You're welcome. If you can read the label on the old spool, see if
you can find the same alloy & gauge. I've had way too many labels fall
off spools before they were empty. I do have a bunch of empty orange
1Lb spools I collected whiile I worked at Microdyne. I managed to get
them to request them when someone in prduction needed a new spool.
Sometimes you can get a spool that's been dropped & broken, real cheap.
They are also great for 22-26 AWG hookup wire. :)
Using carbon electrodes will limit the maximum current through the
joint. You'd need a higher voltage to do much more that what the
Alkalines will do. The only advantage of the NiMh is their output don't
drop until they are mostly discharged. The old Wahl cordless irons used
a pair of C sized NiCad and worked fairly well. The problem is that he
needs 25 Watts or more of heat for that wire size to get good wetting on
a solder joint. That would be about 5 Amps out of the battery, and the
tool was designed for lower output chemistry than NiMh.
What is the resistance between the battery terminal & the item to be
soldered? How much resistance does the switch add? What is the maximum
current the carbon will handle? How much does the resistance go up with
heat? How much waste heat can the cheap plastic case stand before it
deforms, or catches fire?
Lots of missing, but critical information. In the commercials &
photos they never showed them soldering anything heavier than a
component lead. If you want portable, use a 12V jump pack, a step up
regulator & a 24 volt soldering iron. Then you can get up to 75 Watts
of heat in a short time, and keep it hot for a long time. I'm trying to
find a decent steel ammo can around here to build a portable soldering
iron into. The battery, charger, regulator, iron holder & iron along
with room for a few spare tips, & a roll of solder. All I've found are
plastic junk. One slip of the hot iron and you'll burn a hole through
it.
Real resistance soldering is generally done with AC, and the
transformer primary was switched to minimize losses. It's closer to
spot welding than soldering. It's done at lower currents & isn't
pulsed, but both rely on fairly high currents through the joint.
I was given one - have all sorts from large black beauties down.
It is a conductive short that heats up the work - the work must
be the conductor. If the current is high enough, it gets hot and
you can melt onto the hot metal.
Remember the short must be held for a while - not moved around or
on - off.
Martin
On 1/1/2013 11:01 PM, Tom Gardner wrote:
Classic resistance soldering, scaled down to hobby level
applications. Any surface resistance of the wire prevents it from
heating at the availible current. The current has to be high enough to
heat the copper past the melting point of the solder. 14 AWG runs near
room temperature at 15 Amps. That means you'll need enough current to
heat it to around 700 F°
BTW: Here is more than you ever wanted to know about AWG copper wire:
http://library.bldrdoc.gov/docs/nbshb100.pdf
Bigger wire... Bigger soldering iron...
Solid wire absorbs more heat than stranded wire, and its harder to use
solder to transfer heat.
I have battery operated on in my tool pouch that works wonders on 18 ga or
smaller stranded with fine solder.
-- Louis L'Amour
(Amazon.com product link shortened)
Many propane torch kit used to come with a chisel point soldering
attachment like the one included above. I have one that I use for
soldering heavier gauge wire. Mine is made with a short 3/8" dia
copper chisel point rod held onto a brass holder that clamps onto the
end of a propane torch. The brass holder has holes to allow the flame
from the propane torch to exit, but still heat the copper rod. Could
be easy to make one if you can't find one second-hand.
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