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Solder type at contact points?


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My first build is still in the postponed stages although looking at the board again I was wondering what the make up of the solder would be on the board at the contact points?
I'm just a fans of the silver bearing solder is the reason I ask. I've been lead to believe that silver bearing solder can lend up to 15% more conductivity than other compositions of solders.  

Yeah I could over engineer a tooth pick. xD


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Interesting question, but not sure it would make any meaningful difference for surface mount in this application, but it wouldn't hurt either, belt and braces engineering.  You used to be able to get audiophile silver solders, probably still can I have not had to buy any for a long time, but IMO always have good mechanical contact for your joints and treat the solder more as slightly conductive glue.

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This has been my flavor for a while now although the price has probably gone up a fair margin. Anything with a higher silver content would have me fearing overheating components. Yeah there'd likely be little difference in conductivity the way I try to solder anyway.  I try and use alligator or some form of pressurizing clips to hold wires in place while soldering to get as substantial a mechanical bond as possible while soldering, splaying wires if possible..... 
[IMG_20150125_111238_zpsw73p2iii] 

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Haven't seen Tandy (what Radio Shack called themselves in the UK) over here for years, I will keep an eye out for the silver bearing solder though.  I like alu heat shunts holding the wire and holding these in the alligator clips, stops solder stiffening the wire by capillary action.

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True, the volume resistivity of silver solder over standard eutectic lead bearing solder ranges from 15% to 25% less resistance for a given volume depending on the exact alloys used, etc. But if you really want to go there, you also have to consider percentage of what. Volume resistivity of typical silver solder is around 1.03E-5 ohm-cm. Thats about ten millions of an ohm in a one cm cube or 100 millionths of an ohm in a one mm cube. Even if the joint was only 1 mm square of solid solder, the difference between the types is like 15 nano-ohms. I just can't see it making much difference when we are basically struggling to measure ones and tens of milli-ohms. It can't hurt to use a silver bearing solder but plain solder is fine . . . and a lot easier to work with lol.

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Someone, I think it was Vaping Bad, discovered the trick.  Use a VT 510 and drill the hole in the brass cap at the bottom large enough for the wire to slide through.  Strip enough insulation so the wire can move up and down in the cap and there's enough room to solder on the pin.  After soldering on the little pin and reassembly, use some heat shrink to cover any exposed wire.

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I've used 12 stranded and fine stranded (and the fine stranded is a challenge). Your idea works perfect for that too. It takes a bit of care and a hot iron (I use 150 watt iron for this) but it definitely works. There is no room for the insulation after drilling, just the wire. A bit of heat shrink over the exposed wire after soldering and assembly finishes the job.

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Podunk Steam said:

So you heat synced the wire in order to not over heat the spring?

The spring rests on the collar that slides down the wire about 7 mm or so. Thermal contact between spring and wire is minimal. Beyond that, annealing temp of even high carbon steel is around 1,400 F. Solder melts under 400 F. Unless you solder with a torch, spring will be just fine.
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[IMG_20150702_115804_zpsdzh6hz9k] 

Although I don't remember the connector manufacturer this is 14 gauge high strand count silicone coated wire. A bit of a trick to get this far with it. I pulled the insulation back on the wire, cut the wire, slid the insulation over the end of the wire, cut the insulation at an angle, fed the insulation through the cup and than the spring.
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Podunk Steam said:

So you're saying the spring will fit over the insulation of a 12 gauge wire?

Irrelevant because the collar won't. If you want to go with 12, drill the collar to fit 12 wire. Strip enough insulation so the collar and spring will slide down far enough to give clearance to solder the pin. Solder with a high watt soldering iron (I use 150 watt). Assemble the pin, spring and collar. Heat shrink over the bit of exposed wire under the collar. Done. Some heat will transfer from wire to collar to spring. It is not enough to anneal the spring. Cheers.
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Yeah, you're talking about soak temps and I think you're still low. A full soak is heat the metal through and through, not touch it at a temp for a few seconds with heat transfer through multiple parts and mediums. You can't get a full soak on that spring anywhere near to even just 700F witth a soldering iron, even applied directly to it. The iron isn't hot enough, the heat transfer is not efficient enough and the amount of time is not long enough. Also, if the spring used were adversely affected at 250 F, I would be concerned about heat transfer from a 450F coil a few millimeters from the pin as well as up to 200 watts through the wire and pin transferring the heat to the spring just as much as 400F or 450F soldering iron at the pin and end of the wire. Etc. I guess I just don't understand your obvious hostility to the concept. If it's that big a deal to you, apply heat sinks to the spring and be happy? I've done it the exact way I describe with no issues so I feel comfortable suggesting the method. I learned the idea from another knowledgable person here. If it doesn't work for you or you don't like it, don't use it. Cheers.

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Cheap spring steel you might as well sign off at 250F.

Springs this small don't have much metal to them so they will heat readily although the carbon content in quality springs is likely higher than cheap spring steel. 

I have seen springs that have lost temper being heated with soldering irons in this same manner and I'm not the first. Granted these I've seen were cheap Chinese springs, it does, has and likely will happen to someone again.

I'm sorry you're mistaken, I'm not the slightest bit hostile or there'd be no question as to my state. I honestly don't consider it good practice to heat springs in the process of soldering. I own it, my opinion, you're welcome to yours as I am mine. Nothing to be hostile about here. 

Salute
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