Basic Soldering Questions

[meths]

I'm just about to order a Weller Sp40 soldering iron and some solder to have a go at removing some components from an old motherboard and resoldering them before I try to fix my PC monitor but I'm a bit confused by the labelling on rolls of solder.

Is resin and rosin core solder basically the same thing and if so would Weller EL60/40-100 (1mm thick) solder be okay to use?

Is the Weller SP40 soldering iron adequate for this type of work?

I'm not looking to break the bank here. If I find I have a knack for this type of work and want to take on a bigger project later then I'll get some decent kit.

[selldoor]

Re: Basic Soldering Questions

I havent looked is the sp 40 a 40watt - if so its a bit on the light side for motherboards.
Ok for most monitor/tv power supplies.
Resin=rosin you will also need some desoldering braid and/or a pump and some separate flux.
Solder should be ok - some people prefer 0.75mm.
This is only my opinion if you use the search above you will find lots of posts.

[selldoor]

Re: Basic Soldering Questions

You dont say where you are ordering from - you may want to check out CPC
they currently have a free post/handling offer.

[mariushm]

Re: Basic Soldering Questions

I use Multicore 63/37 0.56 mm with no-clean flux inside it.

0.56mm is great diameters for motherboars and tiny solder points.
Monitor power supplies generally have larger pad sizes so such small solder wire isn't necessary, you can work with a bit larger diameter, but I would still stick to something less than 1mm.

It's easier to control the amount of solder, you want to put a bit of solder on the hole pad, see the solder go liquid from the heat and the flux work and have the solder go inside the hole a bit, then you can add more solder to finish the solder job. With large diameter wires, you often don't have such fine control.

63/37 solder is a bit better than 60/40 because it transitions from liquid to solid within a very small range, pretty much at 183c. So as you add solder to the pad, you can just remove the solder tip and the moment the temperature drops, it's solid.

60/40 stays liquid within a larger temperature range, a few degrees around 180c, so even after you lift the solder iron the solder will stay liquid a bit so you have to be careful not to move the component leads or whatever you solder.

For monitor power supplies, you don't really need solder sucker and wick, the holes are large enough that you can just add a bit of solder to the pads the leads of a capacitor or other component go through, heat both pads and the solder and wiggle the component out. The holes will be large enough that they won't be blocked with the old solder.
If you're on a budget, the wick is more useful than the solder sucker.

Otherwise, yeah... that Weller is OK to fix monitors, but you'll probably have a bad time practicing on motherboards.

That iron needs some time to reach the high temperature because it doesn't have any temperature control, it just has a heating element that runs at constant temperature inside.

Motherboards have a lot of copper inside, they're made of several layers stacked on top of each other, so the moment you put the iron tip on the part you want to desolder or solder, that copper will cool down the tip and the solder iron will need some time to recover.

If you can afford it, a soldering station is a much better deal, as they let you set a temperature and have feedback so they put more power in the heating element at the tip when they detect the tip cooled down. They simply work much better.

This station for example should work quite nicely: http://uk.farnell.com/tenma/21-10115...-uk/dp/2064549

Not worth it if you only want to fix your monitor though.

[retiredcaps]

Re: Basic Soldering Questions

I'm not looking to break the bank here.

For my first 15 to 20 lcd monitor repairs, I used "sort by lowest price" 40W irons off ebay which generally cost less than $4 USD + free shipping.

They obviously aren't the greatest quality, but it worked well enough because the lcd power boards are generally single layer boards. Eventually they tip deteriorates and the tip temperature is unknown/unregulated.

Later, if you like electronics, you can always invest in a better solder station.

[mentholflash]

Re: Basic Soldering Questions

hi mate
i found when starting of you will break less parts using a quick chip kit for removal
regards

[meths]

Re: Basic Soldering Questions

Ended up buying a 40w starter set for £14.99 and did my repair.

If I use it much I'll buy better kit later on.

Thanks for the advice.

[y_not]

Re: Basic Soldering Questions

meths,
How did you come out on the repair, did it go OK?
The big question is, did it fix it and does the monitor work OK?

I use Multicore 63/37 0.56 mm with no-clean flux inside it.

Good stuff mariushm. I'm learning a lot from your post.
Which of their solder do you use?
I found the following no-clean leaded types.
C400 = ROL0
C502 = ROM1

I can't see the need for it though, as it's 2x the price of Kester!!

This station for example should work quite nicely: http://uk.farnell.com/tenma/21-10115...-uk/dp/2064549

I haven't heard of this brand.
Is it a big name I just missed, or are they one of those Chinese Hakko clone rebranders? Do you use one?

Is resin and rosin core solder basically the same thing...?

Resin=rosin...

Very true, good answer to keep it simple.
But I would like to clarify, also keeping it rather simple. That "resin" is still tree rosin, it's just refined with some or more impurities removed. Instead of simply straight out of the tree, more or less.
However, those impurities are what help it to deoxidize the joints, so they can't remove too much of it. Otherwise they have to add synthetics back in to augment the refined rosin (resin).

It's ultimately supposed to just be "cleaner" residues.
At least that's how I have always understood it. Gathering from my knowledge of such things, going back to my days of playing a stringed bowed instrument.
Rosin/resin is very important stuff with those and each has a slightly different sound. So nerds like me learned the difference.

IIRC. Rosin produced a more rich and warm sound, with resin producing a more sharp and clean sound.

[mariushm]

Re: Basic Soldering Questions

It's Multicore Crystal C502 ... afaik it was discontinued a few months ago by Multicore.

See

* https://tds.us.henkel.com//NA/UT/HNAUTTDS.nsf/web/18CF51B386A96A6E8525768C007205EC/$File/CRYSTAL%20502-EN.pdf
* https://cdn.badcaps-static.com/pdfs/...2ae62eb2e5.pdf

C502 provides the following product characteristics:
Technology Solder wire - Cored
Activity Medium
Product Benefits • No clean
• Clear residue
• Good wetting
• Fast soldering
• Mild odor
• Pb-free and SnPb alloys available
IPC/J-STD-004
Classification
ROM1

Tenma is Farnell / Newark / Element14 's brand, a sort of catch-all brand for the stuff they get from various OEMs.

That model is a rebranded AT938D : http://www.atten.eu/solder-rework/at...150-450-c.html

Same model is available in lots of places under various brands, for example same station is sold by Circuit Specialists under their name here:

https://www.circuitspecialists.com/s...watt-3dlf.html

It's a Hakko 936 clone more or less, it uses tips that are the same as Aoyue (another solder station manufacturer) and are pretty much compatible with the Hakko 936/888 tips... see

If I remember correctly there's a few mm difference in length between the Hakko and these other tips, so the temperature can be off by a few degrees if you use these Atten/Aouye tips in a Hakko or the other way around, which isn't that big of a deal... they still work fine.

I bought a Hakko 936 on eBay, from a guy in Israel, so original, native 220v+ version.

I'd have no problems buying that Tenma if I were to need a soldering station today.

They're clones of 936 like I said, easy circuits, basic, simple to repair if needed.