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Usually I just leave stock motors alone and any solder on the cans gets to stays there and add character.

But I recently acquired a Kyosho Le Mans 240S where the previous owner soldered several caps directly to the can, in multiple places. The caps were in rough shape and I removed them. Now I'd like to remove the remaining solder as cleanly as possible. I'm considering again trying to wick it into some copper braid with flux and my hand-held iron on max heat, but this didn't work so well for me last time... maybe I just wasn't patient enough -- it's hard to get enough heat into the can. I also have a larger, gun-type iron, and may try that instead. 2 of the 3 solder spots are near the label, which I'd like to save, so wondering if I may need a different technique...?

In looking around I recalled juicedcoupe used a mini torch and brass brush on the brush hoods here: https://www.rc10talk.com/viewtopic.php?p=536561#p536561

Any other suggestions or recommendations?

Thanks!

I cut off what I can with mini cutters, then use a flapper wheel on a Dremel. On silver canned motors, I'll polish it a little with a Dremel.

You also can get most of it off with a solder sucker.

Pick yourself up a solder wick, works wonders.

Also make sure your iron is up to the task, a 25w pencil tip iron won't cut it. Use an 80w flat tip, basically the same as what you'd use to solder batteries and 12g connectors would be fine.

If you want to save the label, I would honestly just shave it off with a fresh xacto blade, kind of like whittling a stick. Then follow up with a Dremel with a wire wheel or buffer/sanding drum. If you use the drum do it very carefully so you don't dig into the can.

RC10th wrote: ↑Sat Nov 30, 2024 7:39 pm Pick yourself up a solder wick, works wonders.

Also make sure your iron is up to the task, a 25w pencil tip iron won't cut it. Use an 80w flat tip, basically the same as what you'd use to solder batteries and 12g connectors would be fine.

I'll see what happens with my stronger iron. I'm wondering if my existing wick has oxidized too much for the flux to help. It seemed to work when new, but either it (or me) is not the same now. Will give another try regardless.

juicedcoupe wrote: ↑Sat Nov 30, 2024 6:55 pm I cut off what I can with mini cutters, then use a flapper wheel on a Dremel. On silver canned motors, I'll polish it a little with a Dremel.

jwscab wrote: ↑Sat Nov 30, 2024 7:43 pm If you want to save the label, I would honestly just shave it off with a fresh xacto blade, kind of like whittling a stick. Then follow up with a Dremel with a wire wheel or buffer/sanding drum. If you use the drum do it very carefully so you don't dig into the can.

I trimmed it already a little with cutters. May try an exacto to get some more off. Unfortunately don't (yet) have a Dremel... What does the suface look like afterwards? Will I be able to blend it with the surrounding surface? Ideally I'd like to keep the can as close to the original finish as I can. I don't have much experience with polishing.

mikea96 wrote: ↑Sat Nov 30, 2024 6:59 pm You also can get most of it off with a solder sucker.

My sucker must not be very good or I just don't know how to use it properly (possibly a theme here lol). May give it another try!

I use a soldering iron and xacto knife. Soldering iron tip is clean but has no excess solder on it. Reheat the solder and rotate iron tip to collect excess solder onto the tip. Clean off tip and repeat.
Try not to get the can hot. The solder doesn't adhere very well to a cold can. Use the xacto blade to pry up the edges of the solder and to cut/shave through the soft solder. Be careful not to cut yourself with a blade that has been used for cutting lead solder.

I would use the copper braid but I don't have any on hand. I miss Radio Shack.

I hate to say it but more than likely the can was probably scuffed through the coating to get the solder to stick properly in the first place. I do believe your going to go through a bunch of trouble just to find the finish is gone anyway.

I find the wick works best when it's slightly tinned, don't cut the copper braid off at clean copper but where it starts to discolor from previous wicking. Melt the solder on the can as you would when you tin the joint to make a connection, then press the braid into the solder with the iron. Keep in mind that a little solder goes a long way in the wick so removing as much solder as you can beforehand is helpful.

I wouldn't worry too much about damaging the label as the whole process only takes about as much time as it did to make the initial joint, so if the label didn't melt in the first place why would it now? If you think things are getting too hot take a break and let things cool.

MarkyDents brings up a good point about the can being scratched to get the solder to stick, if this is the case the best solution would likely be to get some new capacitors and re-do them so they look like a professional job, although that might be harder done then said if it's soldered in multiple locations though.

Some of my motors now have intentionally large (but clean) solder joints on the can, to cover previous jobs.

Everyone ran capacitors BITD. So worst case if you can't get it cleaned and polished to your satisfaction, just do a nice clean re-installation. It won't detract from the look or authenticity of the motor. If you run it with a modern radio, the caps won't cause any issues. They just aren't needed like they were with AM radios.