# Choosing a general-purpose soldering gun

W

#### wylbur37

Jan 1, 1970
0
When I was a teenager, I purchased a Weller 8200 dual-heat (100/140
watt) soldering gun. It served me well over the years. Then about ten
years ago, I went through a period where I didn't need to do any
soldering and decided to give it away as part of "uncluttering". (I
later realized that was a mistake).

Now, I need to do some soldering again and need a soldering gun. I
could purchase a new Weller 8200 through mail-order, which will cost
over $40. (I could also get one used via eBay for as low as$8, but I
don't trust buying used stuff from strangers).

I could also purchase a new soldering gun at Radio Shack, either a
dual-heat (150/230 watt) model (Cat. No. 64-2187) for $29.99, or a single-heat (100 watt) model (Cat. No. 64-2193) for$12.99.

If I recall correctly, back when I still had my Weller 8200, the first
heat setting (100 watts) was usually enough for most wiring jobs. Very
rarely did I have to click it back to the second position (140 watts)
except to solder some thicker metal items.

I'm currently leaning towards getting the Radio Shack 100 watt model,
not only to save money but because the heavier model (150/230 watt) is
probably too hot anyway and might burn out some components. Another
reason I'm leaning towards getting the Radio Shack one is that there
are numerous Radio Shack retail stores near where I live (in New York
City) and I could just go and buy one over-the-counter without the
hassle of waiting for it to be delivered. (As for the Weller 8200,
it's more expensive and I don't know which stores in New York City
would sell it anyway).

I was wondering what your thoughts were on ...

a. whether 100 watts is sufficient for most soldering jobs
(involving ordinary stuff like LEDs, resistors, etc.).

guns mentioned above and whether you think they're any good.

c. whether you know of any retail stores in the New York City area
that sell a Weller 8200 soldering gun for $30 or less. Thanks for your help. M #### Michael A. Covington Jan 1, 1970 0 A gun or an iron? By "gun" I assume you mean the device, invented by Carl Weller, that heats up quickly by driving a huge current through a wire tip. (It contains a big transformer, and you can feel it buzzing a little as you use it.) By "iron" I mean something with the heating element separate from the tip. a. whether 100 watts is sufficient for most soldering jobs (involving ordinary stuff like LEDs, resistors, etc.). It is way too much. If you are working with small components, the best soldering instrument is a temperature-controlled iron (not gun) of maybe 15 to 25 watts. By temperature-controlled I mean that they contain a thermostat or temperature sensor to maintain a uniform 700 degrees F (or various others; on printed circuit boards I use a lower temperature). Because of the temperature control, an iron of this type heats up rapidly (in about 1 minute); it runs at full power until working temperature is reached, then automatically cuts back its power. A soldering *gun* is for appliance repair, heavy automotive wiring, and the like. I know that back in the 1960s, people used to use soldering guns with small components (which were bigger back then), but it's not easy. b. whether you've had any experience using the Radio Shack soldering guns mentioned above and whether you think they're any good. Don't know.$70 will buy you a temperature-controlled iron from Radio Shack, the
64-2185, that should be a pleasure to use. (I haven't tried it; I use a
Weller station that I bought secondhand at a hamfest.)

Radio Shack also has some irons in the 15- to 30-watt range that are not
temperature controlled. The 64-2051, at $8, looks good for work with small components. They do have an iron with a gun-shaped handle, just to confuse you. Radio Shack is of course catering to the hobbyist market. For industrial-quality soldering irons, look at: http://www.mouser.com/catalog/618/1261.pdf http://www.mouser.com/catalog/618/1262.pdf The Weller WES50 and WESD10 are temperature-controlled, like what I use. The WTCPT is also very good (it has a thermostat built into the iron, but no adjustments or display). Weller's "economical" soldering station is not temperature-controlled, but lets you vary the power (which is not nearly as handy). c. whether you know of any retail stores in the New York City area that sell a Weller 8200 soldering gun for$30 or less.

For an old-fashioned Weller soldering gun (a tool that certainly has its
place) I'd try Wal-Mart or K-Mart.

C

#### CFoley1064

Jan 1, 1970
0
Subject: Choosing a general-purpose soldering gun
From: [email protected] (wylbur37)
Date: 4/22/2004 6:10 AM Central Standard Time
Message-id: <[email protected]>

When I was a teenager, I purchased a Weller 8200 dual-heat (100/140
watt) soldering gun. It served me well over the years. Then about ten
years ago, I went through a period where I didn't need to do any
soldering and decided to give it away as part of "uncluttering". (I
later realized that was a mistake).

Now, I need to do some soldering again and need a soldering gun. I
could purchase a new Weller 8200 through mail-order, which will cost
over $40. (I could also get one used via eBay for as low as$8, but I
don't trust buying used stuff from strangers).

I could also purchase a new soldering gun at Radio Shack, either a
dual-heat (150/230 watt) model (Cat. No. 64-2187) for $29.99, or a single-heat (100 watt) model (Cat. No. 64-2193) for$12.99.

If I recall correctly, back when I still had my Weller 8200, the first
heat setting (100 watts) was usually enough for most wiring jobs. Very
rarely did I have to click it back to the second position (140 watts)
except to solder some thicker metal items.

I'm currently leaning towards getting the Radio Shack 100 watt model,
not only to save money but because the heavier model (150/230 watt) is
probably too hot anyway and might burn out some components. Another
reason I'm leaning towards getting the Radio Shack one is that there
are numerous Radio Shack retail stores near where I live (in New York
City) and I could just go and buy one over-the-counter without the
hassle of waiting for it to be delivered. (As for the Weller 8200,
it's more expensive and I don't know which stores in New York City
would sell it anyway).

I was wondering what your thoughts were on ...

a. whether 100 watts is sufficient for most soldering jobs
(involving ordinary stuff like LEDs, resistors, etc.).

guns mentioned above and whether you think they're any good.

c. whether you know of any retail stores in the New York City area
that sell a Weller 8200 soldering gun for $30 or less. Thanks for your help. The right tool for the job. Use a soldering iron for PC boards and small work, and a gun for the big jobs. If you need to do the Radio Shack thing, your best bet for electronics might be the "Soldering Work Station with Dual-Powered Iron", RS p/n 64-2184. It's$21.99, and has a built-in stand and sponge and a
dual temp setup (diode with switch) to give you 20 or 40 watts.

Having said that, the Weller is a good gun, and worth the price. Of course,
you'll have to replace the tips, but they're consumables, anyway. A reliable
beast. You can also get replacement parts from the manufacturer. A reputable
eBay seller wouldn't deliberately risk negative feedback over something that
small.

Neither of the two Radio Shack guns you're looking at are the best choice,
although they'll do in a pinch. The one I used a number of years back got
rather hot to hold after a bit of use.

If you're going to use it frequently, you need to pump a lot of heat for a long
period of time, or if the difference between adequate and good is important to
you, the Weller is worth it. If you want something cheap, go to

http://www.harborfreight.com/

They have two cheapies (150 and 185 watts) for 10 bucks each. No guarantees
there.

Good luck
Chris

P

#### Phil Hobbs

Jan 1, 1970
0
Michael said:
A gun or an iron? By "gun" I assume you mean the device, invented by Carl
Weller, that heats up quickly by driving a huge current through a wire tip.
(It contains a big transformer, and you can feel it buzzing a little as you
use it.) By "iron" I mean something with the heating element separate from
the tip.

It is way too much. If you are working with small components, the best
soldering instrument is a temperature-controlled iron (not gun) of maybe 15
to 25 watts. By temperature-controlled I mean that they contain a
thermostat or temperature sensor to maintain a uniform 700 degrees F (or
various others; on printed circuit boards I use a lower temperature).

Because of the temperature control, an iron of this type heats up rapidly
(in about 1 minute); it runs at full power until working temperature is
reached, then automatically cuts back its power.

A soldering *gun* is for appliance repair, heavy automotive wiring, and the
like. I know that back in the 1960s, people used to use soldering guns with
small components (which were bigger back then), but it's not easy.

Don't know.

$70 will buy you a temperature-controlled iron from Radio Shack, the 64-2185, that should be a pleasure to use. (I haven't tried it; I use a Weller station that I bought secondhand at a hamfest.) Radio Shack also has some irons in the 15- to 30-watt range that are not temperature controlled. The 64-2051, at$8, looks good for work with small
components.

They do have an iron with a gun-shaped handle, just to confuse you.

Radio Shack is of course catering to the hobbyist market. For
industrial-quality soldering irons, look at:
http://www.mouser.com/catalog/618/1261.pdf
http://www.mouser.com/catalog/618/1262.pdf
The Weller WES50 and WESD10 are temperature-controlled, like what I use.
The WTCPT is also very good (it has a thermostat built into the iron, but no
adjustments or display). Weller's "economical" soldering station is not
temperature-controlled, but lets you vary the power (which is not nearly as
handy).

For an old-fashioned Weller soldering gun (a tool that certainly has its
place) I'd try Wal-Mart or K-Mart.
Soldering guns are great for connecting metal shields and heavy wires to
ground planes, e.g. in a dead-bug RF prototype. They cool down much
faster than a Godzilla soldering iron, which is the other good method

Cheers,

Phil Hobbs

M

#### mike

Jan 1, 1970
0
wylbur37 said:
When I was a teenager, I purchased a Weller 8200 dual-heat (100/140
watt) soldering gun. It served me well over the years. Then about ten
years ago, I went through a period where I didn't need to do any
soldering and decided to give it away as part of "uncluttering". (I
later realized that was a mistake).

Now, I need to do some soldering again and need a soldering gun. I
could purchase a new Weller 8200 through mail-order, which will cost
over $40. (I could also get one used via eBay for as low as$8, but I
don't trust buying used stuff from strangers).

I could also purchase a new soldering gun at Radio Shack, either a
dual-heat (150/230 watt) model (Cat. No. 64-2187) for $29.99, or a single-heat (100 watt) model (Cat. No. 64-2193) for$12.99.

If I recall correctly, back when I still had my Weller 8200, the first
heat setting (100 watts) was usually enough for most wiring jobs. Very
rarely did I have to click it back to the second position (140 watts)
except to solder some thicker metal items.

I'm currently leaning towards getting the Radio Shack 100 watt model,
not only to save money but because the heavier model (150/230 watt) is
probably too hot anyway and might burn out some components. Another
reason I'm leaning towards getting the Radio Shack one is that there
are numerous Radio Shack retail stores near where I live (in New York
City) and I could just go and buy one over-the-counter without the
hassle of waiting for it to be delivered. (As for the Weller 8200,
it's more expensive and I don't know which stores in New York City
would sell it anyway).

I was wondering what your thoughts were on ...

a. whether 100 watts is sufficient for most soldering jobs
(involving ordinary stuff like LEDs, resistors, etc.).

guns mentioned above and whether you think they're any good.

c. whether you know of any retail stores in the New York City area
that sell a Weller 8200 soldering gun for $30 or less. Thanks for your help. A GUN is great if you need high temperature with low thermal mass infrequently. Like when you want to solder a wire onto a tube socket. For current electronic work, they're obsolete. Get a Weller (or any one of a zillion similar brands) temperature controlled iron and be done with it. Ham radio swap meets are good places to get used/refurbished ones. Going price is around$40. I can put you in touch with a trusted refurbished one if you like.

For small stuff, Antex makes a 15W iron that works nicely for normal
components on a circuit board. Does a credible job on Surface Mount
with the right tip.

For heavy electronic soldering you're gonna want
an Ungar 47W 1050degree iron. Lots of thermal mass, but not huge like
the one you used in shop class 40 years ago. Put it on a light dimmer
and it will work over a wide range of applications.
mike

--
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ D #### Dave VanHorn Jan 1, 1970 0 Soldering guns are great for connecting metal shields and heavy wires to ground planes, e.g. in a dead-bug RF prototype. They cool down much faster than a Godzilla soldering iron, which is the other good method I've been spending the last couple days doing fine pitch SMD soldering, and soldering shield cans and removing 100W VHF and UHF transistors.. One iron, two different tips. Go Metcal! E #### [email protected] Jan 1, 1970 0 wylbur37 said: When I was a teenager, I purchased a Weller 8200 dual-heat (100/140 watt) soldering gun. It served me well over the years. Then about ten years ago, I went through a period where I didn't need to do any soldering and decided to give it away as part of "uncluttering". (I later realized that was a mistake). Now, I need to do some soldering again and need a soldering gun. I could purchase a new Weller 8200 through mail-order, which will cost over$40. (I could also get one used via eBay for as low as $8, but I don't trust buying used stuff from strangers). I could also purchase a new soldering gun at Radio Shack, either a dual-heat (150/230 watt) model (Cat. No. 64-2187) for$29.99, or a
single-heat (100 watt) model (Cat. No. 64-2193) for $12.99. If I recall correctly, back when I still had my Weller 8200, the first heat setting (100 watts) was usually enough for most wiring jobs. Very rarely did I have to click it back to the second position (140 watts) except to solder some thicker metal items. I'm currently leaning towards getting the Radio Shack 100 watt model, not only to save money but because the heavier model (150/230 watt) is probably too hot anyway and might burn out some components. Another reason I'm leaning towards getting the Radio Shack one is that there are numerous Radio Shack retail stores near where I live (in New York City) and I could just go and buy one over-the-counter without the hassle of waiting for it to be delivered. (As for the Weller 8200, it's more expensive and I don't know which stores in New York City would sell it anyway). I was wondering what your thoughts were on ... a. whether 100 watts is sufficient for most soldering jobs (involving ordinary stuff like LEDs, resistors, etc.). b. whether you've had any experience using the Radio Shack soldering guns mentioned above and whether you think they're any good. c. whether you know of any retail stores in the New York City area that sell a Weller 8200 soldering gun for$30 or less.

For the stuff you mentioned - LEDs, resistors, etc
get a cheap soldering iron or pencil from Radio Shack
like catalog #'s 64-2071, 64-2070 or 62-2067

Later on, you may want to chose a fancy iron with
grounded tip and heat control - but the Radio Shack

W

#### wylbur37

Jan 1, 1970
0
Most people who responded to my original posting tend to agree that I
wouldn't need more than a a 100-watt soldering tool for most casual
soldering of LEDs and resistors. Some have even recommended using
soldering tools as low as 15 watts.

Now, I've been reluctant to use a low-wattage soldering device
because of the following reason ...

With a high-wattage tool, I only need to hold it against the
connecting wire for a short time before the spot on the wire that
touches the heating tip gets hot enough to melt the solder. Once the
solder melts and flows over the wire, I pull the soldering tool away.
On the other hand, with a low-wattage tool, it takes longer for the
connecting wire to heat up, and that extra time may allow heat to
travel along the wire and "cook" or otherwise damage the component.
So it's actual "safer" to use a higher-wattage soldering tool than a
low-wattage one, as long as you know well enough to pull it away in time.

Is there any flaw in my logic here?

D

#### Dave VanHorn

Jan 1, 1970
0
So it's actual "safer" to use a higher-wattage soldering tool than a
low-wattage one, as long as you know well enough to pull it away in time.

Is there any flaw in my logic here?

No. The ideal iron has a tightly controlled temperature, but loads of
thermal mass, and good heat delivery to the tip.

The tips should be iron plated, so that they don't leach into the solder
like copper does, and end up becoming sharp needles to gouge the PCB.

The 40W weller iron with a 700 degree tip is an excellent starting point.

I went the small iron route, but because of their tiny thermal mass and poor

In this field, your soldering iron, and your meter are pretty much your
primary tools.
Don't skimp on them.

E

#### exray

Jan 1, 1970
0
wylbur37 said:
Most people who responded to my original posting tend to agree that I
wouldn't need more than a a 100-watt soldering tool for most casual
soldering of LEDs and resistors. Some have even recommended using
soldering tools as low as 15 watts.

Now, I've been reluctant to use a low-wattage soldering device
because of the following reason ...

With a high-wattage tool, I only need to hold it against the
connecting wire for a short time before the spot on the wire that
touches the heating tip gets hot enough to melt the solder. Once the
solder melts and flows over the wire, I pull the soldering tool away.
On the other hand, with a low-wattage tool, it takes longer for the
connecting wire to heat up, and that extra time may allow heat to
travel along the wire and "cook" or otherwise damage the component.
So it's actual "safer" to use a higher-wattage soldering tool than a
low-wattage one, as long as you know well enough to pull it away in time.

Is there any flaw in my logic here?

Its not so much the wattage as the physical contact to the connection.
I don't know that a 100 watt Weller gun gets any hotter than a 25-40w
soldering pencil.

I do mostly tube work and use a Weller 40 watt pencil with a 1/4" chisel
type tip. As far as I'm concerned it works better than my Weller gun
for normal component terminal connections...because of the wide tip.

Direct chassis connections are a bit different because the chassis
will act as a heatsink and the little pencil can't keep up as well as
the 100 w gun. However, a 40 watt pencil isn't going to bog down on a
terminal strip or tube socket full of wires.

This 40w with a big tip is TOO big for PCB work. I have a 25w pencil
with a pointed tip for that work.

HTH,
Bill

M

#### Michael A. Covington

Jan 1, 1970
0
wylbur37 said:
Most people who responded to my original posting tend to agree that I
wouldn't need more than a a 100-watt soldering tool for most casual
soldering of LEDs and resistors. Some have even recommended using
soldering tools as low as 15 watts.

Now, I've been reluctant to use a low-wattage soldering device
because of the following reason ...

With a high-wattage tool, I only need to hold it against the
connecting wire for a short time before the spot on the wire that
touches the heating tip gets hot enough to melt the solder. Once the
solder melts and flows over the wire, I pull the soldering tool away.
On the other hand, with a low-wattage tool, it takes longer for the
connecting wire to heat up, and that extra time may allow heat to
travel along the wire and "cook" or otherwise damage the component.
So it's actual "safer" to use a higher-wattage soldering tool than a
low-wattage one, as long as you know well enough to pull it away in time.

Is there any flaw in my logic here?

No, but a well-designed 15-watt iron is enough for modern small components.
3 watts would not be.

A temperature-controlled iron is best, because it kicks in extra power as
soon as you apply it to something that starts drawing heat out of it. It
handles like a much more powerful iron (because of the power in reserve) but
does not overheat things.

M

#### Michael A. Covington

Jan 1, 1970
0
I should add that for successful soldering, you have to develop a sense of
timing.

As soon as you apply the iron to a joint, heat is drawn out of it.

If you try to solder several joints in succession, and the iron isn't
temperature-controlled, it will gradually cool down. You'll have to apply
it to the joints longer and longer, and because this provides time for heat
conduction, you'll overheat the components.

With experience, you determine the right pace.

E

#### [email protected]

Jan 1, 1970
0
wylbur37 said:
Most people who responded to my original posting tend to agree that I
wouldn't need more than a a 100-watt soldering tool for most casual
soldering of LEDs and resistors. Some have even recommended using
soldering tools as low as 15 watts.

Now, I've been reluctant to use a low-wattage soldering device
because of the following reason ...

With a high-wattage tool, I only need to hold it against the
connecting wire for a short time before the spot on the wire that
touches the heating tip gets hot enough to melt the solder. Once the
solder melts and flows over the wire, I pull the soldering tool away.
On the other hand, with a low-wattage tool, it takes longer for the
connecting wire to heat up, and that extra time may allow heat to
travel along the wire and "cook" or otherwise damage the component.
So it's actual "safer" to use a higher-wattage soldering tool than a
low-wattage one, as long as you know well enough to pull it away in time.

Is there any flaw in my logic here?

There is. It includes a hidden assumption that the lower
wattage tool is too small. When you use a properly sized
iron for the job, going to a higher wattage provides no
practical increase in the safety to which you refer.
But it does include some drawbacks.

A higher wattage tool is generally physically heavier and
bulkier than a low wattage tool. A gun is definitely
harder to control than a small iron or soldering pencil.
A 100 watt iron or gun is WAY more than you need for what
you mentioned. Using it may be hiding a problem. If you need
100 watts to solder an LED, you are doing something wrong.
If you can't solder an LED with a 25 watt iron, you are doing
something wrong. A 25 watt iron will not overheat an LED,
unless you are doing something wrong.

W

#### wylbur37

Jan 1, 1970
0
... a hidden assumption that the lower
wattage tool is too small. When you use a properly sized
iron for the job, going to a higher wattage provides no
practical increase in the safety to which you refer.
But it does include some drawbacks.

A higher wattage tool is generally physically heavier and
bulkier than a low wattage tool. A gun is definitely
harder to control than a small iron or soldering pencil.
A 100 watt iron or gun is WAY more than you need for what
you mentioned. Using it may be hiding a problem. If you need
100 watts to solder an LED, you are doing something wrong.
If you can't solder an LED with a 25 watt iron, you are doing
something wrong. A 25 watt iron will not overheat an LED,
unless you are doing something wrong.

I'm not disagreeing with anything you just said.

However, I wish to point out (just to be a P.I.T.A. that there are
pragmatic reasons for doing things that might not otherwise be done in
theory. So, despite the fact that someone might not *need* to use more
than a 25-watter to solder an LED, they might still use a 100-watter
anyway. Why? Because in the real world, not everyone has the budget to
afford purchasing more than one soldering tool for different size jobs
(nor have the physical space to keep more than one). Therefore, they
would select a "general-purpose" soldering tool and try to use that
for "everything" to the extent possible. (Doesn't sound very
"professional", but then not everyone on this group has to be a
"pro").

M

#### Michael A. Covington

Jan 1, 1970
0
I'm not disagreeing with anything you just said.

However, I wish to point out (just to be a P.I.T.A. that there are
pragmatic reasons for doing things that might not otherwise be done in
theory. So, despite the fact that someone might not *need* to use more
than a 25-watter to solder an LED, they might still use a 100-watter
anyway. Why? Because in the real world, not everyone has the budget to
afford purchasing more than one soldering tool for different size jobs
(nor have the physical space to keep more than one). Therefore, they
would select a "general-purpose" soldering tool and try to use that
for "everything" to the extent possible. (Doesn't sound very
"professional", but then not everyone on this group has to be a
"pro").

This raises the interesting question of how to modify the tip of a Weller
soldering gun to be small enough for circuit-board work. I seem to recall
having seen some trick with a sharpened piece of #14 wire, or something like
that.

K

#### Ken Weitzel

Jan 1, 1970
0
Michael said:
This raises the interesting question of how to modify the tip of a Weller
soldering gun to be small enough for circuit-board work. I seem to recall
having seen some trick with a sharpened piece of #14 wire, or something like
that.

In a real pinch, fasten a common pin to your tip by
tying it on with a couple of pieces of solid hook-up
wire. Tighten the wire by twisting the ends with your
pliers.

Use the pointed end for tiny things, like dip connections,
the heavy end for regular pcb connections.

Ken

M

#### mike

Jan 1, 1970
0
wylbur37 said:
Most people who responded to my original posting tend to agree that I
wouldn't need more than a a 100-watt soldering tool for most casual
soldering of LEDs and resistors. Some have even recommended using
soldering tools as low as 15 watts.

Now, I've been reluctant to use a low-wattage soldering device
because of the following reason ...

With a high-wattage tool, I only need to hold it against the
connecting wire for a short time before the spot on the wire that
touches the heating tip gets hot enough to melt the solder. Once the
solder melts and flows over the wire, I pull the soldering tool away.
On the other hand, with a low-wattage tool, it takes longer for the
connecting wire to heat up, and that extra time may allow heat to
travel along the wire and "cook" or otherwise damage the component.
So it's actual "safer" to use a higher-wattage soldering tool than a
low-wattage one, as long as you know well enough to pull it away in time.

Is there any flaw in my logic here?

Don't confuse thermal mass with watts.
I categorize irons into three categories, best first.

1) Metcal makes an iron that's RF driven. It can put a LOT of watts
into a small tip almost instantly to keep the temperature constant.
The tip can be just hot enough to melt the solder, small enough to get
into a tight space and supply enough power to keep the temperature
stable over a wide range of joint sizes (load thermal mass). Once
you've tried one, you'll never want to go back. For personal use,
the fatness of your wallet is a factor in obtaining one.

2) Weller makes temperature controlled irons of various types.
The coupling between the tip and the source power is looser than
with a Metcal. But you still get pretty good soldering at relatively
low temperatures.

3) Uncontrolled irons. These rely on power and thermal mass to do the
job. Big iron with low watts can work over a wide range of load mass
if it's big enough. Small tipped iron has to get way too hot because
of low thermal mass. So, it's too hot on tiny parts and too cold on big
parts. But you can still get there if you size the iron to the job.
I have a 1050 degree 47 Watt Ungar for the big jobs. Big ole tip, lotsa
thermal masss and a light dimmer to control the temperature for the job.

One thing I haven't seen mentioned so far about guns is the BIG ole
inductive spike you get when you let go of the trigger. Theoretically,
this could be isolated from the tip. Is it in practice?? Big guns
were invented long before people tried to solder SMT fets.

mike

--
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ D #### Dave VanHorn Jan 1, 1970 0 1) Metcal makes an iron that's RF driven. It can put a LOT of watts into a small tip almost instantly to keep the temperature constant. The tip can be just hot enough to melt the solder, small enough to get into a tight space and supply enough power to keep the temperature stable over a wide range of joint sizes (load thermal mass). Once you've tried one, you'll never want to go back. For personal use, the fatness of your wallet is a factor in obtaining one. Excellent iron, about$200 on ebay, look for the SP-200.
I reccomend a 1/8" chisel, a narrow chisel, and a curved pinpoint tip, at
600 or 700 degrees.

Also, 63/37 solder only!

2) Weller makes temperature controlled irons of various types.
The coupling between the tip and the source power is looser than
with a Metcal. But you still get pretty good soldering at relatively
low temperatures.

Very nice, \$120-ish
3) Uncontrolled irons. These rely on power and thermal mass to do the
job. Big iron with low watts can work over a wide range of load mass
if it's big enough. Small tipped iron has to get way too hot because
of low thermal mass. So, it's too hot on tiny parts and too cold on big
parts. But you can still get there if you size the iron to the job.
I have a 1050 degree 47 Watt Ungar for the big jobs. Big ole tip, lotsa
thermal masss and a light dimmer to control the temperature for the job.

Good as a backup iron, I have one at a repeater site, in case I need it.
One thing I haven't seen mentioned so far about guns is the BIG ole
inductive spike you get when you let go of the trigger. Theoretically,
this could be isolated from the tip. Is it in practice?? Big guns
were invented long before people tried to solder SMT fets.

Big guns are for soldering shield cans, if I ever find one that the metcal
can't handle with the fat tip.

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