What solder to use?

Hey guys its me again, I almost have my AG builds done and ready for more testing when it just occurred to me that I might have used the wrong solder. The drones are 6s and 12s for the bigger one.
I have been using Harris lead free Rosin Core 97/3. Will this be good enough or should I clip the connections and start over with something more robust like silver solder 60/40 lead free? The smaller JMRRC X1000 has been tested on the ground, voltage reads right, none of the lines are getting hot and no explodie. But that’s not under load so just concerned. About to get my Remote PIC and don’t want to blow things up, any suggestions?

Is that plumbing solder? I can’t find any solder type from major brands like Kester or MG Chemicals that use 97Sn/3Cu. If it is plumbing solder, best not to use it for electronics if you have a choice.

By 60/40 I assume you mean 60Sn/40Pb? (If one of those was silver that would be really expensive!) Avoid this and instead use a eutectic solder like 63/37. They are easier to use as they have no plastic region before the actual melt point.

If you are new to soldering stick with a leaded solder as they are generally easier to work with and melt at lower temps. This is nice when soldering large connectors if your soldering iron isn’t the greatest.

As long as you think you don’t have cold solder joints you should be ok… But if is plumbing solder you should likely redo it for long term use. The flux in plumbing solder is usually more acidic than should be used for this application.

Here is a decent type to start with as “No Clean” solders can be harder to work with,

Here is a good guide that shows different join types,

Thanks Josh, just ordered some. I’m gonna clip and de solder the connectors I made and start over. XT90’s, AS150’s and 4mm bullet plugs

Oh and I didn’t add it here. Eventually, you will likely want some desoldering braid and a flux pen.

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You will find 63/37 to be easier to work with but 60/40 is fine. Lead free solder should only be used if RoHS requires it or you are just paranoid about lead.Then you have no choice but that’s rarely the case at the hobby level.

Leaded solder is definitely the best if you are allowed to use it.

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Is there a difference in strength with the lead free? They will have up to 80 amps running through the connectors. I should have payed attention, the first stick i used on the first machine was 60/40. when I ran out i just grabbed what ever off the shelf thinking the only diff was rosin core or not, you know woth the flux.

If you mean current carrying capability? Then no for your use either is fine. The highest resistance item in the loop isn’t going to be the solder between the wire and the connector’s solder cup.

If you mean mechanically there are differences, but those don’t matter for you.

Like Dave said 60/40 is fine if that is what you used. The important thing with 60/40 is to not move the pieces being soldered while it is cooling and to be sure you have actually melted the soldered.

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As Josh says. Also, it’s more difficult for the hobbyist to detect a cold joint with Lead-free solder. Leaded solder makes a nice shiny ball when corrent and often dull when cold. Lead-free is always dull :slight_smile:

So the 97/3 I used is still fine for the connectors? XT90, As150? I just de soldered the As150’s I got some 60/40 from amazon yesterday, but its chinese. Didn’t get to my messages before I ordered the 63/37 you suggested. I re-tinned the leads with the 60/40 as the 63/37 won’t be here till tonight, and noticed that it flowed better, almost like water, while the 97/3 was really, really hard to keep in a liquid state and dunk the wires. Ever heard of Anotek? that’s the brand of 60/40 I got. not much in the description. This may sound stupid but what does the Sn/Pb mean?

My personal recommendation is to redo anything you used with what I think is plumbing solder.

That 60/40 solder is probably fine I wouldn’t worry so much if you think you got a good joint.

Not a stupid question!
60Sn/40Pb = 60% Tin / 40% Lead

Thank you very much Josh, I thought you might be referring to the periodic table, but I’m new, and though it might stand for somethin else like lingo. I have a lot of soldering to redo, but hey practice makes perfect. Judging by how the 60/40 flows it should be easier to use the 63/37 when it arrives tonight. Thanks again to everyone in the community that responded :slight_smile:

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Hey josh thanks again, that [4880-4888 - Sn63/Pb37 RA Solder Wire is awesome, flows like water much easier and solid connection almost done re-soldering everything. Thanks everybody

Glad to hear it! Good luck on your soldering journey! And do look up getting a flux pen and some desoldering braid for the future.

The flux pen is useful for those times where you need to add solder to the tip first and bring it to the item to be soldered. (Useful for the time/places where three hands are required to feed solder, hold iron, and hold the piece to be soldered.) You must always have flux.