Is this really LMP silver solder?

[eccerr0r]

I bought a roll of solder, I think just under 0.5lb (haven't measured) for $4 USD. I initially noticed it said "L.M.P. Silver Alloy" and perhaps this really is silver solder (62/36/2)...but is it?

I don't know how accurate my solder iron is but that will be my first check...though I wonder if the resolution would be high enough, or if I have actual 63/37 to compare against.

Any other qualitative tests I could do?

The spool is an old wooden spool. "Multicore Ersin Five Core" and "B62 Flux" (???) but it could have been a respool (though doesn't look like it.) Cutting off a piece and seeing if it has 5 cores would be something I should check too.

Did I get ripped off?

[stj]

Re: Is this really LMP silver solder?

at $4 for 500g, if it melts you got a deal!

i just spent 26€ + tax for a 500g roll of solder last week!!
mine is a bit special with added nickel & germanium - but it's still much cheaper than silver.

[eccerr0r]

Re: Is this really LMP silver solder?

Oh I wish it was actually 500g, but unfortunately I only got I'd say around 250g (I just measured the spool+solder at 12oz, couldn't measure when I bought it. I just hope the wooden spool doesn't weigh 11oz )

FSCK my solder iron bottoms out at 200°C which would melt both 63/37 at 183°C and 62/36/2 at 179°C ... need to figure out another way of testing... At least the cut test indicates it is indeed "Multicore" (I see 5 cores!) just no proof it's got that silver in it...

[eccerr0r]

Re: Is this really LMP silver solder?

pictures of lead...

[stj]

Re: Is this really LMP silver solder?

nice photo!

it may have silver in it.
i noticed with my silver solder that it has a different look, like a slightly green finish in the light.

[eccerr0r]

Re: Is this really LMP silver solder?

Weird... silver directly doesn't have any weird oxidation states that would have something to do with green, though that doesn't rule out any complexes.

Oh well, at least I did learn something, was thinking the silver was to protect the silver plating of certain surfaces but that doesn't make sense to me. The slightly lower melt point does, like those terminal pads on old Tektronix equipment. I was wondering why they required silver solder, but if those things were easily damaged by soldering irons, it makes sense.

[stj]

Re: Is this really LMP silver solder?

silver lowers the melting point, but to solder to silver plate such as peizo resonators i think you need about 5% silver.

[eccerr0r]

Re: Is this really LMP silver solder?

That makes sense, was wondering about tektronix barrier strips they use, I don't see why they would have silvered every barrier contact -- or maybe they did... hmm...

[Sparkey55]

Re: Is this really LMP silver solder?

Weird... silver directly doesn't have any weird oxidation states that would have something to do with green, though that doesn't rule out any complexes.

Oh well, at least I did learn something, was thinking the silver was to protect the silver plating of certain surfaces but that doesn't make sense to me. The slightly lower melt point does, like those terminal pads on old Tektronix equipment. I was wondering why they required silver solder, but if those things were easily damaged by soldering irons, it makes sense.

The reason why you would use solder with a silver content on silver plated contacts is prevent leaching of the silver plating into the solder mix.

[stj]

Re: Is this really LMP silver solder?

i think the reason for the silver to begin with is that it bonds to ceramic.

[redwire]

Re: Is this really LMP silver solder?

I've used it to solder to stainless steel

[eccerr0r]

Re: Is this really LMP silver solder?

i think the reason for the silver to begin with is that it bonds to ceramic.

This is the piece of information that was not clear, at least for the terminal bridges on Tek gear. If the terminal bridges are made out of silver, then yeah, definitely use silver solder.

It makes sense for piezoelectric elements, as the metal plating indeed is silver and tarnishes over time, not to mention the heat can damage the crystal...so that I understand.

I also wonder why anyone would actually plate a metal contact with silver -- only if there was no contact to begin with (plated through hole, etc.) -- since silver corrodes as much as copper or steel, might well use gold... or even plain old tin.

[Sparkey55]

Re: Is this really LMP silver solder?

This is the piece of information that was not clear, at least for the terminal bridges on Tek gear. If the terminal bridges are made out of silver, then yeah, definitely use silver solder.

It makes sense for piezoelectric elements, as the metal plating indeed is silver and tarnishes over time, not to mention the heat can damage the crystal...so that I understand.

I also wonder why anyone would actually plate a metal contact with silver -- only if there was no contact to begin with (plated through hole, etc.) -- since silver corrodes as much as copper or steel, might well use gold... or even plain old tin.

Silver conducts electricity better than any of the metals you mentioned.
Silver Oxide is conductive to electricity.

[eccerr0r]

Re: Is this really LMP silver solder?

Silver Oxide is conductive to electricity.

1. corrosion causes surface defects which will reduce contact area for removable contacts, increasing resistance. And usually it would be sulfide of silver that's the problem, not the oxide which does not form as readily.
2. just like Amdahl's law, you're not making the whole circuit out of silver, and the miniscule amount of silver in a small plated contact will not make much of a difference. While plating an entire surface like piezoelectric crystal, or capacitor terminals make a difference, small contacts as a portion of full circuit length like barrier strips does not.

However if it just was Tek finding silver the easiest thing to stick the barrier strips, then that's definitely the ultimate reason to use silver.

[Sparkey55]

Re: Is this really LMP silver solder?

Trying to get anything across to you is fruitless. I give up. Go live in your fantasy world. Anyone that has more age on you is wasted. Fuck you and the horse you road in on.

[eccerr0r]

Re: Is this really LMP silver solder?

I don't see what you're trying to do other than making yourself feel all smartass (including your last comment). I very well know the issues on hand and don't need anyone with "more age" to repeat something I already know. The intent of the thread is not the advantages of silver - it's to identify it. If you just wanted to make a statement about facts, don't imply that someone's wrong by quoting them, especially when it's off topic. Perhaps just some posting etiquette will get you a nicer response.

You can go do the same to yourself if you feel you need to resort to that kind of language when you write something that shows superiority and then get shown the fallacies. Basically isn't that what you're doing in the first place?

[stj]

Re: Is this really LMP silver solder?

it's about bonding.
some metals bond to things better than others.

example, you cant chrome-plate steel.
they are too far apart on the periodic scale.
you have to plate the steel with something else first - i think nickel, then chrome onto that.

[eccerr0r]

Re: Is this really LMP silver solder?

Now that goes back to the original question, what are the metal on the barrier strips made of, and why did Tektronix choose that... I guess if it is silver then those are expensive barrier strips... I don't think it's steel, especially chrome plated steel, that would be extremely hard to solder to. I've always thought steel was hard to solder to, but I recently was able to solder to some steel wire using Kester 44 rosin...

Incidentally speaking, someone has a vacuum tube Tektronix scope that doesn't quite work, I'll need to see if I can get him to let me fix it so I can play with the silver solder...

[stj]

Re: Is this really LMP silver solder?

i wasnt talking about the tek, it was just an example of why you see some metals.

[eccerr0r]

Re: Is this really LMP silver solder?

Ah okay. Thought you were implying that perhaps Tek had some layering to build those barrier strips, which is quite possible too.

Still would be interesting as to what it was made of it and why they specified that silver solder must be used... and how to know if you never heard that it was required prior to destroying one