# Soldering Iron question

#### Muttley600

Joined Jan 15, 2012
15
I have been using some old solder left over by my dad for years, creating perfect joints, I have had to buy more & it doesn't want to play ball?
It looks dull
I am using a 12/24v transformer he made years ago to run iron, I have always used 24v but new solder is thinner & just does its own thing, am I using too much heat? I have tried 12v but then it doesn't want to melt?

Thanks
Graham

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#### MrChips

Joined Oct 2, 2009
21,135
Nay. You should keep questions separate and start a new thread on a new topic. If you desire, a mod will come along and move it for you.

#### Muttley600

Joined Jan 15, 2012
15
Can a mod please move solder question into new thread for me, thanks.

I really do appreciate your help on this

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#### Muttley600

Joined Jan 15, 2012
15
Post not needed for this Q

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#### mcgyvr

Joined Oct 15, 2009
5,394
Solder comes in many flavors.. Your old solder was probably nice leaded solder (typical 63/37) and now you might have picked up a roll of lead free solder which requires slightly higher temperatures to work properly. The clue about it being dull really sounds like lead free as its usually duller looking than leaded solder.

#### DerStrom8

Joined Feb 20, 2011
2,390
It would help if we knew what kind of iron you had. Personally, I use a 15w pencil type iron, and 60/40 rosin core solder is usually what I use. I'm not sure you gave us enough information to really help you. What transformer are you talking about?

#### mcgyvr

Joined Oct 15, 2009
5,394
It really comes down to skill level.. I can take ANY soldering iron and solder with it using any of the common electronics lead and leadfree solder alloys. I've used everything from a cheapo 15W pencil iron from radio shack to weller/hakko units up to a 500W hexacon irons with tips that are about 1-1/8" in diameter. Soldering really is an art that takes some skill.. Keep your tips well tinned and clean, heat the parts you are soldering not the solder itself and practice..practice..practice.

#### thatoneguy

Joined Feb 19, 2009
6,359
The way you describe it, "just moves around and doesn't stick" sounds like a severe lack of flux.

Get some rosin flux from Radio Shack, or a flux pen from mouser or digikey.

And get Good Old Lead/Tin 63/37 Rosin core solder while shopping.

Do not use Plumbing Flux/Acid core solder on electronic circuits, it will corrode everything greenish and then fall apart. Use only Rosin or a flux designed for use with electronics.

#### DerStrom8

Joined Feb 20, 2011
2,390
The way you describe it, "just moves around and doesn't stick" sounds like a severe lack of flux.
It could also mean the iron is way too hot and not tinned properly. Make sure you tin the tip of the iron WHILE it is heating up. Otherwise the solder will just ball up and not flow properly.

#### Muttley600

Joined Jan 15, 2012
15
Thanks for all your replays guys, kinda got caught up explaining myself in about different thread, now getting grief for being on computer late...sigh
I work funny hours so willbe back on tomorrow night to answer all q's
Replies are gratefully accepted
Regards
Graham

#### Muttley600

Joined Jan 15, 2012
15
It would help if we knew what kind of iron you had. Personally, I use a 15w pencil type iron, and 60/40 rosin core solder is usually what I use. I'm not sure you gave us enough information to really help you. What transformer are you talking about?
My dad used to do electronics back in the 60/70's, he made his own transformer that is either 12/24v but having a look at iron might explain things a bit

This is the iron yes, I just noticed it was 24v

Do I buy new tips to see if that helps, which is best from these if I'm going to get some spares

The solder is 40 tin/60 lead but doesn't say about flux 1.2mm

Solder I brought was 3rd from bottom of page here

And get Good Old Lead/Tin 63/37 Rosin core solder while shopping.

Do not use Plumbing Flux/Acid core solder on electronic circuits, it will corrode everything greenish and then fall apart. Use only Rosin or a flux designed for use with electronics.
I don't suppose you have a link do you

Thanks for your help so far guys, seem to be rushing this week with lots on at work as I have next week off

Joined Dec 26, 2010
2,148
Tip size is mainly a matter of what job you have in hand, but preference comes into it. For some reason, beginners often seem to like smaller bits (and irons). More experienced users and professionals may use somewhat heavier tools, except for really sub-miniature work.

Clearly the point heeds to be small enough so that you can heat one thing at a time, but thick enough to supply enough heat. You may find that you need fine and coarse tips for different work. I have used these irons and generally prefer the cone-shaped tips.

Temperature is more a question of the solder used. The Weller bits in the No.7 range may suit best for leaded solders, and last better. They also tend to stay tinned longer, because the layer of solder on the end of the bit oxidises more slowly. If you are having trouble with bit de-tinning and solder balling up, it may be worth trying a cooler bit.

No.8 or No.9 tips may be better for lead-free solders, but the hotter bits may give more trouble of the kind you describe. It may be worth checking that the iron thermostat is in fact working correctly. If it is, the iron should be heard to click on and off.

Apart from assuring that you are using rosin flux cored solder, and possibly using extra flux, consider getting an active flux-based tip cleaner (these often come in small aluminium tins). Also use a damp tip cleaning sponge regularly during use to wipe the tip - a good soldering iron stand should be fitted with one. Please make sure that you have a decent stable iron stand, by the way - they make life so much safer.

#### DerStrom8

Joined Feb 20, 2011
2,390
The solder is 40 tin/60 lead but doesn't say about flux 1.2mm
Are you saying the solder is 1.2 mm? That's kind of big for most electronic circuits. I use .032" (about 8 millimeter) 60/40 rosin core solder from RadioShack. You can probably find it cheaper online, but that is the size I use. If the solder is too thick, it will not melt all at once and just won't flow. I used to have solder about the size of yours by accident (I picked up the wrong stuff), and it ended up creating kind of a cold shell around on the tip, because it wouldn't all melt.

Joined Dec 26, 2010
2,148
Are you saying the solder is 1.2 mm? That's kind of big for most electronic circuits. I use .032" (about 8 millimeter) 60/40 rosin core solder from RadioShack. You can probably find it cheaper online, but that is the size I use. If the solder is too thick, it will not melt all at once and just won't flow. I used to have solder about the size of yours by accident (I picked up the wrong stuff), and it ended up creating kind of a cold shell around on the tip, because it wouldn't all melt.
Unless you are using a really tiny bit, solder of that thickness should not in itself be that much of a problem. Solder formulation, flux, and especially tip cleaning and tinning seem much more likely issues. I have used Weller irons of the type the OP is discussing: they are normally more than capable of melting this thickness of solder, provided that the tip is properly tinned and that solder of a reasonable melting point.

Note that unless the tip surface is visibly tinned, you are likely to have trouble. A tarnished or blackened tip face will not do.

If you are using a high temperature lead-free solder it may be more important to have it in a thinner gauge, but then it may be even more important to use a higher bit temperature.

#### thatoneguy

Joined Feb 19, 2009
6,359
I get my stuff from digikey, 1lb spool of kester 0.22" for general use, and a 1/4lb of ChipQuick 0.20" for SMD work.

Here's a flux pen I use

The best solder for SMD and all purpose, but spendy. Chipquick, I use the 63/37

Ignore the solder paste, they are for re-flowing surface mount with a reflow oven, hotplate, toaster oven, or hot air pencil.

Paste Rosin can be found at Radio Shack, a pretty good size jar of it for like $8, about$2 over best online price. Apply with pointy end of toothpick before adding solder and heat, the solder will jump to wherever you put the flux, literally.