[Closed] learning to solder?

Just dont ask any Americans!

Sawder ffs! Just no! 😆

firstly, is there an easy way of working out the right ones to heat up?

If it's not obvious, get a ruler an measure from the edge.

thirdly, the capacitor has real long legs. do i push it through melted solder then snip off to length?

No, remove the old component and solder. Trying to use the old solder sounds like it would be quite hard.

Also - get a solder sucker, you will need it to remove the old solder when you remove the damaged capacitor.

Get a solder sucker,do a few dummy runs on an old bit of board before you launch in to the job.Make sure everything is clean and use a good flux.

[img] [/img]

Edit: misread thread title. Solder. As you were.

You get stuff called Solder Wick - it's basically a fine mesh tape. Press that onto the old solder with a hot soldering iron and it'll wick it all away. Easier than a Solder Sucker IME.

http://www.maplin.co.uk/p/de-soldering-braid-1mm-width-n47fx

When you remove the capacitor make sure you note the polarity - if it is a blue can type capacitor then one side of the can will have a stripe down it. Make sure you put in the new capacitor the same way round or it will go pop.

[img] [/img]

Oh and loads of decent vids on YouTube for technique - but it's really not rocket science. Only important thing to know is that you make the metal hot then apply solder to it, you don't melt the solder on the iron then apply it to cold metal.

As others have said, get a solder sucker.

Also use new solder to refit cap

Use tweezers to pull out, but don't use force, the cap after you have removed the solder as it will be very hot.

Is it an electrolytic cap, if so you need to make sure it goes in the right way. It will have a "-" on one end to show you.

Use solder wick... put the wick on the pad then apply the iron tip, do not leave the iron on any longer than is needed to pull the liquid solder away otherwise you'll delaminate the pad from the board. The hole needs to be clear of solder then insert the new component. apply the iron to the leg and pad at the base and feed in the solder (most solders are fluxed these days), again as soon as the solder takes to both remove the iron. snip the excess legs and away you go. REMEBER too much heat is bad!!!!!.

thanks. been looking at usual places and can see the soldering irons, but no sucker or braid.

could anyone link me to an iron, flux and either braid or sucker from either toolstation, screfix or maplins at all please?

itd be good if i could get everything from one place.

thanks a lot

maplins N49FX for braid, N11BY for a cheapo iron, you can also get a bit of solder there too.

excellent, thanks.

and yeah, whats that american sawder thing all about 😀

Last time I got solder from Maplin they only stocked lead-free, which is all very nice for the environment and that, but leaded solder is MUCH easier to use especially for a hobbyist.

Have you looked to see how much a new circuit board would cost?

It might be cheaper than buying all the equipment

Trying to use the old solder sounds like it would be quite hard.

could anyone link me to an iron, flux and either braid or sucker from either toolstation, screfix or maplins at all please?

Electrical solder (as opposed to plumbing solder) has a flux core so you shouldn't need to buy separate. This is also why you can't just reuse old solder, the flux will be burnt off as part of the soldering process so you need to remove it and use fresh.

Or just ask a capable and willing STWer to do it?

Where are you located?

new circuit board is around £80 i think the missus said. got now to lose trying the 50p capacitor and also learn new skill/ acquire new tools for future 🙂

i assume i just tell em what im doing in the shop and theyd supply the right solder yep?

ta

EDIT:

Where are you located?

Don't get into a conversation with an American about circuit boards they use an entirely different naming convention (well not quite but still can cause a lot of confusion) 🙂

Use tweezers to pull out

It's often easier to snip the old component and then desolder the legs individually. Trying to do both at once means that the one you've just desoldered could 'stick' whilst you're doing the other.

When using the iron, use it for a couple of seconds at a time and then wait 30s before trying again. Too much heat and you can lift the tracks off the board, then you're in a world of pain.

What I'd do if I were you is get a strip of Veroboard and a bargain bag of resistors and practice before going anywhere near a repair.

It's pretty easy, but you will need to get some practice on experiencing how the stuff behaves.

Electronic solder is just solder, flux core meaning there's flux down the inside of the wire, you don't have to add it like you do with the stuff plumbers use.

Buy some veroboard, a kit, and make something pointless as practice.

If I were removing a capacitor, I'd pull the leg with fingers or tweezers whilst heating that leg. Doens't work with things like chips or PCB mounted sockets that can't be flexed, but should work with a cap.

Have you got an equivalent capacitor? Needs to have the same capacitance and [i]at least[/i] the same voltage rating.

Also check the other caps while you are there - any that are swollen are also on their way out.

It's often easier to snip the old component and then desolder the legs individually. Trying to do both at once means that the one you've just desoldered could 'stick' whilst you're doing the other.

Here's a tutorial from my 6yo...

My top tip for desoldering - if you're having trouble sucking all the solder away from the legs/hole, try adding a bit more solder first.

Nice work gerti! She's doing really well! 😀

My 6yo has put together a couple of little kits from Maker Faire etc (flashing badges and the like) but she's a lot more hesitant than your little one.

(Probably didn't help that the first time she tried it she put a nice big apprentice mark on my finger 😀 )

well she can certainly solder better than me thats for sure!! cant even desolder yet!

been to maplins, bought an iron, solder wire and desolder braid, plus a little practice board.

tried the braid, but i just cannot get the solder to melt onto it. if i put a bit of solder onto the iron it melts and smokes, so its hot enough. cover the old solder with braid, press the iron onto it but its not bringing up the old solder. just out of interest i pressed the iron onto the back of the dodgy capacitor but it doesnt seem to be melting any old solder around it, even without the braid.

capacitor is still solid in board.

Don't use the iron dry when desoldering, you need a dot of solder to conduct the heat to the old joint.

Can't help with the braid, I've never used it.

OK best thing to do is put some fresh solder onto the pad/leg then use the braid to remove the lot, also wetting the braid with fresh solder can help.

Yeah you want a little bit of solder on your iron to help make good contact and transfer the heat well. Called "wetting the tip"*

It's also possible there is a finish on the board, like a varnish, to help protect it. So try giving the old solder a little little scrape with a stanley first.

.

* (just the tip mind. And only for a minute.)

Braid is shit - use a solder sucker. Also - make sure you have a wiping sponge - this is NOT a regular sponge, it must be designed as such or it will melt.

I am assuming your capacitor is:

*Of the same type [electrolytic/ceramic/tantalum etc]
*Of equal or higher voltage rating
*Of the same capacity/value
*Going to be put in the same way around if necessary [nearly all electrolytic caps are polarised]

If I were you I'd definitely practice - just get yourself an old circuit board with similar things on it and practice removing them without buggering it up.

Tip:
Don't fight it when removing - if you wrestle too much [joints cooled/ leg jammed on hole etc] you can strip the traces off the board.

Bonus tip:
When you're all finished apply a good amount of new solder to the tip, dabble it in the liquid clean solder and then flick/wipe it off. You can do this on cardboard, and means the tip will finish with a protective coating of solder and flux and not rot.

Braid is nicer to use than other desoldering methods imo. I think proper solderists possibly don't use it because it's wasteful, and a bit of a crutch, but for your purposes that's not important really. For the amount of soldering I use it's ideal

It's also possible there is a finish on the board, like a varnish, to help protect it. So try giving the old solder a little little scrape with a stanley first.

I am assuming your capacitor is:

*Of the same type [electrolytic/ceramic/tantalum etc]
*Of equal or higher voltage rating
*Of the same capacity/value
*Going to be put in the same way around if necessary [nearly all electrolytic caps are polarised]

whats happening at the moment is i hold the solder to the iron to 'wet the tip' but it doesnt melt, then it does all at once and leaves a round blob on the end of the wire, my iron doesnt actually seem to hold any.

it may be easier if i scrape the surface of the board first then. and im also practising but not having much success with braid or solder with that either. maybe im just sh1t 🙂

my iron doesnt actually seem to hold any.

It's dirty. Gets fouled up with burnt flux and who knows what. When this happens, sand the tip back to shiny copper. Then when the solder touches it it'll flow over the surface and make it silver. This is called 'tinning' btw, and it generally really helps soldering things if you tin both bits first (ie get solder to flow onto the surfaces) and then you'll only need to add a tiny bit of solder.

However in terms of electronics, most stuff is designed to be soldered so this isn't so necessary when you're sticking legs through holes. But you WILL need to scrape the green/brown stuff off to get shiny metal, if there's no solder on it already.

Solder sticks to surfaces by making an alloy with the metal where it contacts it. Which is why you can only use normal solder on some metals, and you need different solder for others. For this to happen, you need clean fresh metal surfaces.

Brings back memories of the 70's building a "computer" with my Dad 🙂

All good advice above .. once you are on a roll you will be tempted to replace solder joints all over the place

Also - make sure you have a wiping sponge

One of these:

[img] [/img]

whats happening at the moment is i hold the solder to the iron to 'wet the tip' but it doesnt melt, then it does all at once and leaves a round blob on the end of the wire

Lead-free solder by any chance?

It's dirty.

Lead-free solder by any chance?

also scraped the surface with a stanley, its scraped a bit of something off, but i still cant melt that solder and i dont want to leave the tip on for too long.

Worth mentioning, some irons are nickel coated, and you're not supposed to sand it back. Everyone does anyway, because you only realise it was nickel coated after you've already sanded it back. But still.

One of these:

Edit: Also prefer suckers to braid for removal as I find braid doesn't work too well with small tips.

its new, just bought it! and yes, maplins only sold lead-free.

The last time I bought a new tip (decades ago) it took me ages to get the first tinning to stick.

Not that it really matters but I own a PCB assembly company and shown this to our senior assembly engineer.... He's not normally a sweary bloke!! 😆 😯

What were his complaints marcus?
Always keen to learn.

You may be struggling with desoldering the holes as one may be an earth plane - takes more energy to melt the solder. Doesn't look like a multi layer board to me. Earth planes in the middle are not nice. Quick and dirty method is to use a wedge tip, use enough solder (or a wire link) to bridge the holes and then wiggle the cap whilst heating. You can then pull it out, and reverse the process whilst fitting the new cap. If your iron is shit though that may be a challenge.

Which iron did you buy.

I'm no expert but just going from my 8 quid cheapo 28watt to a 60watt solder station made proper solder work possible.

My previous one just never got hot enough to do much more than melt solder if touched direct and laid on. So wrong but it was fine for wire joins.

Much easier now with a proper powered iron can get heat into the joint and feed the solder in like I was taught.

Which iron did you buy.

twas [url= http://www.maplin.co.uk/p/maplin-30w-mains-soldering-iron-n38ac ]this one.[/url]

looking at the reviews i wish id gone for a different one now :-/

30W a bit too much for electronics, I was always told.

25W for me no problems.

If the Flux is smoking, the iron is too hot...

Most PCBs have components surface mounted so you stand little to no chance of extracting and/or replacing individual components (even if you could detect which ones actually need replacing). Most boards are just replaced as a complete unit.

But...if you can isolate the faulty component and you think you can replace:

1) Don't use too much solder!
2) You need to get a nice flow of solder from the soldering iron onto the leg of the component.
3) Overheating the component will destroy it.

It's a fine art and I'm no expert - but practice makes perfect!

Doesn't look like a SMT board though - and I think he's identified the faulty component already? As the board is a bit blackened I'd go with an electrolytic cap that's gone short, so you could measure with a DVM. Boards are replaced as a unit because labour isn't cost effective in this country. SMT components are generally easier to remove than thru-hole, as you can swipe them off, wick the pads flat then replace. To be fair, I do have a lot of experience so maybe I think it's easier than it looks. Totally agree with lead-free solder being an arse mind. And because the irons were consuming more power not a net environmental benefit either 🙁

i'm starting to learn to solder myself, although i've got myself a quad 303 amp to play with not a washing machine ; )

this is the desolder bargain of the year...

http://www.maplin.co.uk/p/white-box-de-solder-pump-n91ll

and this is a bit of a gem too...

http://www.maplin.co.uk/p/the-art-of-soldering-cj23a

after much looking and reading i bought an antex XS25 and a couple of extra tips of varying sizes, about 20quid delivered i think after shopping about. tips from ebay. but i can already see that if i get very keen i may well go looking for a nice used soldering station set up.

i need a stand now as well and funnily enough had just come across the metal sponge things myself so reckon thats what i will buy. cleaning the tip and keeping an eye on the tinning makes heaps of difference, i never knew to do that before.

for practice there are little diy kits full of parts on ebay for about 99p from china. i bought a mono amplifier to work on soldering and desoldering.

related but not specifically soldering, i also read electronics for dummies last winter. search on google and you will find earlier versions on pdf. i liked it and now intend to buy the latest expanded version for reference and to work through the projects in there.

then i'll set to on the quad... what can possibly go wrong!

I bought the aj55 from maplin.

Heats up in 30 seconds.

I need more heat than a 28w could provide as it seems I'm often soldering late at night outside in the sub zero.

I had to buy a new one after my cheapo wouldn't melt solder to let me repair my fog light switch at 1am the night before mot 🙁 ended up using a mapp torch on low to repair it.

Oh and like the idea of diy kits for practice.

I'll go have a look as my soldering could use practice. Been 15 years since I learnt and since then the extent has been jointing wires.

This thread has made me think about projects again. I fancy building a bass guitar amp.

Sorry, didn't read through the entire thread. If you suspect a cap has blown (which you can easily spot as they tend to "bloat") you can snip from the top of board, heat gently, and push through revealing the empty holes. Remember to observe polarity before you remove and replace.

this is the desolder bargain of the year...

after much looking and reading i bought an antex XS25

I have that XS25 iron. It's seems okay to me (light electronics work) - it does struggle a little on things with lots of metal or heat sinks on them though and the plasticy lead is really bloody annoying (apparently there is a version with a silicon lead that is meant to be much better).

If you are looking for electronic components rather than whole kits then I can recommend this eBay UK seller:
http://stores.ebay.co.uk/abxlabs/
Nice guy. Met him at Maker Faire UK (which is an event I highly recommend everyone on this thread goes to!)

Here's a nice little learn to solder video from Carrie Anne of Raspberry Pi fame:
https://www.raspberrypi.org/blog/learn-to-solder-with-carrie-anne/

Interestingly she was taught by someone called "Gert" - anything you want to tell us there gerti? 😀

Op

I've not read all the posts here but just wanted to check you're not doing any of the psu caps are you? or poking around that part of the appliance etc?

I'm only asking because you probably (by virtue of not being able to solder or identify the faulty component through visual means or using a mm) may not be aware that the psu section of an appliance needs to be treated with care.
I know **** all about washing machines but know psu's well. If there is an issue with the bleed cct it is conceivable there's enough charge stored in the caps (dependant on its design) that will at best give you a entertainingly good shock or at worst kill you. It is rare for the latter scenario but it is a possibility so thought it might be something worth bringing to your attention as a novice tinkerer..

Fair point. If it is a decent size cap then it's always a good idea to short across the terminals with an insulated screwdriver... I mean "a certified capacitive discharge device" 😉

got a washing machine playing up, and been looking online for solutions. seems to be a well-known fault with circuit board, replace capacitor C17 etc etc. i always try and fix things myself if poss, both for money saving and learning something new, so im looking at trying a 50p fix rather than a new washer.

Is this the flashing lights on the front of the machine scenario?

I changed the capacitor on mine a few months ago. All working fine. Solder sucker is the way to go.

Not that it really matters but I own a PCB assembly company and shown this to our senior assembly engineer.... He's not normally a sweary bloke!!

Do tell, I used to work in PCB assembly for defence electronics and radar companies, eventually was a production manager for a sub contract company...

Show us a pic of the cap and the other side of the pcb 🙂

Snip the legs of the old cap leaving a bit sticking up, solder new legs to old stubs, shorten the new legs first if space an issue.

Is this the flashing lights on the front of the machine scenario?

questions about whether im sure ive got right capacitor/board/other things i dont understand 🙂

Show us a pic of the cap and the other side of the pcb

[img] [/img]

underside of board.....

[img] [/img]

thanks

Bottom nuggets - joke's already been done.

😳

pic of cap, top right of the cluster of 4 at C17. and yes, it is slightly domed.

Yep that cap has had it.
Swollen up nicely and looks like a bit of electrolytic fluid might have already leaked out.

You can see that the polarity is marked (with a '+' on the board and the negative stripe on the capacitor).

update. decided that the stuff i bought from maplins isnt good enough for me as a beginner and its certainly not doing what i want it to with a circuit board so its a waste of money. took it back to maplins and got a refund.

gambled on taking the board to the one place in town that does this sort of thing, but lost the gamble when they said the bloke that solders retired 10 years ago.

so now i have no equipment, still got a dodgy PCB and a wife who's crying out for the washing machine 😀

ill have to ask around a few mates, see if anyone does it locally.

thanks

This guy is always good for a giggle while being very informative

A good section particularly of interest to trail rat at around 11 min in

I'd say post it to me and I'll do it, but I'm away on wed eve and not back till Jan so you'll have to be quick!

good news. took it to a mate, again we struggled to melt the solder on the board but got there in the end with a 2 pronged heavy duty type iron, and put a couple of blobs on a new capacitor.

looked a bit scruffy and didnt know if id ruined the board with all the prolonged heat from failed attempts but...... put it all back together and it appears to have worked 😀

so, ive learned something along the way, mainly that solderings a bit harder than i would have expected, and cheap equipment is basically not up to the job.

thanks for your help

Glad you got it sorted. And a new skill half learned.

Stick at it. It's kinda fun, but a bit of a rabbit hole (I'm just learning myself after decades of writing embedded software with very little idea what the electronics side was doing).

yep ulysse thats what i was getting at - my cheap 28w iron in the cold working on wire couldnt heat the work piece up enough due to a lack of heat.

it was very hot prior to starting work but soon as i touched the work piece ....death.

MY new one - at a significant number x more of a cost after rusty mac of this parish who does these things for working and thus knows more than i .... recomended i buy this item which is still not mega bucks as far as solder irons go i see but still significantly better .... deore/slx vs supermarket megashift sorta level ... ie one works and the other does stuff but not what its supposed to 😀

I highly recommend a gas powered soldering iron kit for the hobbist, less risk of overcooking components and will come with different shape n sized tips making the job a lot easier.