R/C Tech Forums - How to solder correctly (a not so brief lesson)

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ok, my pops gave me a small roll of some desolder...it looks like a roll of braided wire and not real sure of the proper way to use it to remove solder from connections, can someone help?

Ordered a new truck and it will be here tues and i want to clean up the connections on the esc and remove as much solder as i can so i can have a fairly clean slate to work with

Quote:

Originally Posted by TCCustoms (Post 11879552)

ok, my pops gave me a small roll of some desolder...it looks like a roll of braided wire and not real sure of the proper way to use it to remove solder from connections, can someone help?

It works like a solder sponge.

Put some fresh flux on the braid, and then heat up the braid and solder together, and the braid soaks up the melted solder.

Quote:

Originally Posted by marine6680 (Post 11881580)

It works like a solder sponge.

Put some fresh flux on the braid, and then heat up the braid and solder together, and the braid soaks up the melted solder.

KOOL, never used anything to deselder and not usually one to take stuff apart but i sold my truck recently(kept the electrics) and want it nice and cleaned up so the solder job will go easy and my dad gave me that so i wanted to make sure i use it properly

Johnny-

This rework station is built for lighter temp small gauge wire and PC board components. I don't think it would solder motor wires or battery connectors onto 10,12,14 gauge wire very well. Probably would struggle to put out enough heat to properly solder most RC type connections.

It does have a nice heat gun for heat shrink tubing, though.

Quote:

Originally Posted by wrongchannel (Post 11883222)

But it's a 60w unit. The pencil iron I have now is only 45w and I can solder 12ga wire with it. I just wanted to step up to a solder station. The heat gun is a cool bonus.

Not familiar with the brand... if its ceramic heating or coil... but 60w plus a large tip will be fine if it is quality enough to hold temps well.

Make sure you can get replacement tips for it and in the size you need.

The heat gun will work great for heat shrink.

I have a Hakko, 935 I believe ( it's packed away in my RC stuff at the moment ).
I purchased it, I'd hafta say at least two years ago. It was an Ebay deal, and came with tips that ( I'm betting ) were not Hakko tips. However, up until very recently, it has been flawless. Basically, the solder ( Kester 63/37 ) just balls up, sputters a bit if I move too much flow too quickly, and simply falls off the tips. Just yesterday, I even purchased a genuine Hakko bagged tip from my LHS...same thing. I can tell it does in fact still transfer heat through the wiring, and I can effectively "force" it to break a connection by adding solder as it will melt once it is on the wire...just not on the tip. I've also tried playing with moving the heat control knob, thinking maybe it possibly was out of calibration somehow and too hot. No change. As I'm typing this, the one thing just came to my mind that I have yet to try is different solder. The roll I have is probably no older than a yr. Is it possible that the solder has been contaminated somehow or simply gone bad? Any clues, hints, advice aside from testing another roll which I'll do tomorrow? Is the iron done, time for a new one?

Thank You for your time and thoughts. :)

If I am understanding you correctly... the solder will melt if you touch it to the iron tip but will not stick, it just balls up and rolls off.

Solder balling up and not sticking to the tip... I would first blame it on a dirty tip, but if you used a brand new tip then that is probably not the issue.

Solder balls up when melted if it can not get a good bond and wet the metal it is touching. This is almost always caused by a contaminate of some kind.

Make extra sure the new tip is completely clean, if it is an old tip, it could have a little oxidation on it. Maybe try some tip tinner. It comes in a little metal container and you dip your tip in it to clean and tin it. Radio Shack carries it usually. Make sure you get lead type.

If that is not the case, the flux core in the solder could have gone bad, try using fresh flux.

Solder can get old and oxidize, but usually lasts a few years.

If you have a IR thermometer, measure the temp of the tip after its fully heated. If it is very far off what the temperature setting knob is set to, it may be fixable if the unit has a calibration screw. If it is too bad, you may not be able to adjust it enough. If the tip can reach 650* it should be good to solder with, but if the iron element is getting flaky, you may need to source a new element or iron handle.

Well, I've tried numerous ideas, including my solder on a friend's iron, which worked properly. Nothing I've tried seems to be working with my iron. So, I think I'm gonna try my luck with
http://www.ebay.com/itm/Soldering-Ir...item589c1ef5fe

Beats shellin out $80+ for a totally new station. I wasn't able to confirm temp with a gun, but it does change dependent on where I move the control knob, so I think I'll be good. :)

So long as the problem is in the handle and not the station it should help.

It is usually the handle that is the problem.

To marine6680,

Thanks so much for posting all of your helpful information. My soldering skills have improved 10 fold after reading your posts. I no longer have ANY soldering issues or bad connections. I'm still learning but with all of the great info you've posted I now solder with much more confidence. Thanks again.

Quote:

Originally Posted by timannnn6 (Post 11991823)

Thanks and you're welcome.

Quote:

Originally Posted by bluechucky (Post 6748366)

marine, could you please elaborate on the "bird-caging" term? Never heard of it.

Quote:

Originally Posted by marine6680 (Post 6749309)

That example can never happen, (on new components) the only time I see something like that is when the component is VERY dirty, and the flux can not do its job. In those cases, the solder doesn't even begin to stick to the components and the wire would not make a connection and when you clean the sticky flux away it comes loose. Trust me, you WILL know if the wire is not connected. To get so much corrosion that you have that problem, you would need to soak the connector is salt water for months.

Flux can not mix with metal, there will never be a mixture of flux and solder. Flux will remove the oxides from the metal surface and leave fresh clean metal for the solder to stick to. The solder creates a molecular bond with the metal, that can not be separated again. When solder gets put on that shiny gold connector, it will forever remain silver looking, the solder will remain on there unless eroded away with something like sand paper. If you can see the solder flowing and sticking to the component, then you are fine. There is a reason why solders come with flux cores, flux is good.

Simply put: Flux will do its job and then get out of the way.

When the solder starts to stick to the component the flux will not get in the way. The molecular bond is much much stronger than the physical stickiness of the flux.

Bird-caging is when the individual wire strands of multi stranded wire (like that used in RC) separates from each other.

Take a piece of wire and strip an inch of insulation off the end, then twist the wire end the opposite way the strands are twisted together, they will start to separate and leave gaps between them, like the bars of a bird cage. It disturbs the natural "lay" of the wires and requires more solder to fill the gaps, this is a less efficient connection.

While solder is less conductive than copper, a solder connection (which is molecular) is far less restrictive than a mechanical type of connection. (crimp type like terminal lugs and splices or contact type like in battery/bullet connectors) Besides, the short distances we need the power to flow in an RC car means the difference in conductivity of different metals is not so important as it is in other areas, like power grids and precision equipment.

Can you fix wire that has "bird caging" without snipping off the end of that wire?

Thanks.

Quote:

Originally Posted by padjr1 (Post 12116379)

Can you fix wire that has "bird caging" without snipping off the end of that wire?

Thanks.

Yeah, just try gently twisting the wire strands back to its original position. Just don't twist too tightly, just enough, you want solder to flow between the strands easily.

Not as quite good as wire that was never deformed or birdcaged, but still good.