Man, there has been... a lot of arguing here about this.
I found the video by the way, here is a timestampoed link on what I was talking about:
(EDIT: Seems the site's embedding ignored the timestamp. It's at the 20 second mark)
for flex abrasive, you can put rubber/silicone or leather on a dremel or 1/4 inch rotary in a burr or use it in a eraser. the one in a eraser will be milder grit. Not sure if they have specialty ones for really tough work. I have some slightly flexible stones (idk if its 500 year old rubber that aged or just like tar+sand bars) for fine stoning by hand, but its like a airplane soap.
I don't want something that would require another tool like a Dremel to use, I wanted something simple that I just use with my hands like those Scratch Pens that were mentioned.
fiber scratch pens will scratch the shit out of what your doing. its fine for soldering but IDK if you wanna do that to a relay or switch, it looks chewed up after wards. Keep in mind switches and relays have special coatings, some of them, so you need to be as mild as possible to get any results.
Not sure what you mean. What would be the problem of scratching the leads of a relay or switch? In case there is some confusion, I am only talking about scratching the leads of such devices that you would solder to, not cleaning the entire component itself, just removing the oxidation from it's leads so solder will adhere better when it's too corroded for even flux to help that much with. I am also only talking about preparing the component for soldering, not for doing anything to it after it has been soldered into place.
the tooth brush is the most mild. followed by a stiff brush (stiffer nylon), then brass, then steel, then stainless steel
When you're talking about the other brushes, do you mean a scratch pen or an actual paintbrush-like part?
What hardness/material would you recommend for the leads of a component? What about the pads of a PCB? I know that the pads/vias can be a lot more sensitive, and old electronics even more sensative than a modern PCB. Would I need a different one for both modern and old PCBs?
How it all works out and what order you should go, it really depends on how much experience you have, but trying a toothbrush first is a safe bet.
Basically a beginner. I don't see how a toothbrush would help though, that would be much too soft. I only saw people using those to clean flux off, not the actual components.
For any parts that are slightly corroded/oxidised, I use plumber's solder flux. It is not really suitable for electronic assembly, but when "needs must" it works really well. Just wash off the residue with an old toothbrush and plain tap water afterwards.
I don't think it's a good idea to use any type of flux or solders meant for plumbing for electronics, especially as I am not that experienced with soldering yet.
adjusted for different degrees of stiffness
Yeah, those look like what I was talking about. Just not sure which ones to get for electronics since most are advertised for other uses. And for different uses.
I assume that for cleaning the leads of a component I can use something much stiffer/abrasive since scratching the leads would not really matter?
Though from what I understand, the pads and vias on a PCB would be much more sensitive so I would need something far less abrasive?
And further still, if I am dealing with repairing or modifying very old electronics the pads/PCB might be worn out and I would need something even more sensitive? I hear that many people have managed to lift or tear a pad from simply attempting to desolder something on such old boards.
Do you have any recommendations for what materials/brushes/types of these scratch pens to use for these three scenarios? Or if I even understood the three scenarios above correctly?
You missed the point: the working end of that is the other end: it’s an eraser shaped like a pencil, with the actual eraser encased in wood. Basically a pencil with eraser as the lead instead of graphite. The brush is just for brushing away eraser dust.
I see, I didn't realize it had another end.
And that’s exactly the thing I was going to suggest. I use one regularly for exactly this purpose. It’s abrasive enough to make quick work of oxides, but gentle enough to not immediately eat through the leads.
They exist in both regular eraser (for graphite) and ink eraser, and I’d recommend getting both, so you can use the gentler eraser for more delicate items. Faber Castell sells a few variants.
Eat through the leads? I thought the leads were just a solid piece of metal? Do they normally have a coating or something I should not scratch through like the tip of a soldering iron would have? And do you have any recommendations for what to use on both old and new boards that I mentioned above?
I also love the fiberglass pens, but reserve them for tougher cases for the following reasons:
1. You must METICULOUSLY clean up the little fiberglass fibers that break off in use, because otherwise you’ll end up laying your hand on them, where they’ll embed in your skin and cause itching. The rubber eraser dust poses no such dangers.
2. Fiberglass pens and their refills are more expensive.
Would rubbing alcohol and a soft toothbrush be enough to clean them up?
I don't trust myself with the fiberglass pens, and usually use a small scrap of sandpaper/cloth. It's crude but fine for DIY stuff and usually meets my needs (but it will damage the component lead somewhat, since it's so aggressive). The eraser method works surprisingly well (without any noticeable damage), the photos show switch and wire cleaning with the eraser.
I tried that but I just couldn't get the sandpaper to make enough contact with the leads to clean them well, and it's not something I would want to use on a PCB itself.