What Type of Solder Should I Use?

[superscott319]

Hey everyone, I'm Scott. 

I just started learning how to solder and after watching some tutorials, put aside some spare PCB boards I had lying around to try my hand at soldering with, but ended up performing what could be one of the worst soldering jobs ever with big globs of partially melted solder and burn marks all over the board. I'm pretty sure the cheap solder I was using had something to do with it, but being this is the first type of solder I've ever worked with, I'm not completely sure.

After watching Dave's How to Solder Part 1 tutorial, I realized the type of solder you use makes a big difference and so I was wondering if you guys could point me in the direction of what types of solder would work best for general purpose PCB soldering.

I was using a good quality iron but the solder I was working with was some unnamed .031" stuff that came with a cheap PC repair toolkit. It was really hard getting this stuff to flow even when setting my iron to a higher temp. I don't have other solder available to test whether it's my iron or the solder.

From what I understand so far, the thinner stuff is better but I'm confused when it comes to the types of flux cores available. When looking to buy some thin 60/40 or 63/37 solder, the specs different sites and brands showed for flux didn't follow a consistent format where some mentioned having a number of cores while some didn't even mention cores at all or described it as "pure core".

I saw in Dave's EEVBlog tutorials, he used some five core solder but does the number of cores play an important role for good quality soldering or is there more to it than that?

Thanks for helping clarify this.

[nanofrog]

Good supplies really do make a difference.

The number of cores (where the flux is located; could be 1+, which is what the confusing information is about), isn't as important as good flux vs. crap IMHO. Additional cores do tend to help reduce splatter (air bubble causes the molten solder/flux mixture to "pop" and singes your hand if it makes contact). But the number of flux cores isn't critical for making good joints.

Brands such as Kester, Multicore, or AIM would be what you want to go with (they make flux and solder, as well as flux cored solder wire). As per flux, either good quality rosin or no-clean formulations work well for hobbyist use (recommend avoiding water soluble, as it has to be cleaned off quickly or it will corrode joints and exposed pads/traces).

Get some additional flux and use when necessary, rather than just relying on the flux core in the solder. For example, adding a bit of additional flux to a wire for tinning tends to improve the results in my experience (you'll figure it out in practice). Also necessary to add additional flux for drag soldering IC pins (reduces bridges between pins).

[superscott319]

Thanks, that information was very useful.

I looked up the brands you mentioned along with some other widely used ones and noticed each brand has a huge variety of solder types to choose from. One thing I noticed was very few of these solders made any mention of how many cores it has. Is that because the number of cores just isn't a significant enough spec to mention or am I overlooking something?

[nanofrog]

Is that because the number of cores just isn't a significant enough spec to mention or am I overlooking something?

Multicore is the only company I recall that's really made anything of the flux core count. Not a big deal IMHO, and wouldn't worry about it. The quality of the flux and alloy is far more important to make a good joint, and should be the primary concern.

[David_AVD]

What temperature did you have your iron set to?  Also, what type of iron is it?

[ddavidebor]

stannol is also a very reputable brand.

every brand usually has the same alloy with very different flux inside, from the shy little flux who only work on new board, to the apocaliptic destruction flux for repair 40yo things.

you should probably whant something in the middle. even a top brand stannol kristal is pretty useless in his less powerful version, and the most powerful is too corrosive and require whashing if you expect your board to last more than a few year.

just watch on they're catalog

[superscott319]

Is that because the number of cores just isn't a significant enough spec to mention or am I overlooking something?

Multicore is the only company I recall that's really made anything of the flux core count. Not a big deal IMHO, and wouldn't worry about it. The quality of the flux and alloy is far more important to make a good joint, and should be the primary concern.

Ok thanks for that advice.

What temperature did you have your iron set to?  Also, what type of iron is it?

I went up to 480c and still had trouble getting the solder to flow. The solder would just become brittle and chip off from the wire instead of melting. The soldering station I'm using is a X-Tronic 4010.

[Sergei]

I went up to 480c and still had trouble getting the solder to flow. The solder would just become brittle and chip off from the wire instead of melting. The soldering station I'm using is a X-Tronic

My first question is did you tinned the tip and is everything tight.  As 480°c is equal to 900°F you shouldn"t have any problem melting the large solder unless your not getting good heat transfer or using the wrong type. Also try using a brass brush to clean your tip, that what I use to clean my Ungarmatic elements. For PCB work I use Kester "44" Rosin Core solder.

[superscott319]

I went up to 480c and still had trouble getting the solder to flow. The solder would just become brittle and chip off from the wire instead of melting. The soldering station I'm using is a X-Tronic

My first question is did you tinned the tip and is everything tight.  As 480°c is equal to 900°F you shouldn"t have any problem melting the large solder unless your not getting good heat transfer or using the wrong type. Also try using a brass brush to clean your tip, that what I use to clean my Ungarmatic elements. For PCB work I use Kester "44" Rosin Core solder.

Yes, I make sure to tin my soldering iron tips before using them, although I wonder if my iron is properly transferring heat. When looking at the heating element and internal wiring of my soldering iron, everything appears to be in good shape. Is there a way to test whether the temperature of the tip is consistent with what I set it to?

Also for cleaning my tip, I'm using the sponge which came with this soldering station. Over time I've noticed some of my tips starting to become oxidized. Perhaps that is causing heat transfer issues. Do you recommend using a brass brush over a sponge and is there a way to restore my oxidized tips?

[David_AVD]

The usual causes for "blobby" soldering is temp too low (not the case here) and not letting the two surfaces (that you're trying to solder together) heat up enough before adding the solder.

A typical solder joint sees the iron tip contact both surfaces at the same time.  Only then does the solder get introduced to that (3 way) junction.  When enough solder has been added, pull the solder wire away from the joint followed by the iron tip.

[Sergei]

Also for cleaning my tip, I'm using the sponge which came with this soldering station. Over time I've noticed some of my tips starting to become oxidized. Perhaps that is causing heat transfer issues. Do you recommend using a brass brush over a sponge and is there a way to restore my oxidized tips?

I always clean my tip with the brass brush and have a can of Kester soldering paste flux SP-30 that I can put the tip into before any soldering. Not a real big fan of the sponge.

[ddavidebor]

yeah use the sponge without destroy the world require a few year experience

[Stonent]

If your surface is dirty with oxides (tip or joint) it won't heat very well.

Multicore seems to be the brand I've seen Dave using in his videos. They are from Richardson, TX sort of in the more high-tech area of Dallas County. (Not too far from the TI main office and ST Micro's North American HQ)

[KWuensch]

I would make sure your soldering iron is at the right temperature. Maybe you will need to turn the temperature up a bit more.

For solder AIM is a good brand, here is a link to several types of solder they have that I found online: http://www.gotopac.com/Wire_Solder_s/1106.htm

You may also want to use some extra flux too. That may help a bit. But really practicing will really make a big difference so find as many things to practice on a possible.

Hope that helps.

[Monkeh]

I would make sure your soldering iron is at the right temperature. Maybe you will need to turn the temperature up a bit more.

For solder AIM is a good brand, here is a link to several types of solder they have that I found online: http://www.gotopac.com/Wire_Solder_s/1106.htm

You may also want to use some extra flux too. That may help a bit. But really practicing will really make a big difference so find as many things to practice on a possible.

Hope that helps.

I find it most interesting that all your posts on the forum are about how you 'have found' products online. From one shop.

[ddavidebor]

Yeah if yo are a seller please change your name in the one of the shop or company you write for and write in a stile like a professionist... "[...]that's our suggestion... If you want, we sell a solder you might enjoy"

we like seller in this forum, just, everyone must understand you are a seller. Just be present here as a seller will improve your earning because people thrust people that are on this forum. Nobody thrust a online shop of you don't thrust the seller.

[mrflibble]

Well, thrusting the seller might be warranted in some cases, but did you check the pricing to get something to LEO? Still $10k++ per kilogram. O_O

[ddavidebor]

Leo?

[mrflibble]

Low Earth Orbit. Thrust the seller. get it?

[ddavidebor]

So i hope