldn't lock. I think there's a bridge of small diodes at the end of
the fan motor.

Doesn't the continuous amp rating for a diode apply for any load
lasting more than something like one 60 Hz cycle (or half-cycle?). I
normally run a heat gun a lot longer than that, maybe up to 2
minutes at a time.

larry moe 'n curly wrote:

Michael A. Terrell wrote:

larry moe 'n curly 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...7/images/2.jpg

Here is the user manual:

http://images.harborfreight.com/manu...6999/96289.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/manu...6999/96289.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?

I bought the HF heat gun yesterday, and it has a manufacturing date of
Jan, 2010. Here's a photo of the inside, showing the 1N5408 diode
across the two poles of the switch:

http://farm4.static.flickr.com/3315/...3af89634_o.jpg

The switch popped out because the lower locking tab was squashed and
couldn't lock.


I've seen that in a lot of imported equipment, not just in tools.


I think there's a bridge of small diodes at the end of the fan motor.


There were none external to the motor in mine. Just two 1/8" fastons
that plugged onto the end of the motor.


Doesn't the continuous amp rating for a diode apply for any load
lasting more than something like one 60 Hz cycle (or half-cycle?). I
normally run a heat gun a lot longer than that, maybe up to 2
minutes at a time.


Have you used it for that two minutes? That should answer your
question, and show that it takes more than two minutes to damage it.

It takes time to heat the junction in the diode. The heat is
produced only when forward biased, and is from the forward voltage drop,
times the current flow. The higher the current, the faster it heats.
Since a heat gun usually gets very intermittent duty in low heat mode,
it works.

If it can handle a couple 200 amp half cycles while charging an
electrolytic in a piece of electronic equipment, it can handle the extra
current for the heating element even though it is above the 3A
continuous rating.

It looks like the motor is run from a tap on the heating element.
There is no schematic in the manual. I only saw the one diode, across
the switch in mine. Also, how often will you use one on low heat? I
rarely do, usually only when I accidentally hit the wrong end of the
rocker switch.


BTW, if that diode fails, all it will do is make it run at full heat
in either 'ON' position.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

Smitty Two wrote:
In ,
Mark wrote:

Smitty Two wrote:
In ,
wrote:


Geeezus, all this waffle - one huge thread to avoid buying a heat gun!
A cheap one will do, fifteen quid, that`s twenty bucks, and you can use
it for other stuff like paint stripping.
Why **** about with hairdryers, dodgy modified soldering irons or gas
lighters when you can get the proper tool for so little money?

Ron(UK)

Yeah, thanks for saying that, Ron. A room full of so-called
professionals and they're all cobbing together makeshift tools. I've got
three different heat guns at work, and they're all in the over $100
range. For a homeowner who uses shrink tubing once per year, I can see
the toaster or bic lighter approach, but for someone who makes money
with his tools, ****, buy the damn tool already.

It's funny - I much prefer a butane lighter over an electric heat-gun.
It takes very little practice to get it right, it's quicker, easier to
carry, and you don't have to go looking for places to plug in the heat
gun back behind the equipment racks.

Well, each to his own. We do production work, so I'm not sure the
lighter would be appropriate for doing 400 pcs. of shrink at one
setting. It's nice to set the gun on its built-in flat back, nozzle
pointing straight up, and use it hands-free for extended periods.
Another drawback I see to the lighter is, how do you get the flame to
point down when you're working inside a chassis?

And there you have it. I work with cabling in a TV station, requiring no
more than a dozen pieces done at any given time, and you work with small
wiring inside a chassis on an assembly line, doing hundreds. Each
function has its own equipment needs.

But a butane lighter - especially the "jet" types that behave like tiny
brazing torches - will flame downward well enough, unless they're built
to draw fuel only while upright.

I removed the "Hot air" tip from a butane soldering iron once, and found
it even faster than the lighter, but it required more care in use. If
one tipped it the wrong way, the flame would flare due to it drawing
liquid instead of gas butane.

Mark Allread wrote:

And there you have it. I work with cabling in a TV station, requiring no
more than a dozen pieces done at any given time, and you work with small
wiring inside a chassis on an assembly line, doing hundreds. Each
function has its own equipment needs.

But a butane lighter - especially the "jet" types that behave like tiny
brazing torches - will flame downward well enough, unless they're built
to draw fuel only while upright.

I removed the "Hot air" tip from a butane soldering iron once, and found
it even faster than the lighter, but it required more care in use. If
one tipped it the wrong way, the flame would flare due to it drawing
liquid instead of gas butane.


I used a lot of clear heatshrink to label cables for TV stations and
CATV headends. I preferred to label it before it was inside a rack,
whenever possible.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

On Fri, 14 May 2010 10:11:37 -0700 (PDT), "larry moe 'n curly"
wrote:





Doesn't the continuous amp rating for a diode apply for any load
lasting more than something like one 60 Hz cycle (or half-cycle?). I
normally run a heat gun a lot longer than that, maybe up to 2
minutes at a time.

Well, if the diode fails in short mode, you will have only high heat.
If it fails in open mode, you'll have a switch that is off-off-low!

Michael A. Terrell wrote:

larry moe 'n curly 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...7/images/2.jpg

Here is the user manual:

http://images.harborfreight.com/manu...6999/96289.pdf

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?

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.

Doesn't the continuous amp rating for a diode apply for any load
lasting more than something like one 60 Hz cycle (or half-cycle?). I
normally run a heat gun a lot longer than that, maybe up to 2
minutes at a time.

Have you used it for that two minutes? That should answer your
question, and show that it takes more than two minutes to damage it.

It takes time to heat the junction in the diode. The heat is
produced only when forward biased, and is from the forward voltage drop,
times the current flow. The higher the current, the faster it heats.
Since a heat gun usually gets very intermittent duty in low heat mode,
it works.

If it can handle a couple 200 amp half cycles while charging an
electrolytic in a piece of electronic equipment, it can handle the extra
current for the heating element even though it is above the 3A
continuous rating.

It looks like the motor is run from a tap on the heating element.
There is no schematic in the manual. I only saw the one diode, across
the switch in mine. Also, how often will you use one on low heat? I
rarely do, usually only when I accidentally hit the wrong end of the
rocker switch.

BTW, if that diode fails, all it will do is make it run at full heat
in either 'ON' position.

I'll bet customers will either not notice that the gun always puts out
full power (diode shorts), or they won't care that it doesn't work at
low heat (diode opens). I checked a few different items, including
some cheapo PC power supplies, and couldn't find any where the diodes
were underrated so much

I bought this heat gun to desolder surface mount stuff, and it seems
that its low setting puts out temperatures closer to what hot air
soldering equipment does.

Michael A. Terrell wrote:

Mark Allread wrote:

And there you have it. I work with cabling in a TV station, requiring no
more than a dozen pieces done at any given time, and you work with small
wiring inside a chassis on an assembly line, doing hundreds. Each
function has its own equipment needs.

But a butane lighter - especially the "jet" types that behave like tiny
brazing torches - will flame downward well enough, unless they're built
to draw fuel only while upright.

I removed the "Hot air" tip from a butane soldering iron once, and found
it even faster than the lighter, but it required more care in use. If
one tipped it the wrong way, the flame would flare due to it drawing
liquid instead of gas butane.


I used a lot of clear heatshrink to label cables for TV stations and
CATV headends. I preferred to label it before it was inside a rack,
whenever possible.


Indeed - whenever possible. That's how I put in the replacement
Production switcher, after all.

When the cable is to be run through the length of the building, through
tight support brackets already crammed with cable, it is sometimes best
to run one cable at a time and then label each when finished. Heh, time
for a little walk down memory lane...

Ah, the weeks I spent pulling obsolete cable out of that installation,
trying to make room for new cable... Whoever had worked there before me
had left quite a lot of work undocumented... There are few greater sins.

My Chief Engineer cracked up when I mentioned that "there is something
fundamentally wrong with any job that requires knee pads and a
squeeze-bottle of (cable) lube."

Still, by the time I was finished, the digital stuff was in and the
analog stuff (at least that which we no longer needed) was out. I even
built a set of shelves in the basement to hold the obsolete analog
equipment we hadn't sold or scrapped yet, and I carried the stuff down
and filled those shelves.

It was an interesting two years at that station, and then they laid off
more than half the staff, myself included. Ah, such is life.

Those cables were installed well, labeled well, and documented well.
And a lot of equipment that wasn't working, was, by the time I was done.

And now I'm a college student on the Dislocated Worker plan.

I imagine I'm in good company here.

larry moe 'n curly wrote:

Michael A. Terrell wrote:

larry moe 'n curly 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...7/images/2.jpg

Here is the user manual:

http://images.harborfreight.com/manu...6999/96289.pdf

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?

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.

Doesn't the continuous amp rating for a diode apply for any load
lasting more than something like one 60 Hz cycle (or half-cycle?). I
normally run a heat gun a lot longer than that, maybe up to 2
minutes at a time.

Have you used it for that two minutes? That should answer your
question, and show that it takes more than two minutes to damage it.

It takes time to heat the junction in the diode. The heat is
produced only when forward biased, and is from the forward voltage drop,
times the current flow. The higher the current, the faster it heats.
Since a heat gun usually gets very intermittent duty in low heat mode,
it works.

If it can handle a couple 200 amp half cycles while charging an
electrolytic in a piece of electronic equipment, it can handle the extra
current for the heating element even though it is above the 3A
continuous rating.

It looks like the motor is run from a tap on the heating element.
There is no schematic in the manual. I only saw the one diode, across
the switch in mine. Also, how often will you use one on low heat? I
rarely do, usually only when I accidentally hit the wrong end of the
rocker switch.

BTW, if that diode fails, all it will do is make it run at full heat
in either 'ON' position.

I'll bet customers will either not notice that the gun always puts out
full power (diode shorts), or they won't care that it doesn't work at
low heat (diode opens). I checked a few different items, including
some cheapo PC power supplies, and couldn't find any where the diodes
were underrated so much


The usual failure mode would be shorted, unless the internal
connection fractured and separated.


I bought this heat gun to desolder surface mount stuff, and it seems
that its low setting puts out temperatures closer to what hot air
soldering equipment does.


I prefer full heat for that job. I just keep it a little further
away from the board. I see less damage to boards that way. I used to
have a 6" solder pot that I would float a scrap board on, then use a
pair of pliers on the corner to smack it against something to eject all
the molten solder. I recycled thousands of 256 kb memory ICs back in
the '80s at $2.75 each. There was a huge shortage of new ICs, so they
sold as fast as I could pull them and re-tin the leads.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

Mark Allread wrote:

Michael A. Terrell wrote:

Mark Allread wrote:

And there you have it. I work with cabling in a TV station, requiring no
more than a dozen pieces done at any given time, and you work with small
wiring inside a chassis on an assembly line, doing hundreds. Each
function has its own equipment needs.

But a butane lighter - especially the "jet" types that behave like tiny
brazing torches - will flame downward well enough, unless they're built
to draw fuel only while upright.

I removed the "Hot air" tip from a butane soldering iron once, and found
it even faster than the lighter, but it required more care in use. If
one tipped it the wrong way, the flame would flare due to it drawing
liquid instead of gas butane.


I used a lot of clear heatshrink to label cables for TV stations and
CATV headends. I preferred to label it before it was inside a rack,
whenever possible.


Indeed - whenever possible. That's how I put in the replacement
Production switcher, after all.

When the cable is to be run through the length of the building, through
tight support brackets already crammed with cable, it is sometimes best
to run one cable at a time and then label each when finished. Heh, time
for a little walk down memory lane...

Ah, the weeks I spent pulling obsolete cable out of that installation,
trying to make room for new cable... Whoever had worked there before me
had left quite a lot of work undocumented... There are few greater sins.


Try a military Radio & TV station (AFRTS) where nothing was
documented. After 20& years of equipment being moved around or replaced,
it was a nightmare. I had the master monitor fail one night, but
couldn't disconnect it, because the main transmitter was at the end of
that loop. They had a nice set of Grass Valley video DAs, but only used
one of the four outputs on each. Add to that, some video connectors
were BNC, and others were PL-259 since the station was built during the
time manufacturers used both.

I got fed up with intermittent cables, so one Saturday I ran a
temporary cable from the film chain strait to the transmitter and
started pulling out dead cables. The 12" * 18" cable tray was full when
I started. When I finished, the bundle was under 6" and several
thousand feet of dead cable were laying in the corner of the transmitter
& control room. That master monitor had seven pieces of coax between it
and the video switcher. There was over 100 abandoned cables I pulled
out. Most had one bad connector, and some had both bad. The other
engineer walked in and almost fainted, but I had everything in place in
time for or noon newscast, and finished everything else before my 20
hour shift ended.


They had the audio board fail in the TV control room at one time, so
they extended all the lines to the radio station's audio console and
used the preview output to feed the TV transmitter. When they got the
board back from the AFRTS service depot, they left the extra wire
connected. You could see radio station's the AM modulation in the video
baseband, from the ground loop that mess caused.


My Chief Engineer cracked up when I mentioned that "there is something
fundamentally wrong with any job that requires knee pads and a
squeeze-bottle of (cable) lube."


Just be glad it was run above the ceiling, under a metal roof. It
was rarely comfortable up there, It was either below zero, or in the 90+
degree range.



Still, by the time I was finished, the digital stuff was in and the
analog stuff (at least that which we no longer needed) was out. I even
built a set of shelves in the basement to hold the obsolete analog
equipment we hadn't sold or scrapped yet, and I carried the stuff down
and filled those shelves.


Digital? We were B&W, and the only ICs were RTL.
(Resistor-Transistor-Logic) ;-)


It was an interesting two years at that station, and then they laid off
more than half the staff, myself included. Ah, such is life.

Those cables were installed well, labeled well, and documented well.
And a lot of equipment that wasn't working, was, by the time I was done.


I built a mobile production van for WACX in the late '80s. I used
about 50 feet of clear heat shrink.


And now I'm a college student on the Dislocated Worker plan.

I imagine I'm in good company here.


Not me. The VA has decided that I'll never work again, and it drives
me crazy.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

Michael A. Terrell wrote:

Mark Allread wrote:

Michael A. Terrell wrote:

Mark Allread wrote:

And there you have it. I work with cabling in a TV station, requiring no
more than a dozen pieces done at any given time, and you work with small
wiring inside a chassis on an assembly line, doing hundreds. Each
function has its own equipment needs.

But a butane lighter - especially the "jet" types that behave like tiny
brazing torches - will flame downward well enough, unless they're built
to draw fuel only while upright.

I removed the "Hot air" tip from a butane soldering iron once, and found
it even faster than the lighter, but it required more care in use. If
one tipped it the wrong way, the flame would flare due to it drawing
liquid instead of gas butane.


I used a lot of clear heatshrink to label cables for TV stations and
CATV headends. I preferred to label it before it was inside a rack,
whenever possible.


Indeed - whenever possible. That's how I put in the replacement
Production switcher, after all.

When the cable is to be run through the length of the building, through
tight support brackets already crammed with cable, it is sometimes best
to run one cable at a time and then label each when finished. Heh, time
for a little walk down memory lane...

Ah, the weeks I spent pulling obsolete cable out of that installation,
trying to make room for new cable... Whoever had worked there before me
had left quite a lot of work undocumented... There are few greater sins.


Try a military Radio& TV station (AFRTS) where nothing was
documented. After 20& years of equipment being moved around or replaced,
it was a nightmare. I had the master monitor fail one night, but
couldn't disconnect it, because the main transmitter was at the end of
that loop. They had a nice set of Grass Valley video DAs, but only used
one of the four outputs on each. Add to that, some video connectors
were BNC, and others were PL-259 since the station was built during the
time manufacturers used both.

I got fed up with intermittent cables, so one Saturday I ran a
temporary cable from the film chain strait to the transmitter and
started pulling out dead cables. The 12" * 18" cable tray was full when
I started. When I finished, the bundle was under 6" and several
thousand feet of dead cable were laying in the corner of the transmitter
& control room. That master monitor had seven pieces of coax between it
and the video switcher. There was over 100 abandoned cables I pulled
out. Most had one bad connector, and some had both bad. The other
engineer walked in and almost fainted, but I had everything in place in
time for or noon newscast, and finished everything else before my 20
hour shift ended.


They had the audio board fail in the TV control room at one time, so
they extended all the lines to the radio station's audio console and
used the preview output to feed the TV transmitter. When they got the
board back from the AFRTS service depot, they left the extra wire
connected. You could see radio station's the AM modulation in the video
baseband, from the ground loop that mess caused.


My Chief Engineer cracked up when I mentioned that "there is something
fundamentally wrong with any job that requires knee pads and a
squeeze-bottle of (cable) lube."


Just be glad it was run above the ceiling, under a metal roof. It
was rarely comfortable up there, It was either below zero, or in the 90+
degree range.



Still, by the time I was finished, the digital stuff was in and the
analog stuff (at least that which we no longer needed) was out. I even
built a set of shelves in the basement to hold the obsolete analog
equipment we hadn't sold or scrapped yet, and I carried the stuff down
and filled those shelves.


Digital? We were B&W, and the only ICs were RTL.
(Resistor-Transistor-Logic) ;-)


It was an interesting two years at that station, and then they laid off
more than half the staff, myself included. Ah, such is life.

Those cables were installed well, labeled well, and documented well.
And a lot of equipment that wasn't working, was, by the time I was done.


I built a mobile production van for WACX in the late '80s. I used
about 50 feet of clear heat shrink.


And now I'm a college student on the Dislocated Worker plan.

I imagine I'm in good company here.


Not me. The VA has decided that I'll never work again, and it drives
me crazy.


That all sounds kinda familiar, somehow...
And yeah, those PL-259 video connectors kept unscrewing themselves.
First place to look, for a bad ground connection, especially if somebody
had screwed a BNC adapter onto it. I've been in this line of work for
about 30 years, so I've seen a few of those. Sometimes you'd see
adapters on adapters. I called that a "Stack-o-dapters".

Well, this thread is getting a little long and off-topic. I'll sign off
here.

On Sat, 15 May 2010 16:44:42 -0400, "Michael A. Terrell"
wrote:


I prefer full heat for that job. I just keep it a little further
away from the board. I see less damage to boards that way. I used to
have a 6" solder pot that I would float a scrap board on, then use a
pair of pliers on the corner to smack it against something to eject all
the molten solder. I recycled thousands of 256 kb memory ICs back in
the '80s at $2.75 each. There was a huge shortage of new ICs, so they
sold as fast as I could pull them and re-tin the leads.

Well, the other day I got a new heat gun... Tried it out today, had
this nice dial on the end to set your heat, everything looked nice.

Plugged it in, turned it on, and dialed the heat up and "POP" was what
I heard! oops.

Testing showed me that it was putting out about enough heat to warm my
hand if I held it about four inches from the outlet!

Crap, I hate fixing new stuff, but took it apart, and the SCR in the
dial mechanism had a bad solder joint. New... Of course, chinese crap
made, and I did fix it.

In article ,
PeterD wrote:
Crap, I hate fixing new stuff, but took it apart, and the SCR in the
dial mechanism had a bad solder joint. New... Of course, chinese crap
made, and I did fix it.

I make a point of never buying crap tools - it simply isn't worth it. Got
quite a few Chinese made which are very good - and incredible value.

If I did buy one which didn't work I'd take it back for a refund or
exchange.

--
*Do infants enjoy infancy as much as adults enjoy adultery?

Dave Plowman London SW
To e-mail, change noise into sound.

PeterD wrote:

On Sat, 15 May 2010 16:44:42 -0400, "Michael A. Terrell"
wrote:


I prefer full heat for that job. I just keep it a little further
away from the board. I see less damage to boards that way. I used to
have a 6" solder pot that I would float a scrap board on, then use a
pair of pliers on the corner to smack it against something to eject all
the molten solder. I recycled thousands of 256 kb memory ICs back in
the '80s at $2.75 each. There was a huge shortage of new ICs, so they
sold as fast as I could pull them and re-tin the leads.

Well, the other day I got a new heat gun... Tried it out today, had
this nice dial on the end to set your heat, everything looked nice.

Plugged it in, turned it on, and dialed the heat up and "POP" was what
I heard! oops.

Testing showed me that it was putting out about enough heat to warm my
hand if I held it about four inches from the outlet!

Crap, I hate fixing new stuff, but took it apart, and the SCR in the
dial mechanism had a bad solder joint. New... Of course, chinese crap
made, and I did fix it.


Good for you!

On Mon, 17 May 2010 00:28:47 +0100, "Dave Plowman (News)"
wrote:

In article ,
PeterD wrote:
Crap, I hate fixing new stuff, but took it apart, and the SCR in the
dial mechanism had a bad solder joint. New... Of course, chinese crap
made, and I did fix it.

I make a point of never buying crap tools - it simply isn't worth it. Got
quite a few Chinese made which are very good - and incredible value.

If I did buy one which didn't work I'd take it back for a refund or
exchange.

Agreed, but it was something I picked up from a store that was going
out of business... It sat in the box for a while, and I decided to try
it yesterday.

In article ,
mm wrote:

On Mon, 10 May 2010 16:24:04 +0000 (UTC), "Geoffrey S. Mendelson"
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.


A cheap and easy way is to buy a hair dryer from one of the thrift shops
- probably cost you a $1 or so, and does the job.

David

In article ,
(Mark Zenier) wrote:

In article ,
Geoffrey S. Mendelson 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.


Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)

I haven't tried it, but I reckon you could get an old pair of pliers -
heat em up on the stove then gently grip the heat shrink with the hot
jaws - might be worth a try

David

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.

You can buy small butane-powered torches, with a variety of tips. The
one I bought has a flame tip, a catalytic-heater soldering tip, and a
catalytic-heater hot-air jet. The latter works very well for doing
small heat-shrinking jobs - with the torch turned down to minimum gas
flow it produces a rather delicate and controllable jet of hot air
which can heat the tubing without roasting things nearby.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!