New to electronics, what soldering iron and what solder

[Ali8bongo]

hi
Firstly I think this section of the forum matches my question the best, but if it doesn't feel free to move it. I am new to electronics an have decided that I want to try and do some of the basic electronics kits that they have in maplin, for instance a doorbell, or a light activated switch and I was wondering what equipment I need. firstly I know that I need a soldering iron, I think it's meant to be one that's between 15w and 30w (correct me if I am wrong) and I could get a mains powered one to keep thins simple. secondary I know that I need to get solder, but I'm not show which type? I think it has to be a special type if it's gong to be used on pcbs. Finaly I need a multimeter, are there any features which the multimeter needs to have. one last thing do I need anything else for instance a fume extractor, or any other accessories baring in mind that I will probably only be doing a kit every other weekend.
thanks in advance

 

[KJ6EAD]

You only need the simplest and most basic tools for what you propose though better tools are less frustrating and more pleasurable to use. If you're going to use a fixed wattage iron, get the higher wattage. Try to get a soldering iron tip that's described as a chisel or screwdriver tip and about 1.5 to 2mm width. Use the thinnest 63Sn/37Pb or 62Sn/36Pb/2Ag solder you can find (.8mm or less, preferably .5mm or less) with at least 2.2% flux (more is better). You also will need small diagonal wire cutters for trimming leads, needle nose or smooth jaw pliers for lead forming and additional flux for reworking/reflowing joints. Some kind of tool to hold small circuit boards is also useful. Don't forget a solder sponge and some kind of flux remover, possibly just isopropyl alcohol.

You don't need anything special in a meter but if you can reliably anticipate your future needs, that will influence your choice. You can get a little bit of meter for $10 or $20, a lot for $50 and additional capabilities above that.

You won't need a fume extractor as long as you have plenty of ventilation. Many hobbyists just use a small or slow fan to create a little air flow across the work area to carry fumes away from their face.

 

[Ali8bongo]

Thanks that has cleared up all my questions accept I was wondering about 2 things. Firstly what does flux do and is it necessary and secondly could I just use a normal sponge instead of a solder sponge.

 

[KJ6EAD]

Flux cleans the metals to be joined by the solder, reduces the surface tension of the solder, excludes oxygen from the joint and holds heat in. Watch this video, at least twice.

By the way, you'll probably want to use RA or RMA flux. You can make your own from pine sap or from rosin scraps but it's easier to buy.

The sponges used for soldering are made of cellulose. This is the same type of sponge that you buy in a package 4/$1 at the dollar store. They are hard and boardy when dry and are often compressed flat when you buy them and expand when wetted. Cut some slots and holes to aid in tip cleaning (easier to cut when new and flat).

 

[davenn]

Hi Ali8bongo

welcome to the forums

just to clarify.... You DONT need to buy separate flux for the solder.
you just buy rosin cored solder its the normal way these days, has been for a long time

Dave

 

[KJ6EAD]

Dave, you apparently didn't read my first post. This provides me the rare opportunity to quote myself.

Use the thinnest 63Sn/37Pb or 62Sn/36Pb/2Ag solder you can find (.8mm or less, preferably .5mm or less) with at least 2.2% flux (more is better).

...and additional flux for reworking/reflowing joints.

To say that no additional flux is needed is to assert that a novice will not have to rework a joint or that they must be prepared to desolder with wick or suction. I recommend having at least one size of solder wick in the beginning kit but then many prefer to reflux their wick before use so flux in addition to that in the solder wire becomes necessary either way unless you use a suction desoldering tool.

 

[CocaCola]

I have to agree, additional flux is not a necessary item, but damn it comes in handy... If you don't have separate flux you can always flood the joint with flesh solder and just remove off the excess solder. basically just using the flux cored solder for it's flux...

I find a stand alone flux almost invaluable when doing manual cleaning up of finer pitched small SMD chips...

Ali8bongo what is your budget? I personally recommend an adjustable solder station, they can be had for about $40 or so and IMO are night and day vs a cheaper fixed wattage stick iron...

http://www.circuitspecialists.com/csi-station1a.html

I will recommend that particular solder station all day long, and even all night long! At $30 it's one hell of a bargain... Yes, it's just a re-branned made in China model that you an find from several companies but the darn thing just works! I suspect you are in the UK since you mentioned Maplin so find a UK supplier of this same re-branned iron... My first one lasted 5 years of nearly 8 hour daily use before the heating element gave out, but it only cost $12 to get a brand new wand and I was up and running again, and had a new wand and tip to boot ... You can also get a bunch of reasonably priced different shape tips...

Again yes it's a cheap made in China iron and it's not perfect, the black paint on the base will start to flake off in short if you use it all the time, so it won't stay looking pretty but that is only superficial and doesn't effect performance... This particular iron performs quite well, and could easily be argued to perform as well as stations costing exponentially more...

BTW I have use $800+ Weller solder stations when I worked for Motorola, they were FINE devices made to last forever, but it's a hell of an investment and thus not for everyone... For the casual hobbiest or even small/medium time business I would place my money on these $30 stations, they simply work and they work well no matter what the naysayer might bag on them for...

 

[Ali8bongo]

Thanks everyone for the replys so far, so I have learnt that I need these 5 things, a soldering iron, solder, multimeter, solder sponge and additional flux. I'm not sure wether or not it would be worth getting an adjustable heat soldering iron or a soldering station if to begin with I will only be doing the occasional kit. If I am just doing the occasional kit wouldn't I just be better of with a cheap chinese one?
Thanks for all the replys so far.

 

[KJ6EAD]

This is admittedly a small point but in some ways, kit construction argues in favor of a better temperature controlled iron. Many, perhaps most, kits are single sided boards using thinner copper, lower quality boards and weaker glues than we'd like. All other factors being equal, a better iron allows you to apply just the right amount of heat for the least time and thereby minimize the risk of a lifted pad.

That clone of the venerable Hakko 936 that CocaCola linked is pretty solid. I've had a real Hakko 936 for about 15 years now.

 

[davenn]

I knew there was a good reason not to use that horrible thin solder

in 40 years I have never had to use additional flux



D

 

[CocaCola]

in 40 years I have never had to use additional flux

Can I asked how often you do rework on small smd packages? Even cleaning shorts between pins on manually placed TSOP and TQFP is so much easier with a drop of supplementary flux... Yes, I can do it with more solder as well but damn the flux straight up just works so much nicer... Heck a drop of flux even helps drop out a DIP package by keeping the solder clean and fresh...

I'm not saying you need it but based on my experience it can really make life easy sometimes...

 

[davenn]

interesting comments maybe I should try it some time
always willing to try something different

current employment is all SMD. Previous employ was a little SMD, the one before that was total SMD. even a lot of the stuff I do at home is SMD (Amateur radio gear)

cheers
Dave

 

[Ali8bongo]

Thanks for all the replys everyone I have know ordered the things that you have reccomended including the additional flux.
Thanks