Solder diameter to use for Pi Grrl 2


I’m going to be making the Pi Grrl V2 in a month or so, but am wondering what size solder I should use for the project, is there a rule of thumb to know what size is for what purpose?

I read that the thicker the solder the higher the melting point is, and that it the components can melt before the solder does if it’s too thick.

In the pimoroni store they have 0.5mm, 0.8mm and 1.0mm, I also read that 0.5mm would be good for soldering wires, but I wouldn’t just be soldering wires as need to solder some buttons to a PCB also, so I thought I would go down the middle and opt for the 0.8mm or would I be best getting some 0.5 one or all of the other sizes.

I also haven’t solder before this is my first soldering project.


For my two-pennyworth…

I use the 0.8mm solder and it is good for all-round small to large jobs. The 0.8mm gauge is small enough for fine small joints and you simply feed as much in as the joint needs for bigger joints.

Trying to use large gauge solder on small joints can lead to excessive size solder blobs shorting adjacent pins - making a solder sucker device a necessity and, since solder isn’t particularly cheap, there’s no point in using particular sizes for particular jobs by buying various gauge reels.

Go for the middle-size 0.8mm solder and it should be good for anything.


Thank you very much for taking the time to write a well thought out post, with lots of good information!

I was hoping that would be the case, but literally had no clue with this project being my first.

Oh I don’t have one of those, I shall invest in one just in case I need it. I literally just have a soldering iron, and some helping hands thing.


do you also have a stand for your iron?

something like this would be ideal if you don’t :


Yes, Thank you for the reminder, I have bought a soldering station type thing, and it has the helping hands, a stand for the soldering iron when not in use, and a cast iron base for capturing random bits of solder that i’m likely to get everywhere, at least for the first few times.


If you don’t have one, a sponge or soldering tip cleaner might be useful for cleaning the soldering iron tip.


Oh, no I don’t have one of those, how often am I likely to be cleaning it? I presume after every job?


A damp bit of kitchen towel will be fine for a beginner (placed in the recess in your helping hands) and it’s all my dad (pro-solderer) has ever used. You’ll want to be wiping it off occassionally during jobs just to keep it free of excess solder and rubbish.


I see ok thanks, I will give that a try to begin with and go from there :)


You might find this page helpful;



After a few sessions of soldering you will just know when to clean the soldering iron tip - when the tip gets too much solder on it or flux particles burn on it and certainly after its been on the stand for a while.

Cleaning will be a very regular, almost automatic, task followed by tinning the bit before the next few solder joints. A clean, fresh tinned, bit makes soldering much easier and quicker to do and will produce good looking joints that you can be proud of too.


Having a read of that now! I read elsewhere that lead based solder is easier to work with as it has a lower melting point, and my soldering iron came with that solder also.


Agree, although leaded solder may be frowned upon it does seem to flow better and is much easier to make clean pretty joints as it melts at a lower temperature than the unleaded kind. Just wash your hands after using it especially if you’ve taken a break to eat something.

I wouldn’t recommend wearing gloves with leaded solder either as it can affect your grip - just avoid being too close and breathing in the (flux) fumes and wash hands after - lots of folks have been using leaded solder for a very long time without problems.

Just take your time and don’t rush things - once you get the hang of it you’ll wonder why you didn’t start doing it sooner. :-)


Thank you for the reply, reading the ultimate guide to soldering above the pimoroni guys seem to think different, but this maybe for other reasons like the conditions lead solder is obtain in and so on.


Sorry to revive a semi-old thread, but my helping hands and the others that I have seen all use alligator clips that are metal or perhaps aluminium tips (not 100% on the material used as mine doesn’t say).

Are these safe to use to hold a pcb, especially when it’s a fairly crowded pcb which means the alligator clips touch some of the existing solder points or other connectors on the board?

Also if I was wanting to solder some wire to a battery is that safe to do, don’t want to end up on fire! I kinda need all the practice I can get with being new at soldering so I figured i’d have a stab at replacing the battery on my toothbrush, it no longer holds a charge and trying to cut the battery connectors to the correct shape to fit them through the holes in the pcb is a challenge, one at which I failed, although this was mainly due to inadequate tools and breaking off the battery connector on one side.


If you are worried about shorting something with the metal clips then the simple solution would be to use some thick paper or thin cardboard (e.g. from a cereal packet or junk mail envelope) folded over the PCB then the jaws of the clip placed on the card so it will be clipped firmly and insulated. Keep it simple :-)


Oh yes that’s a super simple yet effective solution, I never thought of doing that! Thanks for the tip!