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Resistance soldering

jhoff02@...
 

hope this is the correct place to post. I have several hon3 brass engine and parts either brake of or become unsoldered. When I try to solder them with regular iron gets too hot and other  parts come lose. So think I need resistance soldering iron but know how much watts to get. Micro mart has a 100watt for about $400. Is that enough or do in need more watts. Have no plans to build brass engine. Jim

kevin b
 

an old trick I use from time to time is get some cloth and soak it in water. put the wet cloth (not so wet water is drippng out) all around everything near the part you're putting on.
the wet cloth keeps the things you DON'T want to come unsoldered cool and they stay put.
hope this helps a little.

Kevin.

I have several hon3 brass engine and parts either brake of or become unsoldered. When I try to solder them with regular iron gets too hot and other parts come lose.

Robert Bell
 

Jim,

Get some Tix solder and Tix flux before shelling out $400.  Tix is low melt temp, high strength.

Clean brass parts - a fibreglass brush works great.
Cut a TINY sliver off of Tix solder sitck with a sharp hobby knife. Position parts.
Apply Tix flux.
With the sharp point of hobby knife gently stab the sliver and place next to joint.
Apply heat carefully to melt solder and for it to pull into joint.

You might try a pencil torch available from hobby shops, Harbor Freight, Northern Tool, etc...

I'm not saying don't get a resist unit, I have two, but I rarely use them. 

Rob Bell
Waynesville,  NC

Pete C
 

If you wind up deciding you want a resistance unit, I actually have two, get at least a 200 watt unit.  It will heat joints much more quickly and it will be much more versatile.  
  PBL and American Beauty are a couple of really quality units.  
  I use the probe a lot more often than the tweezers but they do have their uses since you can isolate the heat in specific areas.  
  I also have several solders with different melting points as this allows easier assembly of parts in close proximity.  The use of wet tissue paper placed strategically around the heated area also does a tremendous job of pulling the heat away from areas you want to stay put.
  Also VERY important is to be sure the area to be soldered is CLEAN.  If it’s not you will never get a solid joint even with flux.  I also recommend Tix flux for metal work but since it’s an acid flux DO NOT use it on any electrical work including track work.

Hope this helps a little with your current dilemma. 

Pete

On Sep 25, 2019, at 9:46 AM, Robert Bell via Groups.Io <ionhoss@...> wrote:

Jim,

Get some Tix solder and Tix flux before shelling out $400.  Tix is low melt temp, high strength.

Clean brass parts - a fibreglass brush works great.
Cut a TINY sliver off of Tix solder sitck with a sharp hobby knife. Position parts.
Apply Tix flux.
With the sharp point of hobby knife gently stab the sliver and place next to joint.
Apply heat carefully to melt solder and for it to pull into joint.

You might try a pencil torch available from hobby shops, Harbor Freight, Northern Tool, etc...

I'm not saying don't get a resist unit, I have two, but I rarely use them. 

Rob Bell
Waynesville,  NC

Brian Kopp
 

I have an American Beauty resistance soldering station and 2 Weller thermal irons plus a bunch of other soldering tools. However, I use soldering in my work as a consulting electrical engineer.

My resistance station uses a probe and alligator clip style rather than the 2-prong handle style.

I try to use only eutectic solders that do not have that interim pastey phase that creates poor, incomplete solder joints. Eutectic solders go from solid to liquid.

Sn63/Pb37 solder has been my first choice for eutectic lead solder since the 80s when NASA taught me basic soldering (not flight soldering). It melts at 183C.

For lead-free eutectic solder Sn96.5/Ag3.5 is a common choice. But it melts at 221C.

If you really want to get the temperature down (to solder pewter and some higher temperature white metal alloys), Try Indium/Tin solder. Chipquick is a brand. Their (lead-free) In52/Sn48 solder is also eutectic and melts at 118C. It is excellent for thermal soldering small surface mount components like LEDs too, for those headlights. Its expensive but they sell it in small 10' long pieces for about $20 or less. They have a matching flux they sell with this solder because the solder does not have a flux core. The Chipquick flux is SMD291. 


Pick a flux that matches the solder manufacturers suggestions. If I can, I use organic-acid, water-based flux. The cleanup is easy. Kester and others have lead and lead-free solders that are organic-acid flux core. There are also No-Clean fluxes like the SMD291 flux from Chipquick. Just make sure any additional flux you use matches the solder, especially if it is flux-core solder.....

Clean everything first. Dirt and corrosion make excellent insulators and must be removed before the solder will adhere. 

Test solder first if you can with scrap pieces. You need to dial in the iron temperature (or % output for a resistance station)  to match the set-up. For thermal irons, the iron temp setting will be higher than the solder melting point because the thermal mass of the widgets you are soldering will wick away heat from the iron.

Hope that helps,

Regards,
Brian Kopp
Jacksonville, FL


 

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Brian Kopp
Jacksonville, FL

Brian Kopp
 

Sorry for the typo. Try "Chipquik" low temperature solder and flux. Not "chipquick"......
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Brian Kopp
Jacksonville, FL

Mick Moignard
 

Another option is just to use a larger - higher wattage - regular soldering iron.  I wouldn’t go anywhere near a brass model an iron smaller than 50watt, and regularly use a 75watt with a large bit (large=lots of heat capacity).  You need lots of instant heat so that you can heat up and make the joint before the heat spreads to nearby joints. Basically you need to overwhelm it with localised heat. And I mean heat, and not temperature here.  

But for most work, I do use an RSU merely because it is so much faster; many brass repairs with it are in and out, done, in a couple of seconds, and long before there is enough heat in there to spread to other nearby joints.

Mick

________________________________
Mick Moignard
m: +44 7774 652504
Skype: mickmoignard

, so please excuse the typos.