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What is the proper temperature for soldering wires to a dcc decoder?

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What is the proper temperature for soldering wires to a dcc decoder?
Posted by irishRR on Sunday, September 22, 2019 4:03 PM

I just bought a nicer newer soldering iron that has a more precise tip so that I can start to do some more complex dcc decoder installs on my older n scale locos. This one has an adjustable temperature dial... my last one did not. What temperature should I set it to?

I have read horror stories about people damaging decoders from having too hot of an iron.... any advice for performing these delicate installs? I look forward to hearing. thanks.

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Posted by tstage on Sunday, September 22, 2019 4:12 PM

I set my Weller soldering station between 650-700F and that works very well for me.  I also pre-solder the board pad and stripped decoder wire and use a small (small!) dab of rosin soldering paste flux on the pad to achieve a shiny solder joint.  The key to that is to be quick with the iron and don't move the wire until the joint sets.

Tom

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Posted by wvg_ca on Sunday, September 22, 2019 5:04 PM

it depends somewhat on the solder that you use , differing solder has differing meltpoints ..

as a guide, tip temperature should be about 100 degrees f higher that the solder melt temperature, roughly 600 degrees f minimum

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Posted by BigDaddy on Sunday, September 22, 2019 5:39 PM

63/47 solder is supposed to melt @ 361F.  That's from the Internet, so maybe it's true maybe not. 

I've used the Xtronics in the upper 500's range, but that brings up another issue.  Most of us can't "calibrate" at that temperature range.  Just because you see a bright red digital readout of 550, is it really 550 or 450 or 650? 

I've never gone to 700.

Randy, Paul, Greg, Mel et.al.  to the white courtesy phone

Henry

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Posted by RR_Mel on Sunday, September 22, 2019 6:35 PM

I use 60/40 .03” diameter rosin core solder for most of my soldering needs.  My soldering station has variable temperature 392°F to 896°F, I normally keep it set to 700°F.  I use a .08” dual flat tip.  That has worked for me for more years than I want to remember.
 
For heavy duty soldering I have a 100 Watt and 250 American Beauty soldering irons and use 60/40 .06” diameter rosin core solder.
 
I recently switched from Alpha soldering paste to Quickfix soldering paste, I found out that for the last 20 years the Alpha I've been using isn’t corrosion free.
 
While working on my Arduino expansion boards I noticed that the solder wasn’t shiny after a couple of weeks and after switching to Quickfix the solder stays shiny.
 
What is the melting point of 60 40 solder?
Alloys commonly used for electrical soldering are 60/40 Sn-Pb, which melts at 188 °C (370 °F), and 63/37 Sn-Pb used principally in electrical/electronic work. This mixture is a eutectic alloy of these metals, which: has the lowest melting point (183 °C or 361 °F) of all the tin-lead alloys.
 
 
Mel
 
 
My Model Railroad   
 
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I'm beginning to realize that aging is not for wimps.
 
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Posted by tstage on Sunday, September 22, 2019 6:42 PM

Henry,

The lower the tip temperature; the longer it requires you to be in contact with the solder to melt it and the greater the chance of either melting the insulation on the wire and/or the soldering pad lifting.  600F is adequate for soldering small decoder wires and 700F isn't too high.  I wouldn't go much higher than 700F though.

Minimizing soldering time is best.  Take it FWIW from someone who skywired 30AWG wire to prototype PCBs for 4 years...

Tom

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Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by RR_Mel on Sunday, September 22, 2019 6:59 PM

Tom is right on the money!  Use 650° to 700° and don’t dally.  Pre tin both surfaces with a small amount paste (be quick on printed circuit boards) then less than 2 sec to attach the wire.
 
  
 
 
Mel
 
 
My Model Railroad   
 
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Posted by hon30critter on Sunday, September 22, 2019 8:43 PM

RR_Mel
Tom is right on the money! 

Ditto!!!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by BigDaddy on Sunday, September 22, 2019 8:52 PM

Live and learn, thanks Tom.

Henry

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Posted by irishRR on Sunday, September 22, 2019 11:33 PM

Thank you all for the insight. I will.be picking up my soldering paste in the morning and will keep you updated. Cheers!

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Posted by mobilman44 on Monday, September 23, 2019 5:32 AM

I've used a 30 watt Weller with very thin solder and hard wired 8 Stewart locos successfully with no damage.  As said above, the trick is to get the surfaces to be soldered clean, make sure the iron is up to a temp that readily melts the solder being used, and then to "get in and get out" fairly quickly.

If you are unsure of being able to do it right, experiment on pieces of wire, old decoders, etc., beforehand.

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by tstage on Monday, September 23, 2019 5:39 AM

Sorry, irishRR.  I erroneously used the term soldering "paste" in my initial post when I really meant to say soldering "flux".  (It's the same stuff found in rosin core flux solder - without the solder.)  Soldering paste is actually powered solder in a flux slurry.  It will work also but generally has a limited shelf-life and is not necessary for a good solder connection to your decoder board.

I purchased a 2 oz. jar of soldering flux at Radio Shack years back when they were still open and it should last me quite a long time.  I apply a very small amount of it to the soldering pad with a rounded toothpick after I've tinned it with solder.

Tom

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Posted by gmpullman on Monday, September 23, 2019 7:03 AM

irishRR
I will.be picking up my soldering paste in the morning and will keep you updated.

I might suggest you spend an hour or so with some junk boards until you become confident enough to tackle an expensive decoder. For some unknown reason I've saved many of my removed "light boards" from locomotive DCC installs. Something like these will make good practice fodder:

 DCC_PCBb by Edmund, on Flickr

Good Luck, Ed

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Posted by RR_Mel on Monday, September 23, 2019 7:14 AM

Actually Tom maybe not.
 
 
EDIT:
 
I’ve had this can for at least 20 years and it served me well.
 
 
When I was working on a Arduino NANO Expansion module I ended up with a slight resistance between two close spaced soldering pads.  I found out that the Alpha Paste had slight resistance, enough to interfere with the circuit.  After cleaning the board with alcohol everything worked OK.
 
After reading the back of the can I found out that the Alpha Paste isn’t totally corrosion free thus my reason for switching to Quickfix.   
 
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by gmpullman on Monday, September 23, 2019 7:48 AM

The Alpha Metals paste is acid based for non electrical use only.

Be careful with that stuff around PC boards! But you already figured that out Geeked

https://tinyurl.com/yy88cnnq

 More info here:

https://www.dccguy.com/?p=4886

Regards, Ed

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Posted by rrinker on Monday, September 23, 2019 10:21 AM

 I use this flux:

https://www.hnflux.com/page19.html

(just a satisfied customer, I don't have any stake in this company)

My Xytronics soldering station is the older one, without the digital readout (which in some ways I think is better - it's quicker to turn down to minimum if it will be a while before I need to solder again - but then the really fancy more expensive stations have a sensor in the holder so it automatically sets itself back when yu rest the handpiece). I don't think the digits 1-9 on the dial actually correspond to anything, but I usually set it to around 6 or 7 and get good result. I have a thermistor probe but I don't think it goes up tha thigh that I could calibrate it with. A friend recently bought a high end non-contact IR camera, if he ever brings it over I might be able to calibrate with that. But I found if I turn it up much higher, I just get more smoke and no better results (haven't melted any boards, but for years I soldered with traditional irons that just keep heating until they reach equilibrium, which usually puts them well over 900C.). Much lower and it's too low to quickly melt the solder - which in many cases is actually WORSE than having it too hot. It may take longer to melt the solder, but it's still hot enough to damage the board, so having to hold the iron on for a longer time is more likely to damage the board or a component than having it too hot and being able to get in and out quickly. This is also the effect that having a dirty tip causes - the heat transfers slowly, causing to you have to hold the heat on the joint for longer and longer to get the solder to melt and flow properly.

That flux is water soluable, and cleans up with water, but don't wash circuit boards in tap water. Deionized water is what you need, but I just use isopropyl alcohol wipes to clean up PCBs after soldering - although I don't always flux all the joints, I use a rosin core colder as well. I often use the alcohol wipes BEFORE soldering to clean off the area - especially if I've been handling the board. This helps remove any skin oils and the like that can interfere with soldering. Maybe overkill since using flux accomplishes much of the same.

                                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by RR_Mel on Monday, September 23, 2019 11:24 AM

I keep a bundle of cotton swabs handy along with a small bottle (2 oz paint bottle) with Alcohol to clean stuff up.  I like the Alcohol wipes but they don’t last very long around my hobby room, everyone in the house knows where they are.
 
I’ve had a MPJA 301A soldering station for about 20 years and I recently checked the calibration with a Laser thermometer, the specs on the thermometer say  -50°C to +400°C /-58°F to 752°F; Accuracy: ±1.5% or ±1.5.  
 
The Laser Thermometer is a cheapo off Amazon, it is pretty close to the reading on my soldering station.  Both are close enough for my needs.
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by zstripe on Monday, September 23, 2019 12:05 PM

I have been using Solder-It,  silver bearing solder paste for about 8yrs. now and have absolutely no complaints with it. The paste has the solder and flux mixed together in the paste. Low melting point of 430F degree melting point. Turns to a bright silver when heated and is 5-times stronger than any 60-40, 60-37 solder:

https://www.walmart.com/ip/Solder-It-SP-7-Silver-Bearing-Solder-Paste-7-1-Gram-Syringe/48345692

In the photo is a Walthers car with lighting kit and I soldered two Kadee coupler knuckle bronze springs to the lighting LED Pc board using the solder paste. There is no need to hold the spring. Just stick it in the paste and touch the iron to the joint and you are done. I like it mainly because, not only is it stronger, but You have one hand free........no need to hold solder to the joint. Works great for Me in all delicate apps.

The two springs connect with the two tabs along the end inside of car:

Some people may think it is too pricey.....but I personally don't care about costs..........it works, that's all I care about......... I'm just 78....what do I know? Been playing with trains since 1950........

Take Care! Big Smile

Frank

BTW: I use a Mudder variable temp iron from 0 to 60 watts.

 

 

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Posted by richg1998 on Monday, September 23, 2019 12:50 PM

I have not soldered in about eight years with my WLC100 station but never paid attention to temp. There is not a temp indicator. I used the fine tip point and practiced on scap PC board materiaal first and #30 wire. I think I set the knob at about half way.

I used Cardas Quad Eutecrtic solder. Goes from liquid to solid very fast.

I have used solder paste on SMT stuff in a toaster oven. Works nice.

Actually been soldering for many years.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by irishRR on Monday, September 23, 2019 5:55 PM

Hello All! I figured as the OP for this thread, I should give an update. I have successfully installed a TCS CN-GP two part decoder into an older 1993 N scale Atlas/Kato GP-30. This was my first time doing a non drop in decoder, and I was nervous, but managed to pull it off. Had some difficulty maintaining the tinning on my new soldering tip, and had to re-tin a few times... but got it to work. I have to clean the metal wheels to improve on the electrical pick up and the loco runs a little louder than my newer locos, but that is to be expected. over all, I am pleased with the results of my first wired in decoder. Thank you all for your help. Cheers! Bow

 20190923_173422 by John Collins, on Flickr

 20190923_173307 by John Collins, on Flickr

-John Collins

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