R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 09-28-2005, 05:00 AM   #1
Tech Master
 
Join Date: May 2004
Location: New Zealand
Posts: 1,204
Quick question.....solder joints.....

I've been doing a lot of soldering lately (first for a long time) and I'm not sure if this example is correct.

Take for example soldering the Esc wire onto the motor terminal.

I'm using a 60 watt iron with a chisel tip and a 60/40 (I think) solder (with flux already included).

So I put a little solder on the terminal and it looks all nice and shiny and I've tinned the end of the motor lead and it looked all nice and shiny but the instant I took away the heat it "dulled over" is the best way I can think to describe it.

Then when I put the tinned wire onto the terminal and applied heat the two parts joined almost instantly and looked all shiny as above but again once the heat was removed it "dulled over".

Try as I might I can't pull them apart (so it seems strong) and the "dulled over" part only requires a very light pass over with a blade (for example) and it's shiny again and stays that way.

Does any of this sound bad (or not) and either way what's the reason for the dull?

Thanks in advance.

Last edited by Mabuchi540; 09-28-2005 at 05:10 AM.
Mabuchi540 is offline   Reply With Quote
Old 09-28-2005, 05:08 AM   #2
Tech Champion
 
geeunit1014's Avatar
 
Join Date: Sep 2005
Location: The dirty burnie
Posts: 5,505
Trader Rating: 12 (100%+)
Default

Normaly (for me anyway) the solder goes not shiny when hardened, but who cares if it looks prettty or not, it matters if it stays attached
__________________
Mike Gee

Awesomatix USA/Pyscho Cells Racing/Tekin/Sweep Racing/RSD/180 Raceway/Johns Mobile Raceway/TQ Wire/Avid/Sanwa
geeunit1014 is offline   Reply With Quote
Old 09-28-2005, 05:11 AM   #3
Tech Master
 
Join Date: May 2004
Location: New Zealand
Posts: 1,204
Thumbs up Indeed....

Quote:
Originally Posted by geeunit1014
Normaly (for me anyway) the solder goes not shiny when hardened, but who cares if it looks prettty or not, it matters if it stays attached
attached is good, staying attached is better, staying attached AND pretty is best.

I'd kinda like to know the "why" of the "dulled over" though lol.
Mabuchi540 is offline   Reply With Quote
Old 09-28-2005, 06:20 AM   #4
Tech Champion
 
Join Date: Oct 2004
Location: Long Island, NY
Posts: 7,211
Trader Rating: 2 (100%+)
Default

What you describe is normal. When solder cools it has that dull finish you describe. A 60 watt iron is plenty. 60/40 rosin core solder is perfect for what we do.

60/40 refers to the ratio of tin to lead. So 60/40 solder is 60% tin and 40% lead. The rosin core flux is designed to melt before the solder does to clean the contact area.

And never use acid core solder on anything electrical!
jiml is offline   Reply With Quote
Old 09-28-2005, 06:22 AM   #5
Tech Champion
 
Join Date: Oct 2004
Location: Long Island, NY
Posts: 7,211
Trader Rating: 2 (100%+)
Default

One more thing, never blow on the solder to cool it faster. That makes the joint brittle.
jiml is offline   Reply With Quote
Old 09-28-2005, 07:03 AM   #6
Tech Master
 
Join Date: May 2004
Location: New Zealand
Posts: 1,204
Thumbs up Thanks dude.....

Quote:
Originally Posted by jiml
One more thing, never blow on the solder to cool it faster. That makes the joint brittle.
nice to know that it's a normal thing. I thought (read hoped lol) it might be so I'm not letting go of either part until it dulls as I assume now that means it's set so to speak.

Thanks for the info about the acid solder/don't blow on it to cool, I didn't know that either.
Mabuchi540 is offline   Reply With Quote
Old 09-28-2005, 09:40 AM   #7
Tech Addict
 
Join Date: Feb 2004
Location: Iceland
Posts: 588
Default

You don't say if the solder is just slightly dull or if it's dark gray. Just slightly dull is ok, dark gray is sign of all the rosin having evaporated from the solder.
If you let the rosin evaporate from the solder by heating it too long, or too much, the result will be dull finish and weak joint that has high resistance and will heat up and reduce power. To get good shiny finish you need to remove the solder used, replace it with fresh one and use soldering station with temperature control. Don't solder much above 300c for detail soldering, the rosin will evaporate too quickly.
60/40 rosin core solder is the best choice for beginners and/or people who don't solder regularily and/or don't have good soldering epuipment.
andsetinn is offline   Reply With Quote
Old 09-28-2005, 03:24 PM   #8
Tech Master
 
Join Date: May 2004
Location: New Zealand
Posts: 1,204
Post Oh it's.....

Quote:
Originally Posted by andsetinn
You don't say if the solder is just slightly dull or if it's dark gray. Just slightly dull is ok, dark gray is sign of all the rosin having evaporated from the solder.
If you let the rosin evaporate from the solder by heating it too long, or too much, the result will be dull finish and weak joint that has high resistance and will heat up and reduce power. To get good shiny finish you need to remove the solder used, replace it with fresh one and use soldering station with temperature control. Don't solder much above 300c for detail soldering, the rosin will evaporate too quickly.
60/40 rosin core solder is the best choice for beginners and/or people who don't solder regularily and/or don't have good soldering epuipment.
Slightly dull/light grey (well I think so anyway lol) in that you can still see some relection in it if that makes sense.

I wish I had a solder station with temp control, as it is it's a $12 NZ iron I'm using.
Mabuchi540 is offline   Reply With Quote
Old 09-29-2005, 03:37 AM   #9
Tech Master
 
Team Duratrax's Avatar
 
Join Date: Aug 2004
Location: NSW, Albury/Wodonga
Posts: 1,674
Send a message via MSN to Team Duratrax
Default

The more solder you apply the more dull it will be when dry. Use only what you need, don't go overboard with the solder. You will only gain more resistance through the solder.

I haven't heard of anyone using chisel tips to solder wires together. They are mainly used when you start assembling your own cells.

Sean
Team Duratrax is offline   Reply With Quote
Old 09-29-2005, 10:42 PM   #10
Tech Master
 
koabich's Avatar
 
Join Date: Oct 2003
Location: Detroit Area
Posts: 1,359
Send a message via Yahoo to koabich
Default

Guys, the brighter the solder joint is, the stronger and more conductive that joint is.
Check out any qualily solder job from a manufacture. The joints that are visable on an LRP speed controler (at least the Q2's) are mirror finish.
SMC has made several packs for me and their hand solder joints are also mirror finish.

I am sure alot of the finished color has to do with the quality of solder and the temperature/quality of the soldering iron. Dull color joints normally mean the joint is a "cold" joint or that the iron was not hot enough when making the joint.
koabich is offline   Reply With Quote
Old 09-30-2005, 09:59 AM   #11
Tech Adept
 
graphiteman's Avatar
 
Join Date: Dec 2004
Location: Orange County, CA
Posts: 135
Trader Rating: 3 (100%+)
Default Solder

My suggestion is in the solder itself. Dont just buy the crap you see in the Radio Shack, get the Deans solder (or equivalent) and pay more for quality solder. If you try the Deans brand, you will see a difference. Just my .02
graphiteman is offline   Reply With Quote
Old 09-30-2005, 01:39 PM   #12
Tech Addict
 
fraz's Avatar
 
Join Date: Mar 2002
Location: Santa Cruz, CA
Posts: 653
Send a message via AIM to fraz
Default

What you describe is the early stages of a "cold" solder joint. To avoid cold solder joints make sure you do the following. After applying solder or heating the two items being soldered, keep the iron tip on both points until you see the solder flow completely through the joint. Not very long but most people in r/c I see removing the heat as soon as it melts and that is wrong. The other biggie is to keep the pieces being soldered absolutely still. If you move a curing solder joint it will cool prematurely and be a weak brittle "cold" solder joint. Follow these rules and your contacts should be awesome.
fraz is offline   Reply With Quote
Old 10-01-2005, 11:31 PM   #13
Tech Fanatic
 
calstarjig90j's Avatar
 
Join Date: Apr 2004
Location: San Diego
Posts: 823
Trader Rating: 2 (100%+)
Default

A lot of good points out here. I always remove old solder re-tin motor tabs and motor wire, put the two together and heat with a little solder on the iron. You want to see the entire joint melted not just a partial melt. Blam shiny and just the right amount. Takes some practice but the amount of heat you place, the positioning of your iron tip on that joint and the amount of time you leave that solder iron on there has a lot to do with it also.
calstarjig90j is offline   Reply With Quote
Old 10-02-2005, 03:56 AM   #14
Tech Master
 
Team Duratrax's Avatar
 
Join Date: Aug 2004
Location: NSW, Albury/Wodonga
Posts: 1,674
Send a message via MSN to Team Duratrax
Default

TIP: If you are unhappy with your solder joints you can always use a spare brush shunt to soak up the solder so you can re-do the joint.

Sean
Team Duratrax is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Solder / Solder Stand - Available Online? RC12 Electric On-Road 7 05-01-2008 10:20 AM
Solder question... MSCAVA Electric Off-Road 3 08-18-2007 05:50 PM
Quick TCS question Turbo Joe Electric On-Road 6 05-31-2004 01:26 AM
a quick question benraldo the ho Electric On-Road 7 03-29-2004 11:46 AM
Solder Question TRF-Powered Electric On-Road 15 03-28-2002 11:25 AM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 08:49 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net