[Toe]

Was just looking over Handmade Audio and I notice they've got a solder I haven't heard of called Qualitek. Handmade claims it's "equal to Kester". The price ain't bad - $13.75 for a half pound spool. Anyone know if this stuff's any good?

 

[Gariver]

At Mouser.com, you can get 1/2 lb. of Kester "44" solder in an eutectic mix (Sn63/Pb37), with a 0.025" diameter, for only $8.50! That's a better deal for a much better solder. You save $5.75, and you get the best solder available for DIY electronics.

Now, if you buy the 0.031" diameter Kester "44", then 1/2 lb costs only $7.80! That, of course, is quite a bargain. The only drawback here is that the 0.031" diameter is a little bit harder to work with (too thick). But if you must save $$$, this is the one to get! It's very, very cheap!

Here's Mouser's part numbers for these eutectic solders:
Kester "44" with 0.025" dia: 533-23-6737-18 = $8.50 for 1/2 lb.
Kester "44" with 0.031" dia: 533-23-6337-27 = $7.80 for 1/2 lb.
http://www.mouser.com

NASA uses Kester solder for their critical electronic applications. So it is highly recommended.

Another point to remember: That easiest way to avoid cold solder joints is to use eutectic solder (63/37). Eutectic solders do NOT have a pasty state. They go from liquid to solid instantly. That assures you a fine grained, solder joint that works perfectly every time.

Eutectic solders melt at a slightly higher temperature than 60/40. Thus, you do need a hotter soldering iron. However, a 25 watt iron with a tip temperature of 750 F or slightly more will be enough.

BTW, silver solders with Sn62/Pb36/Ag2 mix are also eutectic solders. This is a great solder also. The problem here is that Kester does NOT offer this solder in 1/2 lb roll. You must buy a pound for $26.80 in the 0.025" diameter (Mouser part#: 533-24-7150-18).

Cardas Quad Eutectic Solder...
That's the solder I use, and it is available from Michael Percy. It's a great solder that gives perfect solder joints every time. I never get a cold solder joint with this superb solder. The "quad" part of the name refers to the 4 metals used in the solder: tin, lead, silver and copper! The cost of this boutique solder is $21.00 for 1/2 lb and $11.00 for 1/4 lb at PercyAudio.com! Cardas.com recommends a 25 watt soldering iron with a tip temperature of 750 F for this solder.

http://www.percyaudio.com

I also use the Kester "44" mentioned above. In four decades, Kester has perfected the "44" and made it into a very fine, reliable solder. Use it with a 700F soldering iron (minimum). Hightly recommended for newbies!

Good luck with all this info!

 

[Toe]

Wow, I guess I haven't shopped around enough for solder!

I was just looking at Welborne's price of $90 for a pound of Cardas.

Is there any place else that can compete with Percy's price on the Cardas? I've always been reluctant to buy from him, given how many times I've heard people say he's outrageously slow...

And while I've got a soldering thread going, I could use a new soldering iron too. Can anyone reccomend a decent soldering station for, say, $50? (or less)

 

[Gariver]

Weller's new, low-price soldering station, model WLC100, has dial adjustable power (5 to 40 watts), and it is able to reach 850-F. That's more than enough for eutectic solders. The WLC100 also has a replaceable heating element, sponge and soldering tips. Thus, you can keep it working for many, many years. Nice!

Hosfelt.com sells the WLC100 for around $36.75! That's a very good price. The same soldering station goes for $44.75 at PartsExpress.com.

Check out the Weller WLC100 at Hosfelt.com...
http://www.hosfelt.com/Weller%20folder/Weller%202.htm

Michael Percy will ship out a couple of items fast if you tell him it's very urgent. However, if you order several items, don't expect a fast order. It has to be 2 or 3 easy items, and you have to say it is very urgent.

Wonder Solder...
Michael Percy also sells Wonder Ultra Clear Solder, a highly regarded eutectic solder used by many high-end manufacturers (Audible Illusions). Recently, I learned that Wonder solder has small percentages of both silver and gold in it (Ag and Au). Hmm...interesting! Wonder solder sells for...
--1/2 lb = $24.00
--1/4 lb = $13.00

I have never ordered from Hosfelt. So I don't know what to expect from them. PartsExpress, however, is very reliable.

 

[tangent]

750 degrees!! Yow. That's just begging for parts damage. Commercial assembly is generally kept below 500 degrees F. (<250C) I go a little higher since that lower temp is for wave soldering, and with hand soldering you can get away with a higher temp if you're quick with the iron. Higher temperatures are nice for quick solder melting, but you have to balance it against the danger of parts damage and iron tip oxidation.

For solder, I use the Kester 44 with silver, for what it's worth. Although I must say, despite the high volume of soldering I do (for a DIYer) I'm probably not even halfway done with my 1 pound roll and I've had it for at least half a year. For low-use DIYing, half a pound is more than enough. I wouldn't go lower than that, though. Below the 1/2 pound level you get high-cost-per-pound stuff like you find at Radio Shack.

By the way, the Kester 44 with silver is not eutectic. It's close, but there's still a short pasty state. I don't get cold joints, but I don't know if that's because it's close enough to a true eutectic or if my technique is simply good enough to avoid them.

I don't know if the Cardas blend is truly eutectic -- the addition of the copper might bring it back into balance.

 

[Gariver]

After I bought my 1/4 lb of Cardas Quad Eutectic Solder from Percy for $11, I e-mailed George Cardas for tip temperature recommendations. His wife replied and said that at Cardas they use 25 watt soldering irons with tip temperatures of 750F. She said that's the temperature used for soldering their audio cables.

Cardas solder is indeed an eutectic solder. Heat it up and it gets as liquid as water. Pull away the soldering iron, and it quickly solidifies. Love it! You can see that when this solder is liquid it is almost double the size as when it is solid. So the solidification process has a fast, shrinking force to it.

I highly recommend this solder. It's just $11.00 for a 1/4 lb. In my view that's not too much. Where to buy? Go to Michael Percy's site. Percy has the best prices for Cardas solder.

http://www.percyaudio.com

Ron Welborne at WelborneLabs.com wants $90 for one pound of Cardas solder. That's way too much. You can get two 1/2 lb rolls (one pound) at PercyAudio.com for $44. Ha!

Soldering Heat-Sink Clips...
You clip the pieces you are soldering to draw the heat away from the parts you solder! You can avoid damaging heat-sensitive parts with these clips. Mouser.com has 2.5" aluminum clips for this purpose (part# 384-1017). They cost $0.75 each. Get two for $1.50!

On High Temperatures...
If you think 750F is very high, try 800F. I once read an article about Wonder Ultra Clear Solder that recommended this very high tip temperature. WOW!

Edit:
I just found Wonder Solder's site. For optimum flow of their solder, they recommend a tip temperature of 750F. That's exactly the same tip temperature recommended by Cardas. Hmm.

Here's Wonder Solder's site...
http://members.aol.com/trtwonder/

 

[Gariver]

I found a page at Kester.com with specific recommendations for hand soldering. For Kester "44" eutectic solder (63/37), you should have a tip temperature of 700F. Silver solders require a slightly higher temperature. What temp? Try to use a tip temperature between 700F to 750F. Of course, the best way to find the right temperature is to experiment at home.

http://www.kester.com/faq_hand_soldering.html

Tangent:
You try to get a temperature that does NOT have a pasty state. Your Kester "44" with a Sn62/Pb36/Ag2 mix is indeed an eutectic solder. Maybe you are getting a pasty state with a tip temperature that is not high enough. Over at AudioAsylum.com, both Jon Risch and John Curl have repeatedly stated that Kester Sn62 silver-solder is an eutectic solder.

Learn something new every day...
Notice that Kester's "44" and "245" solder do NOT have to be cleaned. Kester says that the flux remnants are NOT corrosive or conductive. Therefore, cleaning the solder joints is done for appearance purposes only. Hmmm...interesting!

Good luck with this info!

 

[tangent]

Soldering connectors isn't terribly relevant to soldering electronics. In soldering wires to connectors, you have to quickly heat large blocks of metal that are often themselves heatsunk by virtue of being bolted to a thick metal panel. Speed is important in a factory setting where time is money. But in that Cardas factory, I'd be surprised if they hand-solder their electronics to begin with.

I also don't buy the argument that if you get your solder hotter, it will somehow not have a pasty state, since that's a matter of cooling. No doubt it probably does flow better when hotter, but I don't find that it flows poorly at my preferred soldering temperatures. And I certainly do enjoy not having my iron tip visibly cloud up with oxides as soon as I pull it off the sponge.

As for whether Kester's silver-bearing solder is eutectic, I'm probably stretching the definition of "pasty". It doesn't have that long pasty state like 60/40 solder, for sure. And as I said, I don't get cold joints with this solder, but I can't tell you whether it's because of my technique or because there is indeed an instant hardening going on.

And as for cleaning the goo left behind by Kester 44 -- that stuff may be neutral, but it's very sticky and it will attract dirt and grit which may have their own effects. I always clean my boards.

 

[Gariver]

OK! We disagree on tip temperature, and it is useless to argue! If you want to use a 500F tip temperature for an eutectic solder, go right ahead! That's what works for you!

Most manufacturers recommend tip temperatures of 700F to 750F for eutectic silver solders (Sn62/Pb36/Ag2). However, there's no law forcing you to follow these recommendations. Do as you please in this respect.
--Cardas 750F
--Wonder 750F
--Kester 700F

Of course, with these temperatures, it is wise to use the clip-on heatsinks. That's the best way to avoid damaging heat-sensitive parts. Here's Mouser part# for clip-on heatsinks: 384-1017 for $0.75 each. Buy two!

BTW, in my email to George Cardas (George@Cardas.com), I asked him about tip temperatures for DIY electronics, not for soldering Cardas connectors. I was very specific about that! Another point: Cardas solder does NOT leave too much residue to clean up. Nice! And a final point: Is it a true eutectic solder? It sure is! It does NOT have a pasty state at all! That's why I like it!

Did the people at Cardas lie to me? No! I don't believe they did. When they said: "At Cardas, we use 25 watt soldering irons with tip temperatures of 750F", I believe them. Why would they lie? Hand soldering is still going on at small firms like Cardas. On the other hand, big firms, like SONY, no longer do hand soldering.

Howard H. Manko's 485-page book on solders and soldering has all the answers on the subject. Be sure to read what Manko says about eutectic solders. I did!

http://www.ebooks.com/items/item-display.asp?IID=19311

That's the soldering bible of the electronic industry! It's very, very complete!

 

[Gariver]

Howard Manko's book sells for $79.95 new. That's quite a bit of money for a soldering book. However, right now, Powells.com has Manko's book used for only $26.00. That's more affordable...

http://www.powells.com/subsection/MetalWelding.html

Every once in a while, you can also find it at ABEbooks.com...
http://www.abebooks.com

 

[chai138]

Qualitek Solder is one of the leading brands used in the high-end micro-electronic assemblies. It is probably 1 out of 3 solder manufacturers still Made in America. Others like Kester are made in Mexico. You can find their products sold at Fry's electronics and they offer a small dispenser pak packaging that fits into your pocket and retails for ~ $2.00.